Anyone Can Be A Parts Hanger

The term “parts hanger” is commonly used among automotive technicians to describe someone who has no idea how to diagnose a car, but has enough tools and knowledge to be dangerous and can certainly replace broken parts. The fact of the matter is that most of the people who make a living working on cars are parts hangers more than they are technicians.

The automotive repair industry has no standards. This is a problem from top to bottom. Anyone can open a shop, anyone can sell service, and anyone can perform the service. It would seem that the only requirement is that you have your name on your shirt. Because the bosses don’t care about standards they hire parts hangers instead of technicians. What they need and perhaps what they want are technicians, but they may not have a choice but to hire are parts hangers.

Would you go to a doctor that was not board certified to practice medicine? What if he said he had all the tools and lots of experience? What if he said he could save you lots of money, you just had to trust him? You might say that this analogy is silly because doctors deal with life or death situations. Many medical procedures are not such dire situations but we would still never trust anyone who was not a certified doctor. If someone replaces the brakes on your car improperly we are talking life or death. If your car breaks down in a blizzard on some lonely road because of an incompetent mechanic we are again talking life or death, so I think the analogy stands.

The thing that must change is that technicians need to seek more and better education both before they enter the auto repair industry, and after they are already working in a shop. Education must continue because the advancement of technology never ceases. As time goes by this technological growth is exponential, and the need for frequent training becomes even more important.

Most shops provide very little opportunity for such training because they are too busy just trying to run their businesses, and honestly most of their technicians really don’t think about it much anyway. The bosses figure that they themselves don’t need any new training, so why would their technicians? As long as this is the way things work the quality of the diagnosis and repair work the customers are paying for will continue to go down.

What is the public to do? Not much. Once the public demands better service by only going to shops with better educated technicians, then things might change. The people who are tired of settling for mediocre service and shoddy workmanship can take a stand by going somewhere else and demanding that only the best technicians work on their cars. They could at least ask whether or not the technicians get to attend any kind of professional development training to make sure they are up on all the latest and greatest technologies.

The standard must be set by the customers. Businesses that do not respond to customer demands are businesses that go away. Some people will always look for the cheapest service without regard for anything else, but these people never really spend the kind of money they should to maintain their cars, so the budget shops that only they would frequent would still go away.

The automotive world needs parts hangers. We need people who can change our oil and mount and balance tires. These are jobs that don’t require great skill and if we have unskilled people doing these things for us it does keep the cost down. Those that work in these positions will never make much money and maybe that’s just fine. Everyone needs to find employment somewhere, and those that are really sharp can start in these positions and easily work their way up.

However, when it come to diagnosing complex computer control systems that manage everything on the vehicle from fuel control to the interface between the sat nav and the ABS system, only a highly trained technician will do.

An Automatic Can Be a Stick

Back in the old days we used to have manual transmissions with a manual gear selector and a clutch pedal. We also had automatic transmissions that had a single selector used to shift the transmission to the mode of operation needed at any given time. Every car was either an automatic or a stick.

Regular 4 speed automatic.

Today it seems whatever manual transmissions are actually left, are not really any different from the old ones, but the automatic transmissions are very different. We don’t have the old PRND2L up on top of the steering column anymore. We now have all sorts of other things to choose from when operating the automatic transmission. As time goes by things always have to get more complicated.

Most of these features in newer automatic transmissions center on being able to select the gear you want in some fancy new way. Despite the fact that all automatic transmissions actually let the driver select the gear they want, the newer automatics now make something special out of it.

Paddle shifters are the two little levers with the plus and minus signs
used for shifting up and down.

Paddle shifters on the steering wheel or column are now common along with other things that allow the driver to very easily go from a fully automatic mode to a somewhat manual mode. Most cars that have one of these features will usually have a selection within the shift gate that allows them to use the gear selector kind of like a switch. The driver can push the gear selector forward to shift up or pull the selector backward to shift down. These transmission setups use names such as autostick, tiptronic, or manumatic. A few automatic transmissions with manual mode are a completely different thing called a dual clutch transmission (DCT), but this is a topic for another time.

The only difference between and autostick transmission and a regular old automatic is the programming. Automatic transmissions are completely computer controlled on all cars and trucks today. This means that the driver selects the mode such as drive or reverse, and the computer selects everything else such as what gear to use and how and when to shift. Vehicles equipped with an autostick transmission have a mode where the driver is allowed to select the gears manually, but the transmission control computer still does the actual shifting. So the job of gear selection moves from the computer to the driver when the transmission is in the manual mode. Neither the computer nor the driver ever has to worry about a clutch because all of the inner workings of the drivetrain are the same no matter which mode is selected.

