Thursday, December 29, 2011

Terrible Car Commercials

With all of the money that auto executives spend on TV advertising, you would think that they would be very careful with what they are trying to say about their cars and how they say it. Sometimes things might look good in the boardroom but look terrible on the small screen.

Here are a few bad commercials that I have come across on the internet. Some of them are old and some of them are new, but all of them are pretty bad. Many of the horrible ads that I have seen are bad because they are now so old, and the car they are advertising is now known to be so bad, that the commercials can only make you laugh. Some of the ads are just bad, and were always bad. Either way, if you can at least have something to laugh at, it’s worthwhile taking another look.

Here is just a few for now there will be more, later.

Datsun 280ZX Black Gold

This advertisement is from 1980 which should be abundantly obvious to anyone who actually remembers that year. This ad really doesn’t need any explanation because the terribleness of it all is pretty easy to see. What is up with that dopey kiss?

1986 Ford Taurus Introduction

This is an ad that was probably very effective because it has a catchy tune, shows the car zooming down the road, and it shows plenty of people reacting positively to seeing the brand new Ford Taurus. This was the first year of the Taurus so it was totally new to the world and this commercial does make it look somewhat exciting. The problem with this ad is that the 1986 Ford Taurus was such a terrible car that it is hilarious to see the poor saps in this ad get so giddy over something that is going to have a bad transmission and blown head gaskets after only a few miles.

Chrysler 200 Imported from Detroit

I got a question for ya...What in the world is this guy talking about? As if Eminem drives a 200. This is a grandma car and putting a rap star in an ad like this isn’t fooling anyone. And what’s with the whole “Imported from Detroit” tagline? Last time I looked at the map Detroit was within the borders of the United States along with both New York City and Las Vegas. The ad also seems to be saying that because Detroit somehow resembles a ghost town that has fallen apart because of the problems in the auto industry, somehow they (the troubled local auto industry) are now able to build a really nice car for your grandma? "This is the motorcity, and this is what we do!" What do you do? 

Ford and Chevy Trucks towing each other

My truck is bigger than your truck…no my truck is bigger than your truck. Girls, girls, you’re both pretty. As if you need to haul a truck hauling a truck pulling a truck. These little tests prove nothing, and are probably faked half the time anyway. Like someone who is about to buy a truck is going to be influenced by seeing a truck towing a mountain. If the Chevy at the end is really towing the mountain, who’s to say that they could just hook up a Ford to the front of the Chevy and then film a Ford commercial of their truck towing the truck that is towing the mountain. And what is the deal with the people just sitting around out in the middle of nowhere as the mountain towing truck drives by? No way is this commercial, or any other commercial like it, is really effective.

Sunday, December 18, 2011

What Makes an Oil Burner

Diesels are on the rise, what makes them so special?

The fuel used in diesel engines is often referred to as fuel oil. This is because it is a longer hydrocarbon chain than those used to formulate gasoline. If some diesel fuel is spilled on the garage floor it will still be there the next day and will not have evaporated like a puddle of gasoline would have. So the fuel is what makes a diesel different from a regular engine. While it is true that the fuel is different, other differences obviously exist that necessitate a different fuel.

Diesels get better fuel economy than gasoline engines, and diesels usually go more miles than a gasoline engine before a rebuild is needed. Diesels make more noise then a gas engine, diesel powered cars are never as fast as gasoline powered cars (naturally aspirated), and diesels may have a tendency to produce nasty black smoke when they are not running right. Many of these things are generally known by anyone who has ever owned a diesel, and these things usually represent the extent of the average person’s knowledge regarding diesel engines but differences run much deeper, and there are reasons why all of the things mentioned above are true, or maybe not as true as they once were.

Various efficiencies affect the operation of every engine regardless of fuel type, and these same efficiencies actually have an impact on the operation many things mechanical. The first one is thermal efficiency. When fuel is consumed in an engine it is burned. This seems easy enough to understand but what is really going on is a conversion of energy. Engines don’t “make” power; they convert it from a potential source to a kinetic source. The energy is in the fuel, and when the fuel is burned this same energy is converted into something more useful which in this case is the motion that makes the vehicle go. More specifically though, the energy is extracted from the fuel by turning that energy into heat. More on how this efficiency affects diesel engine function in just a minute.

The fundamental difference between a diesel engine and a gasoline engine is the way that the fuel is ignited in the combustion chamber. A gasoline engine uses what is called spark ignition (SI) to get the fuel burning. SI uses a transformer style coil to produce a high-voltage spark and introduce that spark via a spark plug, into the combustion chamber. When the spark jumps the air gap at the tip of the spark plug, the heat of the spark ignites the air/fuel mixture. When the fuel burns, the rapid expansion of the hot gases pushes the piston downward in the cylinder.

In the case of a diesel engine the air and fuel are ignited by compression (CI). The compression itself doesn’t actually ignite the fuel, but rather the concentration of heat energy when all of the air in the cylinder is squeezed into a very small space in the combustion chamber. When the air is squeezed the molecules in the air start banging into each other creating friction. This increased molecular energy is manifested as heat. This heat is used to ignite the fuel which then expands and pushes on the piston.

In order for the temperatures in the combustion chamber to get high enough, the pressure in the combustion chamber must also be very high since temperature and pressure are always related. Because of this, diesel engines have a much higher compression ratio than gasoline engines. A gasoline engine might have a compression ratio in the neighborhood of 8:1 to 10:1 on average, but a diesel engine might have a compression ratio of 20:1. This higher compression ratio means that the engine must use more force to push the piston all of the way up but the result is combustion that produces a tremendous amount of torque, and it also causes more power to be extracted from the fuel then what you would get from the combustion process in a gasoline engine. This increased thermal efficiency is the reason that diesel engines get better fuel economy then similarly sized gasoline engines. Gasoline engines turn more of the energy from the fuel into wasted heat instead of movement of the piston.
Cross section of a diesel engine. Note the large injector in the middle that
sprays fuel directly into the combustion chamber.
With the compression ratio being so high in a diesel engine, the internal bits of the motor must be built to handle more abuse and greater forces. This tends to make diesel engines last longer than gasoline engines from a mechanical standpoint. Many of the heavy-duty diesel engines that are used in the big rigs that you see on the highways will go 500k miles or more before they need to be rebuilt, whereas the typical gasoline engine will only go half that distance before requiring a rebuild, and that’s only if you are lucky.
Because diesel engines have such high compression ratios they must also use a different method for putting the fuel into the combustion chamber. Gasoline engines will nearly always mix the fuel with the air, and then open the intake valve to let the two of them enter the combustion chamber mixed and ready to go. This means that the fuel is in the cylinder as the piston moves upward, compressing everything in its path and the fuel does not burn until the spark is introduced. Old gasoline engines used carburetors to dispense fuel into the top of the intake manifold. Multiport fuel injection involves spraying the fuel into the intake manifold right onto the backs of the intake valves.

In the case of the CI engine the fuel is injected directly into the combustion chamber once the piston has moved all the way to the top of the cylinder and all of the air in the cylinder has been thoroughly squeezed into a very small space. The reason that the fuel is injected in the manner is related to the high pressure in the cylinder. If the fuel was already in the cylinder as the piston was squeezing everything together it would spontaneously combust at a point before the piston was at the top of its travels, and ready to accept the force of the rapidly expanding gases. Because the fuel must be injected into this high-pressure situation, the injection pressure at the tip of the injector must be very high. On many newer diesel engines this pressure is around 25,000 psi. In order to inject the fuel at this pressure some very special fuel system components and strategies are required. The injection pressure in a gasoline engine is only somewhere between 30 and 60 psi.

