Significance

• Worldwide, approximately five million vehicles currently use natural gas for fuel. Many of these vehicles were retrofitted to use CNG. Often they are part of a service vehicle fleet. For individual vehicle owners, the options for buying a CNG vehicle are limited. Buyers must special-order CNG-powered vehicles the manufacturer. The buyer can request a vehicle that can use both gasoline and CNG. Although it is not difficult to accomplish, many consumers are not quite ready to retrofit a gasoline-powered vehicle. Several automotive aftermarket kits help people ease the transition to CNG.
  
  

Types

• If you are not ready to take on a project of this size, your next step is to look at Honda's CNG vehicle - the Civic GX. For now, it is the only game in town. Buyers can order this vehicle directly from the manufacturer. Honda delivers the GX within 30 days, from its prebuilt model year inventory or within 60 days, if stocks have been depleted. The Environmental Protection Agency gives Honda's CNG vehicle high marks. It is the cleanest internal combustion vehicle on the planet. The sedan with 4-cylinder engine and 5-speed automatic transmission has a fuel economy rating of 24 mpg for city driving and 36 mpg for the highway.
  
  

Features

• Since CNG is not liquid like gasoline, the EPA rates its fuel efficiency using the equivalent of a gallon of gasoline (GGE). The amount of CNG in cubic feet that a vehicle burns, compared to a gallon of gasoline is under fifteen percent. This is significantly less than fuels like liquid natural gas, methanol, ethanol and biodiesel fuels as well. It also costs less per GGE than gasoline. CNG is safer to use than gasoline and diesel fuel because combustion requires the right mix of air and fuel at temperatures over 1,100 degrees Fahrenheit. Gasoline and diesel both have lower combustion temperatures than CNG.
  
  

Benefits

• CNG vehicles have 90% to 97% lower carbon monoxide emissions than other fuels. Their carbon dioxide emissions are 25% less. Their nitrogen oxide emission rate is 30% to 60% lower. They emit 50% to 75% fewer hydrocarbons, fewer particulates and toxins and carcinogens. The EPA reports that some owners of true CNG vehicles have reported double or triple engine life for their vehicles.
  
  

Considerations

• The driving range for CNG vehicles is less than that of comparable gasoline-powered vehicles, because the energy equivalent in actual British Thermal Units is less than gasoline. Finding fuel can be challenging when driving long distances. However, for local driving, vehicle owners can set up a personal fueling station by buying extra CNG and storing it in tanks in their garages. Finally, although the supply of CNG in the United States is more than adequate for current consumption, increased demand could result in higher prices and less availability.