In reality this is not that different from the old automatics from years ago. Many people probably remember how grandpa used to drive his old Ford truck with the three speed automatic. With any automatic, including old ones, it is possible to start out driving with the lever on the steering column or on the floor in the L or 1 position. This will not let the transmission shift out of 1^st. Once the vehicle gets moving the driver would then move the selector up to the 2 position and the transmission would shift into 2^nd. Then as the vehicle got moving even faster the driver would move the selector to the D position and the vehicle would shift into 3^rd.

Manual mode is selected by moving the lever to drive then moving to
the right

How is this any different than what the fancy autostick transmissions allow today? The answer is, not much. This manual shifting of an automatic transmission even works when shifting back down from high gears to low gears. The thing is there is no good reason to drive an automatic vehicle this way. The notion that automatics don’t let the driver select the gear they want to use is not exactly true; you just can’t select it as precisely as you can with a regular manual transmission.

Even the autostick transmission will only allow the driver to do so much. If you try to over rev the engine by just letting wind up and not shifting into a higher gear, it will go ahead and do it for you whether you want it to or not. If you come to a stop and you don’t down shift back to first, it will do it for you.

So what is the advantage to this kind of automatic transmission that has become so common? They are slightly more convenient to use, and they give a feeling of more control even if they don’t actually offer more control. With just the right vehicle they can add a little bit of excitement to the driving experience. For some people little things like this matter but chances are most people don’t really care.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

Considering Others

Why is it that when we are behind the wheel of a car we automatically think that nothing we do affects others? In reality driving down a crowded street is no different than walking down a crowded street.

We see many other people as we make our way along with the crowd. When we are walking everything seems to go smoothly. We nod a polite hello to strangers, we give each other space, and we generally interact in a polite manner. This simple interaction almost never leads to blatant offenses between two individuals, because we all know how to behave in these situations.  

Put us in a car and we become crazy jerks. We drive around like everyone else is some kind of moron and we are the only ones that have any business being on the road. We become quick to judge, quick to offend, and quick to let our sense of decency and courtesy go out the window. Every offense that we commit against another motorist we quickly brush off as ultimately being someone else’s fault. We try to teach others lessons from behind the wheel that we think they need, when in reality such things are dangerous.

The world would be a better place if we could consider others when using our automobiles. Just because you can’t look the other person in the eye doesn't mean that you shouldn't show them respect and decency. Any action you take while driving your car is ultimately your responsibility.

When you pull into a parking spot, keep the car between the lines. When you don’t, it becomes difficult for others to park in the space next to you. What makes you think that you deserve two parking spots? Maybe you have never even thought about it one way or another. If your vehicle is too big to efficiently pull into a particular parking spot then find another.

If you have to run into a store or quickly make a similar stop, you are still obligated to park in the parking lot. Nobody is allowed to leave their vehicle parked in front of the entrance where people are trying to enter and exit, and cars are trying to maneuver around each other. You are not the exception, even if it’s only for a minute. When you push your shopping cart around the grocery store, would you leave it at the end of an aisle so that it blocks other shoppers?

When driving on the interstate, the slower traffic must keep to the right. If you are driving slower than even one other car on the freeway, and that car wants to pass, you are obligated to move over. The passing car must not pass on the right. This is not a time for you to teach this other driver what the speed limit is and dawdle along slowly in the passing lane. Notice that name, it’s called the “passing lane” because it is for passing. If you were a pedestrian on the sidewalk would you not yield briefly to another who was trying to get around you?

The diesel pickup spewing black smoke from its tailpipe as it accelerates from a stop light is offensive to most other drivers. These toxins waft through the air all around the intersection for others to breathe. This smoke is the result of something that is broken. Either the fuel management on the truck is broken, or the driver themselves is broken.

Nobody is impressed with a diesel blowing smoke between stoplights, except those that do it. Get your truck fixed or run a different program in your engine computer. Most of the time these smoke blowing drivers are running a computer program that makes this occur.

If you want to blow black smoke from your exhaust, sign up for a sled pulling competition. Then you can see some real torque in action and learn how weak your truck really is. Your perceived right to blow smoke doesn't supersede anyone else’s literal right to not breathe your garbage. You wouldn't walk up to someone on the street and blow cigarette smoke right in their face would you?