Recently, new technology has been introduced in the world of gasoline engines that allows the SI engine to gain some of the efficiency of the CI engine. This new technology is referred to as gasoline direct injection (GDI) A GDI engine can run with a higher compression ratio but can still burn gasoline, and it can burn it in a manner that leads to more power on less fuel, with more of the fuel being properly consumed which in turn leads to lower emissions. This is a great development that will likely lead to the end of standard multi-port injection as we have known it for the last 30 years.

One of the draw backs to using diesel engines has been in the way that they respond to regular driving about town and on the highways. Diesel engines have traditionally produced an excellent amount of torque but not much horsepower. Think of torque as the force that does the work of moving the vehicle down the road, and the horsepower as the speed at which the engine can apply the torque. Because most people want better throttle response when they take off from a stop light, diesel engines have struggled to become as popular as gasoline engines.

Noise is also a consideration for many people. Diesel engines make a noise that can best be described as a loud deep rattle from within the engine. This noise is produced by the sudden combustion of the air/fuel mixture in the engine. When the air and fuel first ignite the initial blast is like a sudden explosion instead of a controlled burn. This little fireball does settle down and burn in a more controlled manner for producing reliable power, but when it first starts to burn it’s a bit erratic. The sound is a popping of the air from the sudden expansion and does not result from any mechanical parts banging against each other. On newer computer controlled diesel engines that noise is dramatically reduced by the injector squirting a tiny amount of fuel into the combustion chamber to get things burning before then spraying the main volume of fuel into the combustion chamber that is used to produce power. This tiny initial blast, referred to as a pilot injection, doesn't make much noise and it helps the large volume of fuel to begin burning in a much more controlled manner.

In reality the concern of snappy performance, or the lack thereof, that used to be associated with all diesels is really not all that valid anymore. Most diesel powered vehicles on the market now use a turbocharger to increase the horsepower of the engine and give it a much better throttle response. A turbo essentially puts more oxygen into the combustion chamber. The use of the turbo makes a diesel powered vehicle more pleasant to drive, but it does add extra cost to the bottom line when you go to purchase a new vehicle.
The question is often asked, why do we not have more diesel engine options if it works so well? In Europe at least half of all new cars sold are diesel powered, but in the US it is about 1%. The biggest reason that people in the U.S. don’t buy many diesels is because the cost of gasoline here is cheaper than what it is in Europe. The other reason is all of the terrible diesel engine options in the U.S. from the late 70’s and early 80’s. These vehicles resulted from the energy crisis of the 70’s but the problem is that many of these old diesel engines were horribly built.

1984 Ford Escort. The reason that Americans don't like diesels.
What could be worse than a 1984 Ford Escort? How about a 1984 Ford Escort with a non-turbo diesel engine. Many of the diesel engines from this time period didn’t use a turbo so they were gutless. They were not computer controlled so black smoke was normal without proper maintenance. And like all other diesel engines they were noisy. Some of them were just gasoline engines with some modifications to turn them into diesel engines. For the consumer this all meant higher initial cost to purchase the vehicle, less reliability because these engines were not well built, and hassle in finding a station where they could get fuel. Not all of these early diesel options in the U.S. market were that bad, Mercedes and Volkswagen had diesel engines in some of their offerings that were far superior to the ones in the domestic cars and trucks, but they were still gutless and noisy.

Chevy Cruze. One of the new small sedans that will be
available with a diesel engine.
With fuel economy again being a great concern, and with computer engine controls leading to greater efficiency and reliability, diesel engines are poised to make new inroads in gaining market share within the U.S. Companies such as Mercedes and Volkswagen have pretty much always had diesel options in some of their cars sold in the U.S. and the domestics have nearly always had a diesel option for their large pickups. Lately however many companies have begun to offer more diesel options in passenger cars where diesels had never been an option before. Chances are that diesels may yet do well in the U.S. but whether or not they can become as popular here as they are in the Europe remains to be seen.

Diesel Advantages
  • Better fuel economy, often much better
  • High torque
  • Built tougher
  • No ignition system to wear out, i.e. spark plugs

Diesel Disadvantages
  • Higher purchase price
  • A gallon of diesel costs more than a gallon of gasoline
  • Not every gas station has diesel
  • Usually slower than gasoline counterparts
  • Good luck finding a good diesel mechanic that isn’t working on heavy-duty stuff only

Sunday, December 11, 2011

Stupid Car Accessories

One of the reasons that we love our cars so much is that we feel like they are an extension of who we are. We often become one with our vehicles so much so that we become that car and that car becomes us. Just like we dress ourselves each morning to make ourselves comfortable and to also perhaps make some kind of statement, we may also dress our cars with different things to make a statement. Sometimes people either don’t know better, or just have no taste when it comes to expressing themselves through automotive customization, or through personal dress for that matter.

While this list does not include everything it does represent the large variation that exists in tastelessness. The one thing that all of these items certainly have in common is the fact that many people at some point have applied these custom bits to their cars and trucks while saying to themselves, “This is going to look cool!” They couldn’t be more wrong and if they had and true friends, these friends would let them know.

So here is the list and the reason why each of these things is lame. If you have any of these things on your car or truck, please be advised that you ought to remove them if possible because there is a good chance that most people on the road think that you are crazy, stupid, or just have no taste. Many of these things apply to pickup trucks only and it is definitely possible to see many of these things on one truck at the same time. That truck is a book that you can go ahead judge by its cover.

Truck balls

While this list of tasteless accessories does not follow any particular ranking, if they were ranked, truck nuts or balls or testicles if you will, have to be the tackiest thing that you can put on a vehicle. This molded plastic pair of gonads are usually seen on 4WD pickup trucks, and are usually placed there by some hill billy that lacks manners and a sense of what’s appropriate, and certainly what looks cool. These truck nuts were certainly invented by a man rather than a woman because everyone knows that nobody is more obsessed with the male genitalia than men themselves, even straight men. Everything is a contest! Determining exactly what the thought is in purchasing and displaying such things is hard to determine, but it is quite easy to reach the conclusion that plastic truck balls are not cool and show a complete lack of fastidiousness on the part of the vehicle owner.
Tacky? I think a picture is worth a thousand words.
So you can match the color of your truck. Mismatched colors
would be in poor taste don't you think?
Calvin Urination Stickers

These are stickers that depict the comic strip character Calvin, from the Calvin and Hobbes comic, relieving himself on all sorts of different things. These stickers are often found in the back windows of the trucks that have the private parts dangling from the hitch. Calvin peeing on a Ford logo in the back window of a Chevy can be common; in fact Calvin relieving himself on Chevy logos and Dodge logos can be just as common and just as uncouth. Why would anyone feel the need to advertise their dislike for something as innocuous as a rival car company or sports team? I have even seen stickers of Calvin going potty on political figures or government entities. Every one of these stickers is tacky since human bodily functions displayed in cartoon depictions are never cool.
Take your pick. Either way you're lame.

