Driving the natural-gas-fueled version of the 2012 Honda Civic brought me back to my high-school chemistry class. As I thought about how Honda derives a miles-per-gallon figure for this car, I considered the physical states of a liquid versus a gas.
That train of thought only explained why the natural gas tanks in the car impinged so much on the trunk space, yet still only carried 8 gallons. The 13.2-gallon tank in the 2012 Honda Civic EX-L used up much less space. As my chemistry teacher explained, a gas takes up more volume than a liquid.
It took a little Web research to find that Gasoline Gallon Equivalent (GGE) is a commonly used measurement for compressed natural gas (CNG). A GGE of CNG contains the same amount of energy as a gallon of gasoline. Being a gas, that GGE of CNG takes up more volume, and means there is maybe room for three grocery bags in the back of the Civic Natural Gas.
Given its smaller fuel capacity, the Civic Natural Gas does not boast the same range as its gasoline counterpart. A Civic EX-L goes an average of 422 miles on a full tank, while the Natural Gas version can only go, on average, 248 miles after its tanks have been topped off.
Add lesser range and trunk space to the fact that CNG filling stations are much, much rarer than gas stations, and the question arises, how does the Civic Natural Gas justify itself?
Not hurting its case is the fact that fuel economy is about the same between the CNG and gasoline Civics. Same amount of energy per gallon, remember?
The most immediate tangible benefit from the Civic Natural Gas is that CNG costs much less than gasoline. A survey of stations around the San Francisco Bay Area, using CNGPrices.com, showed prices ranging from $1.99 to $2.80 per GGE, with $2.09 being the most common price in an area where gasoline is going for over $4.00 per gallon. That means a full tank in the Civic Natural Gas for $16.72.
For those willing to think beyond the pocketbook, CNG produces less pollutants than gasoline. According to a Department of Energy study, the Civic Natural Gas emits 20 to 40 percent less carbon monoxide and 80 percent less particulate matter than an equivalent gasoline-powered car. It also reduces greenhouse gas emissions by 30 percent. Under California's emissions rating system, the Civic Natural Gas qualifies as an Advanced Technology Partial Zero Emissions Vehicle, making it eligible for the car pool lanes.
And the politically minded might want to consider that CNG is a domestic fuel source, so it lessens the pressure to become embroiled in foreign conflict.
The Civic Natural Gas suffers a power hit compared with its liquid-powered brethren. Where the 1.8-liter four-cylinder engine in the Civic EX-L produces 140 horsepower, that same engine only generates 110 horsepower in the Civic Natural Gas. Torque likewise goes down from 128 to 106 pound-feet.
That power loss becomes palpable when flooring the accelerator, either to merge on a freeway, pass another car, or through a misguided sense of fun. The Civic Natural Gas is not a fast car, taking its sweet time in the run up to 60 mph. Under this sort of acceleration, it showed a preference for very specific rev ranges, getting a boost after each gear change for a short amount of time.
The five-speed automatic transmission is only remarkable for the three low ranges it offers. There is no manual mode, but I could practically choose gears by rowing through D3, D2, and D1, each of which caps the top gear the transmission can go into. A sixth gear might seem like a good idea, but I found the engine speed maintaining just over 2,000rpm at speeds of 70 mph.