Compressed Natural Gas (CNG) Conversions

Back of a Car
Wisconsin DMV/Flickr

Compressed natural gas (CNG) conversion kits allow a mechanic to convert a conventional gasoline car to one that runs on the CNG. Although the process is complex, it is not necessarily difficult and quite do-able. And if you are mechanically inclined, it could feasibly be done in your own garage. The other option is to find a willing mechanic that will install a CNG kit for you!

This type of fuel also comes with its fair share of advantages including more engine power, better fuel efficiency and longer engine life overall. However, there are also several concerns you should address before committing to a full conversion of your vehicle. You should consult a trusted mechanic for more information regarding the logic of making this change.

Common Concerns

One potential hoop to jump through could be emissions certification for your particular state — some states require special conditions since you'd be changing the vehicles "engineered" fuel type. They all differ, and some are easier to work with than others. The U.S. Department of Energy offers this emissions certification information and CSA America offers a searchable database of compressed natural gas cylinder inspectors.

Another be-aware-before-you-do-it-item is to locate the CNG fueling stations in your area to be sure you’ll have regular access to the fuel. This CNG and alt-fuel station finder includes pricing for the United States. Another alternative, if you have natural gas in your home, is to install a Phill home refueling appliance. These devices compress and dispense a tank of fuel in about 8 hours. They are designed to be attached overnight, delivering a full tank by morning. Another option could be to install a CNG compressor at your house, which typically runs upwards of $4,500.

Where to Get the Kits

Fortunately, there is no shortage of vendors for these CNG conversion kits. Websites like CNG Interstate which not only offers a bi-fuel CNG/gasoline conversion kit and CNG cylinders but also a plethora of information related to understanding how they work. Here, you can carry order online with prices starting at $1450 for full conversion and $2200 for dual-fuel conversion. 

Energy and Water Solutions (EWS) also offers bi-fuel CNG/gasoline conversion advice for home installation and a reference guide for EPA regulations governing engine modifications. Although once a premier site for ordering parts as well, the sales portion went down in 2015 but remains live as a resource for mechanics.

Speaking of, chances are your local mechanic will also be able to get the right tools for the job, but if you live in the Denver Metro area, Redmark CNG Services offers alternative fuel conversions for a variety of American vehicle makes and models with installations available directly at their facility. Similarly, Tulsa Gas Technologies offers full conversions for $11,000 to $12,000 in Tulsa, OK, and Dallas, TX.