Honda has been selling natural gas powered compact passenger cars for more than ten years. For 2012, Honda Civic line consists of Civic, Civic Si, Civic Hybrid, and Civic HF (already offered at dealers), and Civic Natural Gas which used to be called Civic GX. The last of the line Civic is actually the only natural gas powered OEM-built passenger car available for sale in the U.S. and it will be available at dealers in autumn. At the moment the Civic Natural Gas is sold in just four states (New York, Oklahoma, Utah and California), but Honda is expanding its retail sales to nation-wide.
Operating entirely on Compressed Natural Gas and driving just like the gasoline model, the Civic Natural Gas is 12.5% more fuel efficient in the city and 5.5% more effective on the highway compared to its predecessor. What helps to preserve the exclusive properties of Natural Gas is the intake and exhaust regulators, special fuel injectors, and valve seats. The model's fuel tank is situated among the rear wheels. A higher compression ratio is achieved due to stronger connecting rods and special pistons. Honda's special ECO Assist technology is included to improve efficient vehicle operation. This technology also provides a visual feedback for efficient driving style confirmation. As a vehicle which runs on fossil fuels, it produces the lowest CO2, rather than all vehicles, except for a couple of hybrids. The vehicle is likely to please customers with big concern for environment. Honda Civic Natural Gas was already approved by the environment-concerned authorities of California. While back in 2009 the sales of the CNG-burner went up after it was graded as the greenest vehicle in the land multiple times by the ACEEE (American Council for an Energy-Efficient Economy), new Civic GX will surely gain popularity.