Thursday, April 19, 2012

Shed Some Light

Looking on the Bright Side

You are driving your car down a lonely country road at 11:00 pm. The road is winding back and forth but you cruise along at a comfortable and steady 45 mph. You probably have the stereo on playing some personal selection from your iPod, or perhaps you are listening to some off the wall talk radio show about aliens from outer space. Either way your drive is no problem. Even when a deer jumps out in front of you, the animal is easy to spot, so you just slow down a little and the thing gets out of the way.

The thing that makes this leisurely drive possible is the headlights of your car. These lights are usually taken for granted despite the fact that without them your car becomes completely useless literally half of the time. Imagine making the same drive with no headlights. How long would you be able to drive before your car is in the ditch? With these two simple electrical devices on the front of your car you can see just about everything that you need to in order to keep the situation under control.
Headlights are almost as old as the automobile itself. They were applied to some of the very first cars in the form of kerosene burning lamps. Over the years headlights have changed substantially but on the other hand they have stayed the same. They always come in pairs and they are always in about the same place on the front of the car. They have high beam and low beam modes in which they operate, and they actually add something to the overall looks of the exterior of the vehicle in a way that not many other features do.

Let’s have a look at some of the different headlight designs, and some other features that are becoming more and more common each year.

Sealed Beam

These are the old style headlights that were essentially the same from the 1930’s to the 1970’s. The filament is tungsten like most other bulbs, and in later sealed beam head lights the filament was surrounded by halogen gas to make the light brighter, and help the filament last longer.
Seal beam headlamps

These headlights incorporate the filament, reflector, lens, and housing all into one unit. Some of them have the high beam and low beam filaments together in the same housing as well. This means that the entire assembly must be changed if the filament burns out. The angle of the beam is adjusted by moving the position of the entire assembly.

These lights are cheap to replace even if everything is combined into one unit because for years and years the design of the seal beam headlight didn’t change. They were all round pretty much from the time they were invented until engineers at GM came up with the revolutionary idea of making them square. Once the square ones caught on then all of them were square. Considering all of the many different designs that were found on various makes and models between the 1930’s and the 1980’s, it’s funny to think that the headlight shape hardly changed at all.

Composite Halogen

The composite headlamps that are found on 90% of cars today use a halogen bulb similar to the sealed beam headlights, except the lens, reflector, and housing are a separate assembly from the bulb. This means that the bulb alone gets replaced when it burns out. This is also the reason that so many different headlight designs exist today. These separate bulbs are easy to replace, and only a few different bulb designs can suit the needs of the many different shapes and styles headlight assemblies.
Composite headlight assembly.

The bulbs are just halogen bulbs but the reflectors vary substantially. Some halogen bulbs use a projector beam reflector and lens to concentrate the light from the bulb. These are the headlights that actually appear to have a small, dark, round lens behind the main outer lens when the headlights are not on. Sometimes these are confused with HID headlights but they are not the same. HID or Xenon headlights are explained below.

The bulbs in the composite headlight assemblies are easy to replace but caution should be taken when servicing these bulbs. If you touch the glass part of a halogen bulb, the bulb will burn out very easily. Oils from your skin, no matter how clean your hands are, will cause the glass the get even hotter than it already does under normal circumstances. This will actually melt the glass and cause the bulb to pop.

Sometimes the regular halogen bulbs that are car uses are not bright enough. The aftermarket has a few products that can actually make the headlights brighter. One of them is the Sylvania Silver Star bulbs. These bulbs are not cheap considering that a pair of them will set you back about $50. They are very bright and will help you to see better at night.
Two headlights are shining on this door form the same vehicle. The one
on the right is a conventional halogen bulb and the one on the left is a Sylvania
Silver Star halogen bulb. This is not a paid endorsement but a photo actually
taken by the author of this article.


These are those headlights that appear different than other headlights when you see them from a distance. They will usually have a blue tint to them that is bluer, the farther away the vehicle is. As the car gets closer the light becomes whiter. These lights will always use a projector beam reflector and lens to direct the light from the bulb.

An HID headlight. The one on the left is the HID used for low beam. The one on the right is halogen used for
high beam. This configuration is sometimes referred to a bi-xenon.

