Here's a website that will help when making the decision to buy a more energy efficient vehicle or to see where your car ranks. Go to www.fueleconomy.gov to find articles about gas mileage, emmissions, and pollution ratings, plus alternative fuels, and hybrids.
There's a tool to find your cars energy impact score and compare it to other cars. You can try it at http://www.fueleconomy.gov/feg/sbs.htm.
They also have information about a new rebate called CARS (car allowance rebate system) to trade in your inefficient vehicle. You can get 3500 to 4500 for buying a fuel efficient car, and it begins sometime this month! Here's the link http://www.fueleconomy.gov/feg/cars.shtml.