Fuel Efficiency by make / model
Update information for your driving habits
Converting burning gas to CO2 emissions
How do we calculate the CO2 emissions?:
The calculation is based on simple chemistry. Basically, when you burn gasoline, you consume gas (C8H18) and Oxygen (O2) and release Carbon Dioxide (CO2) and Water (H2O).
This reaction produces the heat and energy to drive your car. A full explaination of this can be found here: http://local-warming.blogspot.com/2008/01/explain-pounds-of-co2-per-gallon-of.html.