The bulb does not contain a filament like the sealed beam or the halogen bulbs. The HID bulbs actually produce light by arcing electricity from one electrode to another within the bulb. The light is literally emanating from the electric arc rather than from a glowing piece of wire. In order to make this work a ballast is used to step up the 12 volts from the vehicle’s electrical system to a level high enough to make the jump. These types of bulbs take a second to actually come on because it takes a moment to build the necessary voltage within the ballast. An igniter is used to make the initial ionization of the air molecules between the electrodes in the bulb. Once the arc has jumped the ballast provides the increased voltage to maintain the arc. The bulb is filled with xenon gas that helps the arc to be even brighter. These bulbs are about $200 to $300 a piece, but they last much longer than a regular halogen bulb.

HID headlights are somewhat controversial because they are brighter than halogen bulbs. Some people complain that when they approach another car with HID headlights, they are blinded by the extra brightness coming from these lights. Because of this many vehicle with HID’s will have a self-leveling mechanism that corrects the angle of the reflector when needed. If something heavy is placed in the trunk, or if you are hauling around your 300 pound sister, the back end of the car will sag. This makes the headlights tilt up which makes the headlights more blinding to oncoming traffic no matter what kind of headlights you have. Most HID headlights will have a sensor that can determines when the headlights are not level or pointing in an upward direction and a small motor will activate to tilt them back down.
Fake xenon lights are lame.

A very popular thing right now is fake xenon lights. These are halogen bulbs that are tinted blue and give off blue light to simulate HID’s. Many times the package will call them HID or xenon, but they are not. These bulbs can be spotted easily because they appear blue but are not really all that bright. They also appear blue from a distance but don’t turn white as you get close to them. These bulbs are for the silly kids that like to think they’re cool.

Light Emitting Diodes

Of all lights sources that exist in this world, the one that is quickly becoming more common in every area of lighting is the light emitting diode (LED). Everything from flash lights, to TV screens, are now using LED’s instead of incandescent or other types of bulbs. The biggest reason for this is that LED’s use a tiny amount of energy compared to standard bulbs, and they last much longer. LED bulbs also don’t suffer from a decrease in output and intensity over time, in the way that incandescent bulbs do.
LED headlights on a Lexus LS600h.

LED bulbs are very efficient because more of the energy that they use gets converted to light rather than getting converted to heat. Standard incandescent bulbs and halogen bulbs can produce a lot of light but they actually produce more heat than anything else.

Because LED bulbs are the latest, they are also the most expensive. Like everything else the cost will come down with a little time. Right now only the most high-end luxury or sports cars have them. People who buy these cars are usually willing to pay anything for a gadget that nobody else has.

Other Headlight Features

Some other headlight features are becoming more common. Most of these things are made possible by the fact that headlights are now computer controlled on most vehicles, in some way or another. Putting computers in charge facilitates many features that people come to rely on, and eventually cannot do without.

Headlight Washer Systems

In Europe, automotive lighting standards dictate that any vehicle with headlights that discharge a high level of lumens must have a system for washing the headlights. This system will consist of wiper arms that look like tiny windshield wipers, and/or a system that sprays the headlights with washer fluid. These sprayers might be hidden and only pop up to spray the lights. These light washer systems are meant to clean the headlights which in turn reduces glare from the headlights when viewed by drivers in other cars approaching at night.
Headlight wiper on a euro spec Mercedes.
In the U.S. such headlight washing systems are not required but are permitted. Because of this many European cars and few Asian cars sold in the U.S. may have these systems. Since manufacturers put these systems on models sold in Europe, they don’t bother to remove them from the U.S. versions.

To activate the headlight washer, the driver can usually just clean the windshield with the headlights turned on, and the headlights will be washed as well.

Automatic Dimming

Automatic headlights, the kind that can turn themselves on and off, are very common on cars and trucks today. These have been around for some time, but new ways to automate headlights are now starting to appear. Things such as automatic headlight dimming are now common on most high-end cars. This feature is not just there to switch between high beam and low beam, it actually requires some processing to determine how the lights should be controlled and when.