This is the protective cover that goes over the grill and the front part of the hood to “protect” the paint, not the article of clothing worn by a woman to support her abilities. Car bras never protect the paint they actually destroy it by trapping dirt and moisture and every other body finish destroying agent against the paint. Even if none of that stuff does get under the bra, this useless contraption blocks UV rays from hitting the car evenly so you end up with two tone paint.
Clear bras just turn yellow and start to peel off so they are not much better.
Looks okay now but it will look bad soon.
Besides damaging the car’s finish, bras just look bad. They rarely fit properly for very long before they start to sag and bunch and the straps become stretched, and then the very thing that they are meant to cover or protect ends up looking terrible because of the sagging and hanging of it. I think this same thing happens to the bras of the female human type. Not only this, but they also cover up the front end of the car which is quite often the best looking part. When I was a kid I had a friend whose parents had put really fancy furniture in their living room but then always kept it covered with plastic. What is the point of having something beautiful to look at and cover it with something that is so ugly? I will not draw any analogy between this point and the female woman type bras, but others might.
Paint damage from wearing a bra.
Stick-On Vents

Little circles on the fender are not cool.
Most little decorative details that simply stick on the body panels with some kind of adhesive from the 3M Company are no good, but currently it seems very popular to stick fake vents along the top of the front fenders. For a long time the venti-port has been a design trademark for Buick as they used to put these on their cars decades ago and have recently started putting them on again. A few other models feature these ports as well. If the vehicle had such trim from the factory it’s a bit better but when the vents are fake, such as they are even on the Buicks, then it’s kind of silly. Anyone can go down to their local auto parts store and put these on their car any which way they want. I even saw a Cadillac Escalade the other day that had them all the way down the side of their vehicle, on the doors and on the rear quarter panels. Tacky, tacky, tacky!

Tailgate Nets

Once again what is the point? Are you trying to make your truck look like you are racing in the Paris Dakar rally? Somehow I doubt that your 1990 Ford Ranger could really look cool at all let alone with a silly plastic or vinyl net for a tailgate. Some say that the reason for using one of these is to improve fuel economy. Mythbusters actually tested this idea to see if it really did help and of course it did not. Sorry but this is another hill billy add on.

Woman Silhouettes

Okay we get it, you like the ladies but what is the point of these tasteless little silhouettes? Some of these are the classic style that has been around for a very long time, and some these have been somewhat newly popularized by a certain clothing brand. The devil woman on one side and the angel woman on the other side fall into this category. What is so cool about a buxom devil woman complete with a tail? Really?  
Is this cool? What is it trying to say?

Lewd References to Other Truck Brands

This is somewhat related to the issue of Calvin and his urination habits but what I am referring to here is so much worse. The statements made in a giant window sticker can be so offensive that I dare not repeat them here, but if you use your imagination you might be able to imagine how words like Cummins or Power Stroke could be turned into something dirty. How could anybody see one of these stickers and think that it will help them say something positive about themselves or the vehicle they drive. Besides, Chevy, Ford, and Dodge all have their respective weaknesses so disparaging the truck of someone else to their faces like this will just make you look even more stupid when your dirty sticker clad truck breaks down.

Stupid Exhaust Tips

When did it become cool to have a fat exhaust tip? These things have been showing up on lots of different cars for a while, but the ones that seem the most down-at-heel are those that are found on little sedans and hatchbacks, or those that are found on big pick-up trucks. I’m not sure if these are supposed to make the vehicle look like they have more power, or are somehow really fast. In reality more powerful engines have a fatter exhaust pipe but this starts at the engine and goes back from there, not just in the last 12 inches of the pipe. Once again an overly large exhaust tip is likely to be found on the back of the pick-up that is also sporting the plastic you know what’s mentioned above.

Other exhaust tips that are not cool are ones that have electric lights in them, or the ones that whistle like a turbo, the ones that are fake such as is found on the Lexus IS, although these are built that way in the factory, they are still lame and almost make the entire car lame. Sometimes a chrome exhaust tip will be added that is a normal diameter but it doesn’t fit right so it sticks out way too far. This makes the vehicle look worse than the stock the tailpipe does. All of these silly exhaust tips do nothing to enhance the vehicle and just look stupid.
Is the size of the exhaust tip compensation for something?
One more thing with exhaust pipes. Stacks are lame. I’m talking about routing the exhaust out at the front of the bed into one or two exhaust stacks. No matter what you do to your truck to make it look like a big rig, it will never actually be one. With stacks in the back of a truck you can’t have a shell or a truck box installed, and the pipes can get so hot that they can damage anything in the bed that might accidently touch them. And of course mixing stacks with overly big tips that light up would be really bad.
Why, why, why?
Aftermarket Spoilers

Somewhere in the neighborhood of 99% of these things look terrible. Most of the time, they are way too big, and make no sense from an aerodynamic standpoint. Racecars use a large spoiler over the rear wheels because these are the drive wheels, and the down force produced by the spoiler keeps them well connected to the road. Much of the time when you see one of these outrageous contraptions riding around on the trunk lid of some compact car, that car is nearly always front wheel drive. These cars really don’t even get going fast enough for the spoiler to even provide any kind of aerodynamic effect other than causing drag and thereby reducing fuel economy. In the late 90’s and early 2000’s many car manufacturers offered some kind of low profile spoiler as a dealer installed accessory. Most of these are tasteful enough that they look okay but they still don’t provide any benefit.
Doesn't that look sporty?
An ugly spoiler attached to a car that is actually something
worthwhile, other than the fact that it's pink.
Body Kits

Someone took the ugly stick to this Honda Civic.
These are the large plastic or fiber glass pieces that fit around the rocker panels, and replace the front and rear bumper covers, in order to give the vehicle a more aggressive or more performance oriented look. I would say about 95% of these body kits look terrible for a number of different reasons. The first is that they rarely fit properly, or they are not installed properly. This leaves theme flapping in the breeze with big gaps, sagginess, and the panels dragging on the ground. When they smack the concrete on every steep driveway approach they get scraped up and cracked, which of course makes them looking even worse. With body kits the only ones that look good are either dealer installed factory options, or ones that are understated. The way to guarantee a good body kit is to actually spend a lot of money on it. The cheap stuff looks bad every time.
How to ruin a perfectly good BMW 3 Series, add
an ugly body kit.

Some body kits are so bad that they actually don’t have spaces for things like the turn signals or marker lights. So when they are installed these lights just get unplugged and eliminated. I’m pretty sure that exterior lights are important, and why anyone would think it’s okay to eliminate one or two of them makes no sense.

Wednesday, November 30, 2011


So now the Chevy Volt is catching fire. This is not to say that the Volt is experiencing a dramatic increase in popularity and sales are through the roof because they certainly are not. What I am saying here is that the Volt has gone up in literal flames a few times after being wrecked. So far this seems like a first for hybrids, as cars like the Toyota Prius have been around for 10 years now without much trouble.

At least one incidence has been reported of a Chevrolet Volt catching fire out behind a body shop while it was waiting for some restoration after having been wrecked. A few incidences have also occurred of the Volt catching fire while sitting out behind the facilities of a crash test center. At least one of these fires occurred after the test center wrecked the car and stuck it out back to specifically see if it would catch on fire, according to CNN. The fires seem to be erupting from the high-voltage battery. Every time one of these cars has gone down in a blaze of glory, it was always days or weeks after it was wrecked, and with every car, GM procedures for discharging the battery after it was damaged have not been followed.

