Compressed Natural Gas (CNG) How To Pay Less For Fuel

Published on April 20th, 2012 | by Charis Michelsen


How To Pay Less For Fuel (Maybe)

Diesel is expensive. E10 is expensive. Regular gasoline is expensive. Electric cars and hybrids aren’t exactly cheap, either. Unless we all want to hop on a bicycle for dozens of miles a day, we may all be (financially) screwed. Or there are other fossil fuels – liquefied petroleum gas (LPG) and compressed natural gas (CNG) are gaining popularity as potential new fuel sources. It’s possible to get an otherwise normal car to run on either, but the question is whether or not the immediate cost will be offset in the long run.

Step One – If It Ain’t Broken, Don’t Fix It

The first question is whether you should convert your existing car, buy a new car, or stick with what you have and just use your own two feet to offset rising fuel costs and carbon emissions. If you’ve got a diesel, you might as well either keep it or sell it and buy something else; diesel is difficult to convert and expensive. From now on, we’re just going to assume you’ve got a bog standard gas-powered something and that you’re not looking for anything with massive batteries in.

A number of CNG-powered vehicles are also available straight from the dealer; for example, Honda’s had a CNG Civic for a couple years that looks great, can be filled up at home (with the proper equipment), and really has only one minor issue (if you’ve seen any of Gas2’s Chicago Auto Show Honda posts, you know what it is). CNG is fairly inexpensive, and fairly common – for American drivers, there are a couple of easy options when it comes to finding fuel.

Step Two – So You Want To Convert Your Car

Conversion can be a lot less expensive than buying an entirely new car, so if you’ve decided to go with that option you can still choose either LPG or CNG. CNG conversions are difficult in the United States, requiring EPA and/or CARB certification. NGV America has a list of the cars with approved conversions. It should be noted that you can still get a shop to convert your car if it’s not on that list, but it can become a legal issue. If your car is on the list, congratulations – you’ll pay around $3/gge (as of Thursday, 4/19/2012) for an initial $8K-$16K conversion cost.

You could also go for the LPG option; the most expensive part of that is the fuel injection system (less expensive than a CNG conversion). The car keeps its gas tank (it needs gas to get going and then automatically switches over to LPG after a couple minutes) and adds an LPG tank. Unfortunately, there aren’t many LPG kits for the U.S. either due to EPA regulations (it’s way more popular in Europe). The up side is that it’s only $3k-$4K to do the conversion, and LPG is still cheaper than normal gas.

Do not try to convert your car to CNG or LPG at home, by the way, unless your job also involves alternate fuel conversions. DIY conversions to electric are both much easier and won’t put you on the wrong side of the EPA.

Step Three – Maybe The Bicycle Is Easier After All

There isn’t an easy answer to rising transportation costs; I’m particularly fond of the EV option (especially when it comes shaped like a DeLorean and that I cannot afford one is utterly tragic). But there are also hybrid cars, super efficient cars, scooters, motorcycles, bicycles, public transportation, and your own two feet – most of which also have the awesome side effect of lower emissions.

What’s your favorite? Let me know in the comments!

Image: Wikimedia Commons

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About the Author

spent 7 years living in Germany and Japan, studying both languages extensively, doing translation and education with companies like Bosch, Nissan, Fuji Heavy, and others. Charis has a Bachelor of Science degree in biology and currently lives in Chicago, Illinois. She also believes that Janeway was the best Star Trek Captain.

  • http://MrEnergyCzar MrEnergyCzar

    Keep it simple, drive a Volt. I’ve spent $70 on gas the first 7,000 miles in my Volt so far…..


  • http://Facebook Kevin vonMoses

    I would like to write a brief note, but your ignorance about energy, cars and ‘carbon foot print’ is appalling for people who presume to inform others on the subject(s).

    PLEASE take the time to read Danial Yergin’s ‘The Prize’ to at least have an inkling of how we got were we are in terms of fuels…

    ALL fuels have a British Thermal Unit, (Btu) or equivalent per gallon. You cannot compare a fuel without first seeing if they are equivalent, and in the case of CNG, (37500 Btu’s) and Diesel, (138,500 Btu’s) it should be OBVIOUS that given the same horsepower/Btu demand one will some 3.7 times as far on the same gallon or equivalent of tank.

    A Diesel tank can be MUCH smaller, (about 3.7 times smaller and can fit under a seat, while the CNG tank is a gas under pressure and has to be a specific shape and 3.7 times bigger to have the same ‘range’.

    Energy is energy, it isn’t ‘greener’ because you say it is… If fact be known and the Liberal part of your misEducation could be set aside, ALCOHOL, (74500 Btu/gal) is the only ‘renewable’ fuel because any woody biomass can be thrown in with sugar beets and some yeast to produce fuel grade alcohol. The mantra ‘food or fuel’ is both disingenuous and ill informed.

    The REAL problem is that consumption far outstrips production because cars, on the average, are only 3% efficient.

    Don’t think so? Try this: at 8hp, the lifetime average chassis horsepower demand for a 5,185 pound truck, (my Nissan Frontier) multiply that by 41.42 to get the chassis Btu demand and time the distance on your last tank of gasoline, and divide that by the number of gallons you filled up with times 114,132, (Btu’s in a gallon of gasoline).

    I am not a devotee of any particular fuel, (I do lean towards alcohol, but that is more a matter of pragmatism and philosophy; not for discussion here) and I happen to think Jean Luc Picard was a better character as Star Trek Captain.

  • Vicky

    I’ll surely go with Electric Vehicles. Its true that they are expensive but long term expenses are quite less and well you don’t have to buy expensive fuel for your car.

    • Kevin vonMoses


      Look at a couple of things the Utilities, (who have the most to gain) don’t want you to notice: The environmental impact of creating and disposing of ‘batteries’, the finite resource the materials for those batteries eventually will be, (same for fossil fuels) AND Where did the electricity come from?

      Most power plants today, thanks to narrow minded and unfounded fear is from coal, so the transfer of pollution is from your ‘tail pipe’ to the Utilities who, believe it or not, have FEWER regulations on pollution that the Automotive Industry does.

      If you think Electricity Rates will remain the same as the consumption goes up, you are mistaken.

  • t_


    As things are going, petrol is going to cost more and more and an alternative is needed, so you and everyone can keep their wealth from slipping thrue their fingers. Every alternative counts for the prices to be in a reasonable range. I drive a converted car for many years now. It is ~ 30 – 40 % cheaper to run my car on LPG than on gasoline. I live in Europe and the fuel mix in my country is already clear – we have had the alternatives for more than a decade and those fuels are available. Think what will happen if the americans have the alternative to choose. Even gasoline prices could go down only becouse of that, becouse the USA is a big consumer, very big. Those are the figures of the sold fuels for the last year in my country:
    Gasoline – 35.5%, Diesel – 37.9%, LPG – 24%, CNG – 2,5%.
    Imagine, that was the situation in the US.

    • Kevin vonMoses

      Actually, you would go nearly twice as far on a fill-up of Alcohol… Just because of the difference in Btu content: 34,500/gallon/CNG vs 74500/gallon/Alcohol.

  • April

    I know that hybrids and EV’s are expensive but I think they are worth the price in the long run, because by that time,you would be savoring the huge chunks of savings in your pocket. However if your office or school is less than 3 to 5 blocks away from your house, then why not use a bicycle instead.

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