A digital camera is found somewhere in the front of the car to face forward and look at any light in the distance as the car is moving down the road. The computer uses these images to determine if the light ahead of the car is light from another vehicle, such as headlights or tail lights, or if it is something like a street light. If the light is determined to be coming from another vehicle then computer will determine how far away the light is.
camera on the rear view mirror for automatic dimming.
The computer uses high-side drivers to feed power to the headlights at a varying duty cycle to control the brightness of the lights. This means that the computer turns the headlights off and on so fast that you can’t see them flicker, however, the longer they are on the brighter they appear, and the shorter the time they are on the dimmer they appear. So rather than just having high beams and low beams, the brightness of the headlights is infinitely variable within a given range. Maximum brightness when no other cars are around, rather dim when other cars are close, and somewhere in the middle when cars are ahead but maybe a little ways off.

Cornering Lights

Cornering lights have traditionally been the lights that are located on the sides of the front corners of the car, and come on when turn signals are turned on while the headlights are on. The light shines to the side of the car helping to illuminate the turn. Some of these systems still exist but cornering lights are generally much different today. They still help drivers to see better in a turn but now the cornering lights use a system that actually rotates the bulb and the reflector in the headlight assembly as the car goes through a turn.

The computer that controls this system is watching a steering angle sensor that’s attached to the steering column. As the wheel is turned while the headlights are on, the computer activates small actuators in the reflector assembly to steer the lights in the direction that the wheel are turning. This system shares some components with the automatic leveling system that was discussed previously.

Driving/Fog Lights

Real fog lights are yellow.
Fog lights are yellow, driving lights are not. Most cars that have extra lights lighting a path for the vehicle, other than the regular headlights, have driving lights. Driving lights are white, the same color as the headlights. These are just meant to provide extra light on the front of the vehicle and are not intended to be used alone, or in conjunction with the marker lights only.

Fog lights are yellow and always mounted very low on the front of the vehicle. Yellow light will not reflect off of fog, or falling snow and it makes driving in such conditions much easier. Driving in a blizzard or heavy fog at night can be especially nerve racking but real fog lights make a difference that is amazing. Most real fog lights are after market since auto manufacturers don’t install yellow lights on their cars from the factory.

Shed Some Light

Take care of your headlights. Nothing is worse than driving a car at night that has headlight problems. Keep them clean and properly aimed. Also, remember that your headlights really can be a problem for other drivers. Don’t drive with your brights on in city limits, if you have a lifted 4X4, make sure to adjust your headlights accordingly. Good headlights help you and help other drivers, especially on the winding canyon road in the middle of the night.

Saturday, April 7, 2012

Gas Savers and Hot Air

Want to save some gas? There’s a sucker born every minute!

When gas prices climb, the crazy people and swindlers come out of the word work. Since we are well on our way towards gas prices going above four dollars a gallon all across the country and not just on the coasts, consumers are grasping at straws. They are doing anything they can to try and save fuel including spending money on contraptions that come with big promises. Many cheats, thieves, and charlatans are pushing all sorts of products to try and tell you that you can save fuel by installing their revolutionary device.

Most of these devices are either doing something to change airflow into the engine, or they are doing something to try and affect the combustion process, or they try to enhance the ignition source. The devices that change the airflow into the engine probably end up blocking the flow of air into the engine more than anything else. This will actually lead to a loss in power and possibly a decrease in fuel economy. The gadgets that claim to affect combustion probably don’t do anything at all to the combustion process, and in some cases might even be harmful to some of the things that make the vehicle run right, such as O2 sensors. If the device adds any kind of fluid to the air fuel mixture it is possible to hurt the O2 sensors which are installed in the exhaust pipes.

They all claim an increase in fuel economy somewhere around 20 to 30 percent. The problem with this is that modern engine control systems are so accurate and so efficient that only a tiny fraction of the fuel that is injected doesn’t get consumed. When fuel is not fully burned in the combustion chamber it comes out the exhaust as carbon monoxide and hydrocarbons. Looking at the emissions from a modern vehicle, before the catalytic converter, the amount of CO and HC’s is very low. CO is likely to be less than .009% and HC levels will be less than 1 part per million. How on earth can it be possible to increase your car’s fuel economy by 20% by burning this unburned fuel, when we are only talking about the possibility of burning such a tiny amount?

Most of these devices take a theory that applies to something else in the engine function or controls, and misapplies that theory in the name of saving fuel. The following is a bit of information about a few of these devices from different manufacturers. These are not necessarily the most popular ones but they are representative of the different types of devices that the consumer can waste their money on in a bout of wishful thinking.