The bad PR has caused GM to offer temporary loaner cars to owners of the Volt while an investigation is being conducted by the National Highway Traffic Safety Administration, just in case the owners are freaking out and afraid of getting burned alive. GM of course is down playing everything saying that it’s not that bad since the fires don’t occur until well after the crash.

So what should we make of all of this? I for one am torn a bit with my opinion of the Chevy Volt.  The topic of the Chevy Volt can be rather incendiary (current fire problems not withstanding). I think it is ridiculous that the federal government took control of GM when they filed for bankruptcy back in 2009, and then forced the Volt to market for purely political reasons. The Volt kindles similar feelings amongst many taxpayers. I don’t have a problem with companies doing things for the purposes of being politically correct, or to advance some agenda. A privately held company ought to be able to do whatever they want to do as long as it’s not illegal. The problem is that even today GM is not privately held and the U.S. taxpayer still owns about 25% of the “new” GM.

The Volt was pushed to market with federal tax dollars, and then congress passed legislation awarding $7500 to anyone willing to buy a Volt in order to ignite interest in this new car. MSRP on a new volt is about $42k so with the $7500 incentive (from the developers and builders of the Volt i.e. the Feds) the price people actually end up paying is about $34k. This tax credit for Volt buyers means that tax payers are paying impractical rich people a large chunk of money to buy something that they will use to make a political statement, or they will just use as a toy. This is the real conflagration of the Chevy Volt

Now having said all of this, the part where I am torn is in that I love the technology that is wrapped up in the Volt. I am a technology geek of the highest order and the Volt does have some pretty cool stuff under the hood that makes it go. I have had a chance to inspect a Volt up close and personal, and I even took it for a spin. The car is without a doubt the most impressive thing to ever bear the Chevy bowtie. The ride is great, the handling is nice, and the gas/electric motor combination provides plenty of pep. The Volt beats the Prius in the quarter mile anytime, anywhere. I think that some alternative fuel vehicle is likely to take over at some point anyway, although it will probably not happen overnight. When it does happen it will be gradual and it will be a result of regular market demand, not the result of anyones political agenda.

The problem is that the Volt is like the U.S. military. While it is great at what is does, and perhaps it does its job better than anything in its class, when considering the overall cost, it’s obvious that things could be done better for a lot less money. Since the U.S. Constitution calls for the Federal Government to fund the military to protect us all, and since I am pretty sure there is nothing in the document that allows the government to build impractical cars, we can be concerned with G(overnment) M(otors), and we kind of have to learn to live with the military scorching cash.

So what about the fires? On the one hand I would ask what do you expect from a government funded project? On the other hand I would say that it is likely much ado about nothing. Gasoline powered cars catch fire all of the time and we still, after more than a century, keep the highly explosive fuel used to power these cars in plastic or metal tanks that are only inches from the ground as these land missiles cruise about and get into fender fights with other cars. If the Volt fires are a big deal then we will see it all unfold shortly. I think that the media loves fires and explosions so they will try to over inflate this entire issue and we can count on hearing about every battery that is set ablaze.

Friday, November 25, 2011

An Idle Car is the Devil’s Workshop

In the area that I live I am not what you would call native. I live in a small town in one state but I am originally from a large city in a neighboring state. Being something of an outsider to this place I have noticed many things that are common here, that are not as common where I am from. One of the things that I have noticed to be so common is endlessly idling vehicles.

Here in our little town it is very common to be in any parking lot and find an empty vehicle running in one of the stalls. I’m sure that this is a common thing in many places; it just seems more common here than in other places where I have lived. Perhaps it is a cultural tradition and in talking to some of the natives about this situation many of them say it is because of the cold harsh winters. The problem with that theory is that you see it almost as often in the summer as you do in the winter. I think that perhaps the biggest reason this doesn’t seem so noticeable in the big city is that if you let your vehicle run unattended, some ne’er do well might decide that they need your car more than you do. This is probably less of an issue in a small town.

With gasoline being as expensive as it is, and with vehicle maintenance being such a nuisance at times, why would anybody want to burn so much fuel and put so many hours on their engines and get essentially nothing in return? Is idling a vehicle really necessary in order to warm it up on a cold morning? What kind of wear and tear occurs when a vehicle is not warmed up? What kind of wear and tear occurs when a vehicle is idled excessively? All of these are valid questions.

Let’s start with the issue of warming up that engine on a cold winter morning. Many people will let the engine idle for 10 or 15 minutes, to then drive the vehicle 10 or 15 minutes to work. The logic that many of them use is that it is bad for the vehicle if you don’t give it a chance to warm up. Some say that you have to let it run so that the oil can circulate through the engine. They say that idling the engine and letting it warm up gets more oil to critical engine components that would be starved for oil if you were to just get in and drive. This is not true.

The fact of the matter is that even when ambient temperatures are very low, it only takes a few seconds for the engine to build oil pressure and get oil flowing to all of the critical parts of the engine. The oil pressure actually builds easily when the engine is so cold so pressure wouldn’t be the issue anyway. The oil does flow more slowly when the engine is cold and it does take a bit longer to get to every place where it needs to be but we are still only talking about a few seconds longer than it would normally take at higher temperatures.

A crankshaft bearing with scuff marks made by the crankshaft
rubbing on the bearing.
The real issue here related to excessive idling and engine oil is the fact that when the engine is at idle the oil pressure is at its lowest. Engine oil pressure is responsible for supporting the crankshaft and the camshaft when the engine is running. Normal oil pressure on a warmed up engine running at 2000 to 3000 rpm is about 60 psi. At idle this pressure falls to about 30 psi. When engine oil pressure is low, such as it is at idle, then there is a greater chance that the crankshaft will actually touch the bearings that are wrapped around each crank or cam shaft journal. As an engine wears under normal conditions these engine bearings will gradually become thinner, but they should ultimately last forever. When oil pressure is low it increases the rate at which these bearings wear out. When an engine has very high mileage and the bearings are already somewhat worn, excessive idling can be even more damaging because engine oil pressure can fall to something as low as 5 to 10 psi. This is because the tight tolerances between the thicker or newer bearings and the shaft journals cause the oil pressure to run higher.

Some people say that a car uses more fuel if you shut it off and restart it, than it would if you just let it idle for a few minutes. This is completely untrue. In the old days some cars might use a bit more fuel on startup then they would if they idled for a few minutes but even then it was only under certain situations. Some people also say that you can wear the starter out if you stop and start the vehicle too much. Of course something is going to wear out if you use it. By this logic then we should just never drive the vehicle ever because it will wear out the tires and the engine. Assessing how quickly a starter wears out when a vehicle is stopped and started rather than idled is pretty much impossible.

The biggest issue in relation to fuel consumption and an idling engine is that a car that is running at idle is getting zero miles per gallon no matter how efficiently it is burning the fuel. If you complain about bad fuel economy from your vehicle, or you complain about how much it costs to fill ‘er up, but you idle your car regularly, you are only making matters worse. They say that the way you drive your car affects your mpg’s and this is completely true. Many of us would never drive our vehicles in a way that would compromise fuel economy, or cause harm to the engine (no matter how miniscule), yet many people will idle their cars at least 30 minutes every day.

Also in relation to overall efficiency is the fact that vehicle emissions are often higher when a vehicle is at idle compared to when a vehicle is moving down the road. Fuel control is optimized for rpm ranges that are off idle. The catalytic convert also has a tendency to cool down a lot, so much so that the chemical reactions that reduce the level of pollutants in the exhaust stream cease to occur and the exhaust becomes more harmful.