Justice is real. Of course it's a BMW.

 While this seems like just a negative rant, it isn't  Most of the offences mentioned here are small and they don’t occur because people are genuinely rude, but rather because we as a society don’t consider others as much as we should. If we stop and think about how our actions behind the wheel have an effect on fellow motorists, even those whom we cannot look in the eye, we would all behave more courteously. This of course, would mean that we would all be happier drivers ourselves. 

Like Perpetual Energy, Not Really

A device that creates electricity and then uses that electricity to create more electricity sounds like a great thing and indeed it would be. The alternator on your can almost do this but not really. Perpetual energy is scientifically impossible, at least with what we currently understand about the laws of thermodynamics.

The alternator is a type of generator so it essentially creates electricity, and to do this it uses electricity, quite often originating in the alternator. The force, or the energy that really makes all of this possible is the rotating force of the engine. The alternator is driven by a belt that is turned using a pulley attached to the crankshaft of the engine. This is the real driving force that makes electrical generation possible within the alternator. The rest is simply a matter of electromagnetic induction.

Electromagnetic induction occurs when a magnetic flux or field passes over a conductor. The point at which the magnetic field collapses around the conductor is the point where voltage is induced into the conductor. This voltage is the pressure that pushes electrons through the conductor, and electron flow is electricity. The alternator actually produces alternating current which is why it’s called an alternator. Before this current actually leaves the alternator it is converted into direct current so the power can be stored in the battery.

In order for this to happen, the alternator has two main parts, the rotor, and the stator. These parts do what their names imply. The rotor rotates or spins and the stator stays in place surrounding the rotor. The rotor contains a large electromagnet that creates the magnetic field necessary for induction. The stator is the conductor that the magnetic field moves through. As the rotor spins, the magnetic field passes through the stator over and over again, thousands of time per minute. The voltage that is induced is then sent to charge the battery and to run all electrical accessories. This electricity even powers the electromagnet in the stator. This may seem like perpetual energy but it’s not even close because the energy to turn the rotor has to come from the engine. The energy to turn the engine of course comes from the gasoline.

Alternator failure is a fairly common problem that most cars will experience at one point or another. When this happens while the vehicle is being driven alternator voltage output goes to zero, or to something very low. Anything electrical on the vehicle will begin to draw power from the battery. This will slowly draw the battery dead until there is not enough voltage to run the fuel pump and fire the spark plugs. The engine then dies. When you try to restart it, the motor won’t even crank because the battery is dead. A jump start can get you going again but only for a few minutes until the car stalls again.

So what can you do the make your alternator last longer? Not much really, it is largely a maintenance free device. Just make sure that the belt is tight and doesn’t squeal. Also, if you run your battery dead because you leave your headlights on or something like that, or if you have a battery that is going bad, this puts considerable strain on the alternator. If you battery goes dead, it is best to recharge the battery with a battery charger rather than just letting the alternator do it. Recharging a dead battery with the alternator once or twice over the life of the car isn’t a big deal, but don’t make it a habit. Be sure to have your battery checked regularly to make sure that it doesn’t slowly go bad and drag the alternator down with it.

Keep these ideas in mind and your own personal power generator will last a long time without much fuss. Perpetual energy it isn’t, but it is essential to the proper operation of your vehicle, not to mention your rear seat DVD player.

Roll In Style Not In Danger

Rolling down the street in your SUV with 22 inch rims can be something that makes you feel like you are king of the road. Oversized rims are all the rage on all sorts of vehicles and nothing adds bling to your ride like wheels that are huge and loaded with chrome.

While you might think it makes your ride look good, and I’m not saying it doesn’t, there are a few problems that you have when you put big custom rims at each corner of your ride. The biggest problem with this type of customization has to do with what we call unsprung weight.

Anything on the vehicle or in the vehicle that exerts the force of its weight on the springs of the suspension system is sprung weight. This would be most of the vehicle, such as the body, frame, engine and transmission, or anything that is placed inside the vehicle like passengers and cargo. This is sprung weight because it is all supported by the springs, and suspension system action can control the force of this weight.

Anything that exerts the force of its weight on the tires only, and not on the springs, is unsprung weight. This is because the weight is below the springs. Things like rims and tires, steering knuckles, brake assemblies, and drive axles fall into this category. These are all items that spring action and suspension articulation cannot control.