Tornado Fuel Saver

This is a little device made from small metal fins arranged together in a circle that are supposed to create a swirling motion in the intake air. One of these contraptions will usually cost you about $50. This swirling motion is supposed to increase volumetric efficiency or something like that. The fact of the matter is that most engine designs and intake manifold setups are already designed to create turbulence or a swirling motion in the air stream that enters each cylinder. This helps to atomize the fuel as it leaves the injectors and flows into the combustion chamber, and it is supposed to help the fuel mixture fill the combustion chamber evenly so that it gets burned more thoroughly.

The Tornado installed
Swirling the air as it enters the intake manifold is useless since the air splits into the various intake ports as it goes into the engine and how is it supposed to keep this swirl? Automotive engineers have been studying air flow and volumetric efficiency for over a hundred years now and they know what works and doesn’t work when it comes to making the air behave properly in the intake manifolds and the combustion chamber. If efficiency could be increased so easily every engine designer and manufacturer would immediately be integrating their own version of this design or process into their product, and if they didn’t it’s very likely that the EPA would mandate that they do so. This notion really applies to all of the gas saver devices.

Platinum Gas Saver

This item will set you back about $150 plus installation. Many companies build something along these lines; they are all about the same thing. Manufacturers claim that it might take 1,500 miles before it starts to become effective. This is another common claim from the people that make just about every fuel saver. They also claim that you might need to replace your oxygen sensors. This is silly because no good reason exists for doing so just because you are now running tiny amounts of platinum through your engine. The real reason that they recommend this is because most O2 sensors on cars that have been on the road for a while, sat for 100k miles or so, probably have O2 sensors that have lost some efficiency anyway.
Magic platinum fluid. If the solution in the bottle really is platinum, it can't be cheap.

Any gas saver that uses platinum has some kind of reservoir where a solution is held that contains some form platinum. A vacuum line from the engine’s intake manifold connects to the reservoir where the solution is sucked into the intake manifold. Once inside the manifold it goes into the combustion chambers of the engine, or at least into the combustion chamber that is closest to the vacuum line.

The theory is that when combustion takes place in the presence of platinum, the combustion will be more complete. Platinum is one of the elements found in catalytic converters to act as a catalyst to trigger the complete oxidation of any of the carbon monoxide and hydrocarbons that didn’t get used up in the combustion process. The definition of a catalyst is something that triggers a chemical reaction but does not get consumed in the process. Dribbling platinum into the intake manifold and then letting it run down into the combustion chamber is not the same as coating a ceramic element inside of a catalytic converter. This does nothing to save fuel.

Fuel Doctor

This device retails for $50 and is super easy to install because you just have to plug it in to your cigarette lighter or accessory socket. The device has a couple of LEDs that light up as you drive down the road. The manufacturer claims that this electronic device cleans and conditions the electrical power running through the vehicle’s electrical and electronic systems as you drive. With this “conditioned” electricity the electronic control systems become more efficient which helps the engine become more efficient and thus use less fuel.

This is pure quackery and very insulting that these people think we should believe this drivel! Conditioning the electrical power? What nonsense! How is the condition of the electricity affecting engine output, and how would something plugged into the power outlet change the electricity flowing throughout all of the vehicles systems?

On their website they show a video of a power supply attached to an oscilloscope and on the scope you can see some electrical noise. They say that this noise represents the noise from the battery of the car. The problem is that a DC battery doesn’t put out any noise, not even on a car that is 2 years old or older. This is just not true, and combined with the fact that when your engine is running the system voltage comes from the alternator, their demonstration is useless. Some noise can occur from the alternator but it doesn’t have the effect on the computers and control systems that these people claim.

With the alternator turning typical electrical system voltage is going to be in the neighborhood of 13.5 to 14.5 volts. The voltage must be higher than the 12.6 volts of the battery so that electrons will flow into the battery recharging it. The alternator actually produces 3 phase A/C electricity but everything in the car runs off of D/C, and of course the battery can only store D/C. Because of this the electricity produced by the alternator must be rectified from A/C to D/C.

This occurs in a device called the rectifier bridge which is made up of six diodes, 2 for every phase of alternator output. What actually occurs during the rectification process is the alternating current that switches from positive to negative gets cut off from going negative. These negative waves get rerouted and become positive. This happens to all three output phases so that the end result is a fairly direct flow of current into the vehicle’s electrical system.