This decrease in efficiency also means that the carbon that is contained in the fuel does not get fully oxidized so it tends to just buildup in the combustion chamber, and in the piston rings, and on the valves, and in other places in the engine. When this happens, the carbon acts as an abrasive to slowly grind engine parts down and disrupt the smooth and efficient flow of air and fuel through the engine. Hydrocarbons will also build up in the crankcase oil causing it to lose its ability to lubricate internal engine parts. The buildup of carbon in the oil will require the engine oil to be replaced more often.

I think that most people that are spending a considerable amount of time warming up their cars, or the people that leave it running when they run into the Loaf & Jug, are either not thinking about it one way or the other, or they are thinking that they don’t want the inside of the car to get cold. How cold is it going to get if you shut the engine off while you are filling up with gas, or running into the store to get a cup of coffee?

Truthfully, letting a car idle really doesn’t warm it up very quickly, nor does it warm it up very thoroughly. The fastest and most effective way to warm up a car is to drive it. A car that requires 15 minutes to warm up the engine just idling can be warmed up just as much in about five minutes if it is just driven normally. This will not warm up the inside of the car but if your commute is longer than about 15 minutes then you will be plenty warm inside the car by the time you get to work. What about the rest of the car’s systems? When a vehicle idles for an extended period of time to warm up the engine, this does nothing to warm up the transmission or anything else on the car. Don’t these things need to be warmed up as well? No they don’t, or at least not purposely. Just get in the car and drive it like normal and all warming will be taken care of quickly and effectively.

Back when every car used a carburetor for fuel metering, it may have been advantageous to let the car warm up a bit on very cold days because the choke needed a chance to open a bit. The choke was a device that helped the engine to run with a bit of a rich mixture when it was cold. Sometimes automatic choke function was not that reliable and the car didn’t really run very well until the engine warmed up and the choke opened all the way. Some old carbureted vehicles had a problem with ice buildup on the venturi. Considering that the venturi works sort of like an airplane wing, we know an airplane wing is useless with a bit of ice on it, and the same applies to a venturi. Most vehicles had a system meant to prevent this kind of ice buildup, but they didn’t always work. After the engine warms up there is no problems with ice on the venturi. Modern vehicles (most cars built within the last 25 years) are fuel injected so they don’t have any of these problems that in the old days were avoided by letting the car warm up before driving it.

What about a diesel engine? Isn’t it true that the rules are different for diesels? I would ask, how could the rules be any different? A diesel vehicle at idle is still getting zero miles per gallon. A diesel engine still has a crankshaft that is supported by engine oil pressure that is best kept up. A diesel engine still burns a hydrocarbon fuel that when not fully oxidized in the combustion process leaves carbon deposits in the engine. Diesels are more efficient at idle than their gasoline counterparts, meaning that they don’t burn as much fuel compared to how much power they produce, but this rule applies to all operating ranges and not just idle. Nothing magical happens when a diesel engine is idling that makes it okay to do so. So why do the big diesel trucks idle at the truck stops so much? Probably to keep the driver warm while he is in the sleeper of the cab, or so that he can run his TV and microwave. Other than that the trucker does this for another reason. Quoting Tevya from Fiddler on the Roof that last reason is “Tradition!”

Since we live in a free country we can let our vehicles idle all day long if we want to. Everything that I have said here can be disputed in some way, or deemed unimportant by some, and that’s okay. Everything that I have said is true no matter how you spin it. If you don’t care about saving fuel or extending engine life, then you have just wasted the last few minutes reading this article. If you value your engine and you value your fuel almost as much as gold, then consider some of the things that I have said here and see if you can change some of your habits. Your car and your wallet will be glad if you do.

Sunday, November 6, 2011

The Worst Cars In the World

Next in the ongoing series: Fiero actually doesn't mean fire in some foreign language

Built from 1984-1988, this thing was a disaster in spectacular fashion, and a supreme piece of junk! The concept represented something totally different for Pontiac and GM. The idea had so much potential and it really wanted to be a cool, sporty, mid-engine sports car, but what it ended up being was a terrible, unreliable, fire-ball on wheels. The reason I say fire ball is because of more than one problem that came about after the car was released that had a tendency to make the engine compartment erupt in flames and burn the car to the ground.

With the front suspension of a Chevette and the rear suspension of a Citation, what could be bad? To clarify, the rear suspension that came from the Chevy Citation was the front suspension from the Citation, but it was used on the rear end of the Fiero because the Fiero was rear-wheel drive, and the engine options on the Citation and the Fiero were very similar. Regardless, any time you hear the words Chevette, Citation, and Fiero together, you know that the discussion is not about anything good. Despite the suspension design the vehicle handling was not too terrible because of the mid-engine setup, but everything was so poorly executed that it had a lot of maintenance problems. “Maintenance problems,” is kind of a nice way to say that it fell apart right and left and there was nothing that anyone could do about it. The car was competition for the similarly mid-engined Toyota MR2 but there is absolutely no comparison between the two.
1984 Pontiac Fiero
To make this bucket of bolts even better (worse), the base engine was the 2.5L pushrod boat anchor that was found in other piece of junk Pontiacs of the day. These four cylinder engines were the ones that were catching on fire. They would catch fire when the engine would throw a connecting rod through the side of the block and spill the contents of the crankcase onto the hot exhaust. Car-b-que! Flames erupting from the engine compartment were a bad thing but considering the fact that the flames resulted from dramatic engine failure, you might as well go ahead and let the thing burn down because it’s going to need a new engine anyway. Talk about adding insult to injury. It’s one thing to have the engine break apart, but it takes a real piece of work to then only seconds later catch on fire.

Besides blowing up the engine to catch everything on fire, the vehicle was also thought to have a wiring problem in the engine compartment that could result in fires. Wiring connectors could get hot being in the wrong places in the engine compartment. When the insulation melts off of electrical wires and the wires touch each other or short out on the body or engine, the amount of heat that results has a tendency to burn things to the ground. Because of the way the cooling system was designed, and the fact that the engine was in the rear, the engines also had a tendency to overheat because air would become trapped in the cooling system and these air pockets would block the coolant from circulating.
1988 Pontiac Fiero GT a much better car than the original but...
The initial four cylinder engine was good for all of about 97 HP and it clattered like your grandma’s sewing machine. The V6 wasn't nearly as bad, but it was only good for 140 HP. Not having much power is really not the worst thing, the biggest problem is that the entire car was so unreliable and had so many mechanical problems, it didn't really matter what kind of engine it had, it didn't matter how it looked, how it handled, or how it was designed. The fact that it was pure unmitigated garbage is the biggest sin here and it is the thing that makes it one of the worst cars ever made. The second generation Fiero was significantly improved but it was too late, the damage was done and sales never recovered to a level that would allow the model to survive. If you go to a restaurant and they serve you burned chicken, are you ever going to order the chicken again?
A mid-mounted V6 that only produced 140 HP
This car being so terrible does not preclude some people from liking it. The internet is loaded with clubs and discussion boards that allow Fiero aficionados to come together and commiserate on all things Fiero. Despite the fact that this is such a terrible car, if some people like them so much that they want to band together online, or on the weekends, and fix them up, talk about them and modify them to make them fast, then I say go for it. The one thing that the Fiero has going for it is that it is different. It’s not good, but it is different.
A real abomination. This is not a Lamboghini Diablo, it is a Pontiac
Fiero dressed up with a kit.

