From Green Right Now Reports
How do cars pollute? In two main ways, through inefficient mileage (guzzling a gallon of gas every eight or 10 or 14 miles) and through tailpipe emissions.
There’s the pollution associated with manufacturing, also, but to keep it simple let’s stick with emissions and mileage. Obviously, both affect the air. Think of mileage as a measure of your car’s pollution volume over time – if a gallon of gas doesn’t take you very far, you have to burn a lot more gas — and emissions as the chemistry of that pollution; if the mix is particularly noxious, your car will be a bigger offender than one with better tailpipe controls.
So if you want to buy the cleanest car you can — in the price range you need — you’ll look at both factors. Fortunately, the U.S. Environmental Protection Agency has already done this work, assigning a “greenhouse gas” score to most models. Find it at the EPA’s Green Vehicles website.
