The 2002 Pontiac Grand Am has a fuel tank (gasoline) with a capacity of 14.3 US/Imperial gallons. The 2002 Grand Am with the base 2.2L engine has an EPA estimated highway of 30 miles per gallon and 22 city.
You mileage will vary dependent on the condition of your car, your driving habits and which engine/transmission you have. Check the web site below for exact specs. http://consumerguideauto.howstuffworks.com/1995-to-2005-pontiac-sunfire-6.htm