Friday, November 4, 2011

To Let a Good Idea Languish

What are manufacturers thinking sometimes?

Sometimes an auto manufacturer will come up with an idea for a new car that is spectacular. They will put the vehicle to market and it will be a runaway sales success. This new model success will make the manufacturer and their dealers piles of cash from being able to sell cars well above invoice and sometime above the MSRP. People can go crazy sometimes and when they really want something that’s hot, to drive up and down their street in front of their neighbors, they will spend all sorts of money that they wouldn’t normally spend. All of this profit that the manufacturers rake in can be funneled into R&D of the next iteration of their success.

If they have their heads on straight then they will continually improve the car over the years and every four or five years they will completely redesign it in order to keep the auto buying public interested. Human nature is to have a very short attention span, and once we get used to some stunning new vehicle, and it becomes common place on our streets, we get bored. That’s just the way it is.

Sometimes a manufacturer will have a fantastic design that doesn’t turn into a big seller but could be if only they made a few changes. Even as these cars are, they might be great but for some small reason the public hasn’t noticed. If a car is great why would people not see it? This could be due to something such as mediocre engine options, or it could just be a lack of proper marketing. Either way the car languishes.

The following is a list of the top 10 most neglected models from recent years. These are vehicles that at some point were class leading, either in design, or sales, or both; some of them have just never been noticed much. Some of them are still for sale and some of them have been discontinued. All of them could be or could have been so much more if only their respective builders and designers wouldn’t have left them on the back burner for so long.

Volkswagen New Beetle

An instant hit because it had much of the charm of the original Beetle, but with none of the headaches. This was one of the first retro styled vehicles that played on people’s memories of the past, and the public loved it for all sorts of reasons. On top of the obviously nostalgic reasons, the car was actually a pretty decent little car. Roomy interior, fun to drive, good fuel economy, and the engine options available in the New Beetle over its model run have made the car even better. Not only could you get your average four cylinder engine, but you could get a peppy little DOHC turbo, or even a diesel.

Why would VW forget about this great little concept? Perhaps because it is retro. What is the natural progression of a retro styled vehicle? If you make it look like something from the past to begin with, how do you update it? Make it look like something from the more recent past? Over the years the New Beetle did receive a few minor revisions in some of the exterior bits and pieces, but from 1998 until just recently, the car has been mostly the same.

Volkswagen is not killing off the New Beetle that has languished all these years, but has in fact redesigned it for the 2012 model year. The new New Beetle is now just referred to as the Beetle. This car is quite different inside and out but it doesn’t really appear to be. The car does look pretty good for the most part and it also seems to catch a bit more of the spirit of the original beetle. Too bad Volkswagen has taken so long to make this happen. Will the masses respond well to this new take on the original car for the masses? Time will tell.
2012 VW "Bug"
Lincoln LS

This vehicle represented a completely different direction for Lincoln when it was released for the 2000 model year. Based a platform that it shared with the Jaguar S Type and the Ford Thunderbird, it was like none of the big boats that we had come to expect from Lincoln. It was available with a thoroughly modern 3.9 L DOHC V8, and rear-wheel-drive so it was a proper driver’s car. This was the first and still perhaps the only car from Lincoln that could arguably be listed in the same class as cars such as the Mercedes E class or the BMW 5 series, at least it was trying to compete with these class leaders.
The LS was a step in the right direction without any follow up.
The problem is that while this car was a great step in the right direction for Lincoln, they never did anything with it. The potential was there to make this car something that could truly compete with the European luxury brands but the LS was ignored by its manufacturer. So after selling over 50,000 units the first year, sales declined to less than 10,000 in 2006, the last year it was available. It’s no wonder the sales fell off, people got bored as the LS languished.

Chrysler 300/Dodge Charger

Same story with the Chrysler 300. Great idea, revolutionary for the builder, unlike anything else on the market when it was first released. The 300 and Charger were both playing off of names that carried some nostalgia but these cars were not really much like their namesakes. They had exciting engine options and rear-wheel-drive or all-wheel-drive. They were built to cruise in style and cruise they did, right off the showroom floor and into the possession of people who had never bought a Chrysler product before, because had not built anything like this before.
2005 Chrysler 300. Fancy and tough looking at the same time.

This car hit the market in 2005 and got trapped a few years later. Mercedes dropped the boat anchor in their stock portfolio know as Chrysler, and sold out to a capital management firm called Cerberus. Cerberus rode Chrysler into bankruptcy. After the government took control of Chrysler through the bankruptcy process, they dished most of it off to Fiat. During this time the 300 and the Charger were ignored while Chrysler was just trying to figure out a way to keep the lights on.

After Fiat got control of the reigns they looked around and realized that all of the Dodge and Chrysler models needed a refresh. So for 2011 the 300 and Charger were tweaked. They will say redesigned but tweaked is really more accurate. They got new headlights and taillights, strings of LED lights here and there, and a few extra folds in the sheet metal. The V6 option is the new and improved Pentastar power plant, but the V8 options are pretty much the same. These cars might have more life in them with this recent refresh, but they may still die an ignominious death if they get ignored again. And by the way, the 300 is actually imported from Canada not Detroit, no matter what the commercials say.
2011 Dodge Charger. Is the "redesign" enough?

Honda Ridgeline

A truck that was not like any other truck, but a truck that probably needed, or at least still needs to be perhaps a bit more like other trucks. This truck is truly unique because it actually has some of the capabilities of a traditional pickup truck but really is not built like one. The transverse mounted V6 linked to a five speed automatic is actually biased towards front-wheel drive, but can transfer power to a locking rear differential that provides a great deal of traction when the situation requires.
Not exactly a truck, but it's not exactly supposed to be.

While this truck is unique and capable in many ways, it has a few problems that show signs of its languishing. It has remained mostly unchanged since it hit the market in 2005. A few minor tweaks were implemented in 2009, and again for 2012, but these are mostly cosmetic. This truck needs something new in the powertrain department. A V8 perhaps, or at least a V6 with more power or maybe even just better fuel economy. Some of the new V6s that are on the market in similar vehicles provide more bang for the buck and much more bang for the gallon. A V6 can be just fine but it has to be able to obtain at least 20 mpg around town, and the current Ridgeline could only get that going downhill on the freeway. Honda says the Ridgeline will live on for the time being but who know how long that really is. Rumors of a complete redesign for 2013 could lead to something more worthwhile.

Honda S2000

A true driving machine! When you say “sports car” this is the car that you should think of. A small, powerful, high-revving engine that would wind to nine grand with much eagerness, with one of the snappiest 6 speed manual transmissions that was ever invented by man, directing power to the rear wheels. A convertible top that would allow you to let the wind blow through your hair as you strategically pick your way through the gears. This thing is just extremely fun to drive in every way!

