As part of a Honda Civic GX long-term test, Edmunds decided to install a home-based CNG pump in order to fuel the car. First, they had the pump installed and approved by a city inspector. Now that they've been driving the car a while, they posted a cost analysis of operating the Civic GX in this fashion. It turns out that in addition to being better for the environment, a home CNG pump can provide substantial savings.

"We pumped the GNG equivalent of 51.888 gasoline gallons through the Phill home unit during March, and figure that electricity to run the pump cost $40.29 while the natural gas itself cost $91.69, for total cost of $131.46, or $2.53 per gallon," the report said. "That's $1.18 less than the prevailing price of unleaded regular gasoline in our part of Southern California, and anywhere from seven cents to 32 cents a gallon-equivalent less than the various retail GNG pumps in the area are charging for their natural gas. (The range is so great because one pump is operated by a city and is priced pretty much at cost— it was $2.60 a gallon when we checked two days ago)."

In addition, they just received authorization from the natural gas utility for a home refueling unit discount that should drop the cost of filing up to well below $2 per gallon. That's for a car that's been averaging 32 mpg in real use, or slightly more than you could expect from a garden-variety, gas-powered Civic (rated at 25/36 mpg).

Image credits: Honda Media Newsroom (car), Edmunds.com (pump)