Generally speaking the more unsprung weight a vehicle carries, the harsher the ride is. Pickup trucks and many SUV’s that are built for heavy-duty applications tend to have more unsprung weight and therefore have a ride that is not so smooth. Higher unsprung weight can also lead to handling characteristics that are undesirable. All that weight causes the wheels to bounce around more and lead to more situations where they are not firmly planted. Wheels that are not firmly planted cause poor ride quality and poor directional stability.

Oversized rims are very heavy and add a tremendous amount of unsprung weight to the vehicle. Even if the rims are made of aluminum they can still add hundreds of extra pounds, especially if you add bigger tires with the bigger rims. Many times the tires are not much bigger in diameter than the stock tires, but the section height, or the height of the sidewall, is narrower to accommodate the larger rims. This low profile tire adds to the modern, sporty look of the large rims but it further decreases ride quality.

Another common mistake when having custom rims installed relates to the overall fit of the rim and tire assembly. Obviously the tire and rim assembly must fit within the wheel arch and not be so big that it rubs on any of the body or suspension parts. In order to get some wheels to fit properly, or to provide the look that the owner of the vehicle wants, wheel spacers are added to the hub of the wheel and then the tire and rim assemblies are bolted to the spacers.

Wheel spacers can cause big problems and are actually illegal in some states because they can make the vehicle handle dangerously, and they are easy to install improperly which may cause the wheels to fall off while driving. Like the over-sized rims, they can cause excessive wear and tear on the steering and suspension components as well because suspension geometry is changed.

None of this means that you can’t customize your wheels but it just means that you need to be careful. Just because a wheel assembly bolts on doesn’t mean that it will work just fine. With so many different types of custom rims available for nearly every vehicle on the road there is no reason not to find something that will fit just right, and give you the look that you want.

Automotive Thanksgiving

Today is Thanksgiving Day and I have been reflecting upon the things for which I am thankful. Since my mind always runs through ideas related to the automotive world, I have come up with a list of things to be thankful for in the related to cars and trucks. Some of these things are silliness but most of them are genuinely good.

1.       Fuel injection: My thankfulness for fuel injection goes hand in hand with my thankfulness for the fact we don’t have to rely on carburetors anymore. When it’s really cold in the morning fuel injection helps your car run smoothly. Not having issues with silly things like a choke, and fast idle cam adjustment and that kind of nonsense is a good thing. When it’s really hot outside fuel injection helps your car run smoothly. Since fuel injection runs at a much higher fuel pressure, things like vapor lock never occur to leave you stranded out in the hot desert. When it’s wet and rainy outside fuel injection helps your car run smoothly. Air density and humidity are automatically compensated for in ways that carburetors could never handle. All of these things are completely taken for granted by just about everyone who drives. I’m sure old people, anyone who has been driving for the last 30 years or so, remembers the problems associated with carburetors all too well.

Injecting a bit of reliability

2.       Japanese Quality: What I am thankful for here are the Japanese cars that began to sell very well back in the mid 80’s. These cars were small and awkward, but were so reliable they won more and more market share every year. By the time the Japanese manufacturers started to design cars that were not just reliable but were also the size and shape that Americans wanted, they were selling more of these “normal” cars than the domestics. This higher standard that was introduced by the Japanese lead to the domestics slowly raising the quality of their product. When quality goes up across the entire market the consumer ultimately wins.

1985 Honda Civic with reliability that was so far ahead
of so many other things.

3.       European Quality: My thankfulness for European quality relates to ride and handling. Anyone who has driven a BMW or an Audi knows exactly what I am talking about. These cars are well built from the standpoint of being so nice to drive it is just plain fun. I am not sure if I can think of a car that has better handling characteristics and ride quality all wrapped in the same sheet metal than something like a BMW M5. The downside of the Europeans is that they don’t last as long as the Japanese cars, but then if you can afford a Mercedes E class, you can always sell it before it starts to fall apart and then you can go buy a new one.

2013 Ford Fusion

4.       Domestic Quality: Cars are so much better all around than they used to be, that even the domestics are building cars that last a long time. This is what happens in a free market. If you think I am way off base here in my assessment of the domestics, then name some models from the big three that were genuinely reliable and nice to drive from the 80’s or 90’s. They are very few and far between. Ford stands out in my mind as the domestic manufacturer that is really getting things done right. They are doing well building cars that people want to drive and that will last. Chrysler is doing okay too but they haven’t stood on their own two feet since the mid nineties. They are currently owned by Fiat, and before that Mercedes, so they will go as Fiat goes. GM is still owned by the government and the UAW so there is not much positive there, especially considering that GM continues to lose market share, as well as see their stock price fall.

