CNG-powered vehicles have generally cost more to purchase new than comparable gasoline models. Suggested retail for the Civic Natural Gas is $26,155 plus $770 for destination charges. A comparably equipped, gasoline-powered Civic LX lists for $18,242. A home refueling unit, plus installation, can cost upwards of $5,000, making the premium to drive a CNG Civic can top $10,000, before incentives.
CNG stations are not available in some areas. Check the U.S. Department of Energy Web site for availability in your region.
Range anxiety. With a usable range of 160-180 miles, you’re going to feel range anxiety as soon as the low fuel light comes on. Given the scarcity of public access CNG filling stations, that's a concern.
Gassing up with CNG
Even if you have access to natural gas, refueling can be a hassle. There are a limited number of refueling stations in the United States, and many are operated by fleets and not open to the public.
In addition, the pressurized CNG pumps take some getting used to. They use a special fitting to seal to the vehicle, something most motorists might not recognize. A Honda representative suggested a 15-minute training session before using the pumps. Many pumps also work on a card-reader system specific to the fuel supplier. Users are billed monthly, which may be less convenient than handing over cash.
And the pumps take about twice as long to fill the car as a regular gas pump.
If you choose to fill up with a home system
An advantage of refueling stations over a home unit is that the gas is already pressurized, so the tank can be filled in a matter of minutes. Gas fed to the home is under very low pressure. The home refill device acts as both a pump and a compressor, which is why it takes overnight to fill the tank. But refueling at home can cost much less than a refueling station, so it can be worth the wait, especially if the refueling is done overnight. Of course, it would take time for the payback of the initial unit cost and installation. Also, installation is likely to require a building permit.
Honey, they shrunk the trunk
Even though a CNG tank is larger than a gasoline tank, you get fewer miles per tank. With the Civic Natural Gas, roughly half the trunk capacity is given over to the tank, with 6 cubic feet left for your luggage. The range between fill-ups also shrinks. Honda claims a 220 to 250 mile range from the Civic Natural Gas. But when we tested a 2008 model, we couldn’t get more than about 130 before the low-fuel indicator came on.