Honda Civic GX Specifications

The GX was originally introduced with a 1.6 liter I4 engine. The 2001 model make-over carried a 1.7 liter engine. Beginning in model-year 2006, the 1.8 liter inline four-cylinder engine was introduced to the Civic lineup.

Compression in the Civic GX is 12.5:1. This is to accommodate the 130-octane natural gas that powers the car. Performance of the Civic GX (113 hp) is significantly less than that of the comparable LX model (140 hp).

The CNG cylinder (fuel tank) is carried in the trunk of the car and holds according to Honda, 8.0 GGE (Gasoline Gallon Equivalent) at 3600 psi. Although most owners report that its rare to see 8GGE fillups - 5-6GGE fillups are typical from an "empty tank."

Range on a full 3600 psi fill is variable, depending on driving conditions and driving technique. While Honda claims an estimated 225–250 miles from a full CNG tank charge, independent tests have found a lower ranges, at 180–200 miles and "just over 200 miles". The EPA rates the 2009 Honda Civic GX at 24 equivalent MPG city and 36 equivalent MPG highway. Independent tests with mixed driving usage found rates of "nearly 32" and 26.8 equivalent MPG. The estimated fuel cost for this vehicle to drive 25 miles for a combination of city and highway driving is $1.47 using CNG. The GX qualifies for HOV Laneaccess in California.