5.       Power Sliding Doors: I have expressed my appreciation for this feature in the past but I cannot express enough how great this future is when you are a family man toting young kids around with you everywhere. This is feature only available on minivans and it is one of the things that make minivans so much better than SUVs for hauling your rug rats around.

6.       Natural Gas Vehicles: Here I go again pumping up the technology that I enjoy so much. My thankfulness for CNG all boils down to the low cost of the fuel. CNG is currently $1.60 per gallon where I live while gasoline is $3.60. I also love that natural gas comes from my backyard. My friends and neighbors literally work in the natural gas fields that surround my hometown. I am thankful that I don’t have to give my money to countries that hate me in order to drive.

7.       Platinum Tipped Spark Plugs: This is really thankfulness for spark plugs that last longer than 10,000 miles. The platinum and iridium tipped spark plugs of today can easily go 100,000 miles before requiring replacement. This means that cars and trucks are much more reliable today and require less maintenance.

The new Ford 6.7 Powerstroke

8.       Diesel Engines: I would be more thankful of course if we had as many diesel engine options here in the U.S. as they have in almost every other country around the world. These engines are so powerful and fuel efficient at the same time that using them more often would really make a tremendous amount of sense. The problem remains that most manufacturers are not quite willing to take a chance on selling these diesel engines in our market. They are getting pretty close however, and I think we will see more of them soon.

9.       Forced Induction Systems: Turbo chargers and superchargers are becoming more popular every year. This is good news for all. Not only are turbos good for making fast cars faster, but they are excellent for making normal cars more powerful with allowing them to consume less fuel. One of the strategies that many car companies are using now is replacing V6 engines with turbocharged I4 engines, and replacing V8 engines with turbocharged V6 engines. In each of these instances the cars on question have the same amount of power when it’s needed but use a lot less fuel when it’s not needed.

10.   Freeways: These are great for traveling across stateliness in order to spend thanksgiving with family. Nothing is better than hitting the highway in a nice running car and cruising to someplace that you want to go. The old adage that it’s not the destination but the journey that’s important rings true for those that love a good road trip.

 Have a good Thanksgiving. If you have a computer to read this from along with internet access, and electricity to run it all then you probably have something to be thankful for as well.

Getting on the CNG Bandwagon

Much has been said lately about compressed natural gas as a means of fueling light-duty cars and trucks. Most people compare the cost of CNG to the cost of gasoline and they want to get onboard the CNG bandwagon. Paying $1.00 to $2.00 per gallon certainly has universal appeal. So what is the best way to get into this world of low cost transportation fuel?

The thing that makes CNG such a great alternative is that it can be adapted to any gasoline engine on the road. The only problem here is that the hardware and software needed to make this happen must be certified by the EPA for each individual application. This means that if you have a 2002 Nissan Maxima you likely won’t be able to convert it to run on natural gas at this time because there is no certified kit for this application.

With a bit of research, i.e. a Google search for CNG conversion kits, you will find all sorts of companies that claim that they can make any car run on natural gas. This is true; they make parts that can be fitted to any vehicle to allow it to run on natural gas. The problem with this is not only are these kits not EPA certified, but they are often such poor quality that they are more trouble than they are worth. The software calibration is too generic and the car never runs quite right. Major power loss will be experienced; increased emissions, and chronically illuminated check engine lights will be common.

Honda Civic NG (GX). Plenty of used civics on the market if you
know where to look.

The other issue here that is perhaps more important than power loss or check engine lights is the fact that CNG fuel systems are designed to handle gaseous hydrocarbons compressed to around 3600 psi. This is a major safety issue. If the components are of high quality and are installed by a certified technician who knows what they are doing then there is no hazard. With this high pressure though, the potential for danger is high if systems are installed by someone who doesn’t know the safety standards that apply to the configuration and installation of high pressure fuel systems.

Many of these problems related to non EPA certified kits and improper installation could be remedied easily if the Feds would streamline the certification process and make it cheaper for CNG system manufacturers to certify their products. Oversight here is important but it should be a little more intelligent. Also, with more educational opportunities for automotive technicians to pick up the necessary skills to work on these systems we could move towards more CNG systems in the many cars and trucks on our streets and highways.