Honda released this car in 1999 to commemorate the 50th anniversary of Honda Motor Company. The car was built until 2009. During that time some slight changes were made to the engine, transmission and suspension, and a few things were done to the exterior of the car as well, but overall not much changed. Some say that you need not mess with a formula such as this that works so well, but this line of thinking doesn’t account for the short attention span of people with money who buy new, frivolous cars such as this one. Some say that Honda never intended to keep this car in production and that it was only meant to be temporary. Who knows for sure? One thing is certain; wouldn’t it be better to keep people interested through continuous improvement so that we can keep a car like this in production? Seeing a good idea languish is tough.
There is a shortage of affordable sorts cars in this world, why
did this one have to die?
Nissan Titan

A big truck like Nissan had never made before. A powerful 5.6 L V8 that was modern and could put out as well as any other V8 engine in any other pickup truck. The name Titan seemed very appropriate for this manly new truck from a company that had a good reputation for building dependable trucks, but up until this point they were all little trucks.
2005 Nissan Titan. A legitimate truck.

The Titan hit the market in 2004 and just like many other vehicles in this list has been a good seller, or shown great promise, despite this the Titan was seemingly forgotten. A few years ago Nissan announced that the next generation Titan would be a rebadged Dodge Ram. Is this any way to develop an alternative pickup truck? Literally cloning the competition and putting your own name on it? Luckily this never happened, but the Titan is still there, long in the tooth and languishing. Supposedly Nissan has said that the Titan will not be killed, and that they are currently working on the replacement. This isn’t expected to hit the market until 2013 or 2014, ten years after the original hit. Can any vehicle recover from such a long model run?

Chrysler PT Cruiser

Chrysler PT Cruiser
Whether you like this little retro wagon or not, one thing is certain, it was a sales juggernaut for its first few years of production. Lines at the Chrysler dealership were out the door, full of people wanting one of these little “old fashioned” modern cars. These things were on the market from 2000 to 2010. You would think that if you had a product that was so wildly popular you would do all that you could to keep the public interested. The PT Cruiser was based largely on the Neon so development costs couldn’t have been too steep. Never the less, the PT Cruiser languished. For a few years they came out with a convertible model but that wasn’t enough to keep the model interesting.

Acura RL

Honda builds a screamingly awesome V8 engine for the Indy Car racing circuit. And in case you didn’t know, race cars with V8 engines are rear-wheel-drive. The RL has none of these things which is too bad. If Acura wants to have serious and exciting competitor in the luxury sport sedan market they need to have a V8 and a rear-wheel-drive propulsion system. The current car has a snappy V6 and a sophisticated torque vectoring AWD setup, but this is not enough for a supposed flag ship like the RL. The RL continues on selling fewer units than anything else in the Honda family, and every once in a while there are rumors of a V8 but alas, it has yet to materialize. The RL will continue to languish, and won’t last much longer without it.
2011 Acura RL, a fantastic car but it's not really enough.

Mitsubishi Galant

Forgettable, At least that's what Mitsubishi thinks.
Unbelievable that this car is still sold as new from Mitsubishi dealers. The current generation hit the market in 2004 and has not changed much since then. Past Galant models such as the old Galant GSX with AWD and a turbo from the early 90’s was a genuinely fun car to drive, kind of like a turbo eclipse but with 4 doors, or sort of like the granddaddy of the Evo. For what seems like decades now this solid sedan has languished while Mitsubishi has focused on smaller more popular cars like the Lancer and the Outlander. Most likely Mitsubishi Motors has simply been lacking the funds necessary for some R&D of a new Galant, but the thing that is hard to understand is that they will be releasing the new i electric car sometime next year. That couldn’t have been cheap to design and build, so they must not be totally out cash yet.

Ford Ranger

This little truck has been around for a very long time and during its existence it has been a good seller in the compact pickup market for Ford. Over the past 10 or 15 years this segment of the auto market has changed. None of the domestics have been able to move many of their little trucks for some reason. The Japanese have maintained sales pretty well based on the reputations that they have built for putting out a solid product, the lack of sales has cause the domestic small trucks to languish.

The Ranger first hit the market in 1983 after ford decided to bring their compact pickup model in house. The Ford Courier that preceded the Ranger as Ford’s little truck had been built by Mazda. The Ranger was a good seller from the beginning and Ford at least tried to keep the truck somewhat fresh. The current model has remained mostly unchanged since 1998, and is scheduled to be discontinued in December of 2011. That means that this truck has been around in its current form for 13 years. But wait there’s more! The changes to the truck in 1998 were mostly cosmetic and in reality the truck has actually been mostly the same since 1993. In reality you could find many similarities in the base design of the first 1983 Ranger and the last 2011 Ranger; this little truck at no point received a full and complete redesign. If it were not for fleet sales, Ford probably would not have sold any Rangers for the last seven or eight years.
The ho-hum Ford Ranger
In all likelihood the Ranger will be back at some point, especially if gas prices go back up and people decide that they want more small truck options. Rumors abound concerning the matter, and in foreign markets Ford sells a completely different Ranger that is much more modern than the one that is about to die. This global Ranger could be the one that we see here in the U.S. in a few years. Why did Ford ever let the Ranger languish to begin with? Why does any company ignore or forget a good idea?
The Global Ranger that we can't buy here in the U.S. at least not yet.

Sunday, October 30, 2011

Engine Efficiency #3

The third and perhaps the most important efficiency related to engine performance and affecting overall engine output is volumetric efficiency. This is essentially a measure of how easily the engine breathes air in and out. The more air that can be moved into the engine, the more oxygen there will be to mix with more fuel. This creates a more powerful combustion event whenever more power is needed. The power is in the fuel. If you can burn more fuel you can create more power. The actual rating of volumetric efficiency is the measurement of air that actually makes it into the cylinder while the intake valve is open, and the piston is moving down, expressed as a percentage of the theoretical potential volume of the cylinder.

To understand volumetric efficiency it must first be understood that the piston moving down on the intake stroke, with the intake valve open, only creates a negative pressure within the cylinder; it does not suck the air in as you might believe. Once negative pressure, or vacuum, is created in the cylinder, a greater force can push the air into the cylinder. That force that is atmospheric pressure. This is the primary reason that if you drive your car over a high mountain pass, where atmospheric pressure is low, the car always seems to have less power than it does when you are driving around town. Oxygen density at high elevation is also diminished. Sorry, Denver and Salt Lake, but cars are always faster in Los Angeles or Houston.
So if atmospheric pressure pushes the air into the cylinders, it will have to push past obstacles that are in the intake manifold, to get as much air in as possible before the intake valve closes. Not too many engines can get a full dose of air into the cylinder, but the more air that can get in there, the greater the volumetric efficiency.

