'Green Score': 57
Mileage: 36 mpg Hwy, 24 mpg City (gallon equivalent)
Sticker price: $25,190
The Civic GX doesn't run on gasoline, but on compressed natural gas, which burns a lot cleaner.
If you don't live near a publicly accessible natural gas fueling station, dealers that sell the GX also sell at-home fueling stations that tap into your household gas supply. The GX is only sold to retail customers in California and New York, however.
The GX got the highest score of any car on the list. The next-closest competitor in this category was the Honda Civic Hybrid, which runs on gasoline. It earned an ACEEE "Green Score" of 51.
NEXT: Mid-size: Toyota Prius
Last updated February 03 2009: 1:00 PM ET