Looking at this output up close using an A/C coupled oscilloscope you can see a bit of what is termed A/C ripple. If there is too much A/C ripple then things like the engine control module can be damaged. The maximum amount of ripple that the system can have before problems start is about 500 mV peak to peak, high to low.
Normal A/C ripple. This is harmless and normal on every car. This is the top of
the A/C sign waves that come from the alternator.

On the video that the Fuel Doctor shows on their website they show some noise that could be compared to A/C ripple, then they plug in their device and the noise goes away. Big deal. The noise to begin with appears to be around 100 mV. So even if this was true A/C ripple from an alternator, or some other such electrical noise, which it is not, the oscillation that they say is a problem isn’t even high enough to affect anything.

These computers are digital devices. They are either on or off, they either work or they don’t. The A/C ripple will cause them to shut down, or it won’t. Middle ground or gray area is not something that occurs with the function of a digital control mechanism.

Like so many of the other fuel saving devices, the Fuel Doctor people say that you have to drive your vehicle for a while before it will work, but they don’t really say why. Probably to blow out all of the carbon or some such thing. The real reason that they say this is because the device won’t work ever, but if you keep trying then I suppose you hang on to the hope that you really didn’t waste your money, or maybe with some time you will become bad at math and will not be able to properly calculate fuel economy.

Ignition Enhancers

These devices usually claim that they can save you gas by increasing the power of the spark that is responsible for igniting the air/fuel mixture. The claims vary and the setup of these devices follow a few different arrangements. Some of them are meant to be attached to the spark plug wires, and some consist of special voltage enhancer that installs in series with the coil wire. This thing is just another air gap for the spark to jump.

Those that claim to increase the voltage say that more voltage in the secondary ignition means that the fuel will burn faster, or more efficiently. This does not happen because the controlled burn of the air/fuel mixture occurs once it is lit, and the voltage of the spark does not affect the rate of combustion. The only thing that’s important is that the duration of the spark be long enough to get a good burn. Spark duration will usually go down if the firing voltage in the secondary goes up.
Clip these ionizers (little rubber blocks) to your spark plug wires and you too
can save save save!

In many high performance applications increasing this voltage is necessary because these engines have higher compression ratios which makes ionization of the air molecules in the spark plug gap more difficult with lower voltage. In these cases a more powerful ignition coil is used, and/or higher voltage is used in the primary side of the ignition coil in order to produce higher voltage in the secondary.

Increasing the secondary voltage only helps in special applications, and really does nothing to help any situation on the average vehicle of today, and most especially does not save you any fuel. Increasing the secondary voltage can have a slightly negative effect in that it can cause spark plugs to wear faster than normal. This extra voltage causes more metal transfer between the electrodes of the plug which is how spark plugs wear out. The other thing that can happen is that as resistance increases in secondary ignition components, the increased voltage will make it more likely that the spark will leave its normal path. This will cause a cylinder to misfire.

Fuel Line Magnets

These have been around for a very long time and come with all sorts of different names printed on the package. Sometimes these devices are referred to by their manufacturer as a fuel ionizer. This is usually the case when they want the buyer to think that they are getting something special, something that is not just a couple of magnets. An ionizer sounds like something high-tech. An ion is simply an atom that is missing an electron or has and extra electron. What does this have to do with combustion? Nothing.
Fuel line magnets in action.

They all work (don’t work) the same way. You attach them around your fuel line that is going to the fuel rail where the injectors are located. This allows the magnetic flux that emanates from the magnets to affect the fuel as it flows to the injectors. Much of the time these fuel lines are metal so attaching magnets to it wouldn’t even allow the field to reach the fuel since the metal line would actually deflect the magnetic lines of flux.

The claims all vary from one magnet maker to the next. Some claim that the hydrocarbon molecules that make up the fuel are grouped in big clusters that when injected don’t get consumed all of the way. This leads to inefficiency, more fuel used, less power output, and higher emissions from the tailpipe. Some others claim that the molecules are strewn about haphazardly as they enter the injectors which causes inefficiency in the burn. Passing through the magnets forces the molecules to line up in nice even rows, facing the same direction. Aligning molecules has nothing to do with combustion efficiency. Furthermore, if aligning molecules somehow did contribute to combustion efficiency, how would you keep the molecules aligned after they passed through the magnetic flux? Everyone knows that molecules are always moving around bumping into each other even when they are just sitting there.
You can tell that they work well based on this picture.