Honestly the most important thing to worry about when it comes to making sure that any vehicle running on CNG is running properly is what is coming out of the tailpipe. Is it possible to make non certified kits work properly? Yes it is. Can this kind of work be done by any shadetree mechanic or a mechanically inclined car owner? No it can’t. With this I would say that what we really need are laws that allow certification of individual vehicles and installations, rather than a blanket certification for exact makes, models, and model years. This could be very easily accomplished, especially in areas that already have emissions testing in place.

The state of Utah is a great example of a state that has taken action on this. They have laws in place that say that as long as the vehicle passes the emissions testing in the most populous counties then they are officially not going to worry about whether or not the kit is EPA certified. The installation must also conform to National Fire Protection Association standard 52, covering gaseous fuel system installation. Even if the kit is EPA certified, the installation must meet this standard in order to pass the Utah state safety inspection. Now how long will it be before the EPA confronts the State of Utah regarding this law is unknown, but it does show that some governments are trying to do what they can.

An older Chevrolet Cavalier CNG

So if you want a vehicle that runs on CNG what can you do? If you drive a late model, full-size truck chances are you can get a certified kit and installation pretty easily. You can even buy a CNG powered pickup truck through your local dealership in some instances. The vehicles that you can buy brand new with the CNG systems installed are usually referred to as having a factory conversion. The auto manufacturers themselves work with third party companies to equip their vehicles with some very nice systems that integrate flawlessly and can be serviced by dealership technicians.

The other option that is much less expensive is to find a nice used vehicle from about 10 years ago when there were many options on the market. The domestic manufacturers got out of the game of doing factory CNG conversions because they got a little preoccupied with keeping their factory doors open and not going out of business. Because the auto industry has stabilized a bit in the last year or two they are getting back into the CNG game. From 10 years ago you can find all sorts of trucks and vans and large SUV’s that are still on the road and with very low mileage. The low mileage results from the fact that many of them were part of some government fleet and did not get driven much.

2013 Ram 2500 CNG. This is very nice factory equipped CNG truck.

If you don’t want a truck you can find a nice used Chevy Cavalier, Ford Contour, or Honda Civic that runs on natural gas. The Honda Civic is the only CNG powered vehicle that has been in continuous production since 1996. This is a great car but it is a dedicated system so you can only run it on CNG and it cannot be switched over to gasoline on the fly like the bifuel vehicles can.

Good options do exist; check the classifieds in large markets like Salt Lake City, Oklahoma City, or Los Angeles. I mention these cities because they are kind of the epicenters for CNG powered vehicles. Oklahoma and Utah have a tremendous amount of natural gas, and the pipelines that run out of Utah head straight to Los Angeles. The public gas utilities in these places have also done a lot to build infrastructure such as fueling stations. Most of the residents of Salt Lake City and the Wasatch Front of Northern Utah live within a few minutes of more than one CNG station so they there are a lot of CNG cars and trucks around. The Utah laws regarding CNG conversions mentioned earlier also make this area friendly to CNG vehicles. This is a good example of how government restrictions and the loosening thereof can help the private sector to build flourishing market better than anything else.

Filling up at home would be cheap and convenient.

You can purchase home fueling units that install easily as long as you have a gas line to your garage. These compressors can fill your tank slowly over a few hours. You can hook your vehicle up at night and by the time you head out for your commute in the morning it will be full. These machines are rather expensive but the cost of the fuel when filling up at home is outrageously cheap, often less than .50 per gallon.

When buying a used CNG vehicle, make sure that the CNG system is legal and that it works properly. Run away from anything that has a chronic check engine light, or anything that cannot be verified as EPA certified, or a factory installation. Also be aware that most CNG tanks expire after 15 years and must be removed from service. Some classified ads will say that the tanks can be recertified. This is not true if the expiration date for the tank as listed on the manufacturers label has passed. Each tank must also be inspected every 3 years for safety reasons. These inspections will be listed on a label on the tank not from the manufacturer  These inspections are cheap and easy to get from a certified CNG fuel system inspector. 

So consider your options. If you want to experiment with driving a CNG vehicle then find something old and cheap and see how you like it. If current trends towards more CNG options is truly on the horizon then in a few years you will have even more options. With this, you too can use cheap fuel that comes from our own back yard rather than from some exotic foreign location. Cheap clean fuel is real, and you can use it too.