CNG Motor Fuel

The US has been using CNG ("methane") in homes for decades. It burns very clean, is relatively inexpensive, and we source this fuel domestically in the USA. In fact, most countries in Europe and Asia have also been using CNG as an alternative fuel for vehicles for many years. They use vehicles that use dedicated CNG engines as well as "bi-fuel" engines (runs on either CNG or gasoline). This was a mainly a result of of their high gasoline prices. Well, now the US is facing increased gasoline prices and people are searching for ways to reduce their dependency on traditional fossil fuels. Further, natural gas prices are near record lows! With gasoline over $4.00 per gallon and CNG less than half that price in most areas, how can we take advantage of these low fuels costs. As mentioned, most of us can't afford to just sell our car and then buy a brand new NGV (natural gas vehicle) for $30,000. This is where the CNG car conversion kit becomes of interest.

Yes, CNG car conversion kits exist. In fact, the technology has been around for decades and is very reliable. Two main types of systems are the sequential electronic fuel injection kit, which is usually the most efficient and technologically sound for OBDII (post 1996 car models), and the "venturi" or "mixer" system which is cheaper, does not use a computer, and bypasses the injectors. The basic components of the CNG car conversion kit are the CNG cylinder (high pressure tank), the regulator (reduces from high pressure to low pressure), the ECU (electronic control unit), and the injectors (for sequential fuel injection OBDII kits) or the mixer (for "venturi" or carburetor kits).

The single most expensive part of the kit will likely be the CNG cylinder. The Type 1 cylinders are the most common and affordable, and are made of heavy steel. But there are 3 other types made of complex fibers and materials. While light-weight, these can be much more expensive. New type 1 cylinders, depending on the volume size, can be as much as $1500. Type 4 can easily be five times as much.

The regulator will bring the 3600 PSI high pressure gas down to a level your engine can utilize. Then the injectors will spray the CNG inside your manifold as a replacement to gasoline. The best part is that this is all controlled by computer, or ECU. The ECU will make sure CNG levels are accurate and safe for your engine. It is installed via your vehicle's OBDII computer and calibrated by a software that should accompany your CNG kit. This type of CNG conversion will allow the driver to operate with gasoline or CNG. There will be a switch on your car's dash that lets you switch fuel types on the fly, without hesitation. Your original gasoline fuel system is not damaged in any way . You can use CNG while commuting around town and then use gasoline on the long road trips where CNG is harder to find. (Note: The CNG infrastructure is rapidly expanding across the nation. If it's not convenient to you right now, it soon could be.)

Not including the cylinder, CNG conversion systems can range in price from $1,000 up to several thousand dollars for newer EPA certified kits. Some places, such as California, won't let you legally install anything but an EPA certified kit. Even then, you can only install the kits on certain vehicle and engine types. Installation should take from four to eight hours, and should only be done by an ASE certified mechanic or a mechanic with CNG experience. Contrary to internet stories, there is no such thing as a federally licensed CNG installer. There may be private certifications out there, but it doesn't necessarily make the installer any more "legal" or better than the next guy.

Like any auto part, there are plenty of low quality or possibly unsafe kits out there for CNG car conversion. Government rules and regulations can be very confusing and vary from state to state and even city to city. Be sure to research the subject thoroughly to learn more before you purchase your CNG conversion kit. An informed decision is the best decision.