So the magnets are supposed to rearrange the molecules, which then causes the fuel to burn faster, or more completely. No matter what the claim is about the hydrocarbon molecules and how they are behaving or not behaving, the fact of the matter is that magnets or fluxes don’t have any effect on gasoline. Magnets only affect things that are electrical, or at least somewhat ferrous, like iron or steel. Everyone knows what magnets stick to and what they don’t stick to, but never the less people buy into the supposed power of magnets and claim that they work miracles for all sorts of different things.

Hydrogen Generators

If anything has a chance to work it this, but sadly it still falls short. These devices tout the use of hydrogen (H2), or Oxyhydrogen (HHO), as being something that can be mixed with your intake air to increase your fuel economy. This may be true in theory and this is why many people who don’t believe in any of the previously mentioned fuel savers will continue to come back to these devices as being legitimate. The problem here is a matter of scale.
A typical HHO generator.

Engineers have developed a number of different alternative fuel prototypes that run on hydrogen. Most of them use hydrogen fuel cells which use the single proton and the single electron of the hydrogen atom to produce electricity that runs an electric motor. This is totally unlike using hydrogen to produce combustion. Some auto companies however, have built vehicles with normal internal combustion engines that will run on straight hydrogen instead of gasoline. These engines work very well and produce very little pollution, much less than an internal combustion engine because there is no carbon in any form getting wrapped up in the combustion process.

In these engines a large volume of hydrogen is stored in a very large and rather specialized tank onboard the vehicle. While these vehicles work very well the problem they have is the process of sourcing the fuel. While hydrogen is the most abundant element in the universe it does not occur naturally anywhere on planet earth, so it is usually rendered from splitting water molecules or breaking down hydrocarbon fuels. This process takes a tremendous amount of electricity.
Hydrogen fuel saver mounted under the hood.

The hydrogen generator type fuel savers use a very small fuel cell in which electrolysis is used to split the water molecules that are stored in a small onboard tank. The hydrogen that results is drawn into the intake manifold, and it does get burned with the gasoline. The total amount of hydrogen that is used is tiny, certainly not enough to make a difference in fuel consumption. If you were to install more fuel cells to produce more hydrogen then you would have to have more electricity coming from the vehicle’s alternator to produce the extra hydrogen. This would place an extra load on the alternator and on the vehicle’s engine. If the engine is working harder, then obviously it would be using more fuel.

Someday maybe we will have cars that run on hydrogen in some way or another, but that day will not come until we figure out a way to produce massive amounts of electricity in a manner that is relatively cheap and does not pollute. Which is not to say that we couldn’t do this now.

When Will We Learn?

If you want to save fuel get a smaller car. Many people insist on driving cars that are bigger than they need or have bigger engines then they need. If they want to drive this kind of car then that’s fine, but they shouldn’t expect to have 300 horsepower and 40 mpg. Other things that can help save fuel are simple things like obeying speed limits, and avoiding jack rabbit starts every time the light turns green. Most cars will also get better fuel economy if speed limits are obeyed.

Vehicle maintenance also helps to save fuel. If your check engine light is on, get it fixed because there is a good chance that the failure will cause a reduction in fuel economy, because it most certainly causes an increase in emissions. Remember simple things like replacing spark plugs at recommended intervals, and keeping all services current. These things are not difficult to remember, all you have to do is follow the manufacturers recommended service schedule. This can always be found in the owner’s manual or through some searching online.

What about tire pressure? Some politicians in Washington like to tell us that we should just check our tire pressure every time the price of gas starts to jump up. Does this really make a difference? It does make a difference but it is pretty slight. Somewhere in the neighborhood of .03% for every PSI that you are low. This adds up eventually but keeping your tires inflated properly is more about making sure they don’t wear out too quickly, or about keeping the car safe, then it is about fuel economy.

So if you want to save money at the pumps the most important things are: drive a smaller car, drive with a little more self-control, and take care of your car. Whatever you do, don’t buy any crazy device to hook up to your engine, or to plug in here or there. None of these work because if they did, everyone would have them.