Washington, March 1 : Honda’s Civic GX natural gas car has been named by the American Council for an Energy-Efficient Economy (ACEEE) as the greenest vehicle of 2008 for the fifth consecutive year.

According to a report in ENN (Environmental News Network), three other Honda vehicles also featured in the top list of the ACEEE.

In the 11th annual ACEEE's ranking of environmentally responsible vehicles, the natural gas-powered Civic GX ranked first with the gasoline Civic, Fit and Civic Hybrid joining the list of the 12 most environmentally-conscious vehicles available to the public.

This is the eighth year in a row that a Honda vehicle received the number one ranking and the seventh consecutive year that Honda vehicles held at least four positions in the top 12, an impressive one-third of all vehicles on the list.

For determining the rankings, the ACEEE used a singular measure that incorporates fuel economy, health-related pollution impacts and global warming emissions.

All vehicles are then analyzed and given a "Green Score." This score is used in ACEEE's ranking system, resulting in a ranking of each vehicle's total environmental performance, including a list of the 12 "greenest" and 12 "meanest" vehicles.

According to the report, the Civic GX, first introduced in 1998, is the cleanest internal combustion vehicle certified by the EPA (Environmental Protection Agency) and is 90% cleaner than the average gasoline-powered car on the road today. (ANI)