Equally important as breathing air in is the ability of the engine to easily push the exhaust out. If all of the exhaust is not evacuated from the cylinder then it will displace some of the incoming oxygen. A well designed exhaust system will not only allow easy removal of exhaust gases from the combustion chamber but it can actually aid in drawing the air/fuel mixture into the cylinder. After the piston moves to the top to push exhaust out of the cylinder, and before the exhaust valve closes completely, the intake valve will start to open. The air/fuel mixture will then begin to move into the combustion chamber. Ideally this burst of air from the opening intake valve will help to move the last bit of exhaust out of the combustion chamber. This is a condition known as scavenging, and the better the scavenging the more the inert, exhaust gasses can be removed and the more space there will be for the fresh air/fuel mixture.
Exhaust manifold with tuned

Other than more precise fuel control, improvements in volumetric efficiency represent the biggest difference between old engine designs and those found in the modern day automobile. Better intake manifold and exhaust manifold designs help the air to flow in and out much more effectively. These manifolds use what is called tuned ports in order to make this happen. A tuned port intake manifold is designed so that all of the tubes or passages that carry intake air to ports in the cylinder head are exactly the same length. The length will also be designed according to the way pressure waves in the manifold resonate back and forth as intake valves open and close. These tuned ports take advantage of a phenomenon known as Hemholtz resonance.
As the air is being pushed into the engine through one of the passages in the intake manifold, it will suddenly stop every time the intake valve at the end of that runner slams shut. The momentum of this air will actually cause the air to reverse direction as it now kind of bounces off the closed intake valve. This pressure wave will move back into the plenum where is serves to help push air into the other runners in the manifold. If the ports are all the same length, then just when the intake valve in the first port opens again, another pressure wave coming from another port in the manifold will be timed just right to help push the next charge of air through the open intake valve into the combustion chamber. This is where that scavenging effect comes into play.
A dramatic example of an engine with a tuned port intake manifold.
Because Hemholtz resonance only occurs at specific engine speeds and loads, many engines also have what is called a variable length intake manifold (VLIM). This is a manifold that can change the length of the intake runners while the engine is running, in order maximize air flow for various operating conditions. At low speeds a longer narrower intake helps to increase the velocity of the incoming air, this increased velocity helps to fill the cylinder with air when the engine is running slowly, and the negative pressure in the cylinder doesn't build as quickly. This gives better throttle response off the line because of the increased torque that can be provided.
The inside of a variable intake manifold. Notice the butterfly
valves that can close to redirect intake air to other passages.

At high engine speeds a series of valves within the intake manifold will simultaneously switch the intake air to a much short runner that is wider. At high speeds the negative pressure in the cylinder builds quickly and in order to fill the cylinder we just need a short, wide path for the intake air. Race cars and other high performance vehicles have very short wide intake runners in the manifold because they are meant to run almost exclusively at high speeds.

Another very significant improvement in engine design that increases volumetric efficiency is the size and number of valves. Since the valves are the gateways in and out of the combustion chamber this of course makes sense. In the old days the combustion chamber had one intake valve and one exhaust valve. These valves were mounted in the cylinder head right next to each other, facing the top of the piston. In the old old old days they were mounted in the block but we won’t go back that far. These valves and the ports that they seal, can be made bigger which allows more air in and out. The problem is that they can only be made so big before the ports start to touch in the center of the combustion chamber. In order to provide even more flow, extra valves are added to the cylinder.
A newer valve arrangement referred to as a pent-roof hemi.
Intake and exhaust valves are set opposite of each other. The
spark plug hole being right in the middle of the combustion
chamber also provides benefits.

An old style wedge combustion chamber. The air does not flow
in and out efficeintly, and there is no room to make the valves any bigger.
Some manufacturers started building engines with two intake valve and one exhaust valve, or two intake valves and two exhaust valves. Some even made engines with three intake valves and two exhaust valves. In order to fit all of these valves in the combustion chamber the arrangement had to be changed. Instead of the valves being arranged next to each other, facing the same direction in the combustion chamber, the valves are mounted on opposite sides of the combustion chamber with the valve faces being angled towards each other. This angled arrangement also increases volumetric efficiency because it provides more of a straight path for the air, through the combustion chamber.

All of these valves crammed into the cylinder head would be difficult to operate with a cam-in-block design that was the standard. For this reason and others related to mechanical efficiency, the cam was moved out of the block and put in the top of the head. In some instances two cams are used to allow the valves to be bigger and angled more towards each other in the combustion chamber. These designs that use two cams in each head are referred to as dual overhead cam, and they are used on all of the most modern high-performance engines. A DOHC engine with a straight cylinder arrangement has two cams, an engine with a V arrangement, or a boxer engine with a flat arrangement has 4 cams.

Cam timing or phasing, and systems that can manipulate this during engine operation, have become a major contributor to increased volumetric efficiency. One of the challenges to making an engine operate efficiently and return good fuel economy, while maximizing power, and burning the fuel as cleanly as possible, is the fact that the engines must operate under a wide range of speeds and loads. An engine can very easily be made to run well at a specific load or RPM range. This is why stationary engines used in industrial equipment such as generators and pumps are usually among the most efficient. They really only operate at one speed and under a very similar load condition each time they are used.
This cam sprocket has five vanes that can move when
acted upon by pressurized oil to change the phasing
between the hub of the sprocket and the teeth
Changing the cam timing will change the timing of the opening and closing of the intake and exhaust valves. Considering that atmospheric pressure is ultimately responsible for pushing the air into an engine, in order to maximize volumetric efficiency at high RPMs, the intake valves must open sooner than they would at low RPMs. This can be done by changing the cam phase. The cam is essentially rotated a few degrees one way or the other in accordance to where the crankshaft is in its normal rotation. This feature is usually referred to as variable cam timing. Ford calls there system TiVCT, Toyota calls their system VVTi, Honda calls their system iVTEC, and so on (What is the deal with the lower case “i” anyway; marketing people everywhere like using it). All of these systems do essentially the same thing. The VTEC system from Honda also incorporates a system that can change how much a valve opens. This doesn’t necessarily change cam phasing but it does cause a sizable increase in volumetric efficiency.

The most fun and perhaps most dramatic way to increase volumetric efficiency is through forced induction. Using a device such as a turbocharger or a supercharger, volumetric efficiency can be literally pushed to over 100%. In a naturally aspirated engine some form of vacuum nearly always exists in the intake manifold and atmospheric pressure rushes in to fill the void. In an engine that uses forced induction the intake manifold is pressurized to anywhere from just a few psi to a few dozen psi. This causes even more air or oxygen to move into the cylinder which allows the engine to burn even more fuel. This might seem like it would cause a decrease in fuel economy and in some extreme applications it does. In reality however, it allows a vehicle to use a much smaller more fuel efficient engine because the forced induction can make the engine more powerful only when more power is need such as during acceleration or passing. The rest of the time all that extra power is not needed. On a normal flat road a Geo Metro can go 65 mph just as easily as a Corvette.
A turbo charger is just an air compressor that pushes air
into the intake manifold.
Turbochargers and superchargers have a drawback in that they increase the load on the engine. Superchargers affect the mechanical resistance that the engine has to deal with because they are driven by a belt off of the crankshaft. Turbochargers are driven by the exiting exhaust gases in the exhaust pipe. This makes it more difficult for exhaust to leave the engine. Both of these drawbacks are minor compared to what is gained in the overall breathability of the induction system.

So what does all of this have to do with engine design that was referenced in the first efficiency article? An engine that is to be used in a mid-size sedan may be the same engine that is used in a mid-size SUV. Because the SUV weighs more or because it might have to tow a trailer once in a while, the way the engine reacts under these different situations is going to make a difference in the overall drivability of the vehicle. The larger vehicle will need more torque at lower RPM than the smaller vehicle. Changing the arrangement of the intake manifold runners, or the way the variable cam timing functions will change the way the engine responds. The engine in the sedan may need to rev higher so things that cause internal resistance affecting mechanical efficiency may need to be considered.

The one thing that is constant is that the engines that perform the best are the ones that rate well for mechanical efficiency, thermal efficiency, and volumetric efficiency. This doesn’t mean that an engine with good ratings in all three of these categories is going to have the highest output; it may get the best fuel economy or perhaps the lowest emissions instead. Ideally it would have some combination of the three. Beyond gas mileage, power, and emissions, what else matters?