Gas Type by Car: Regular, Premium, Diesel or E85 / Pontiac / Firebird/Trans Am/FormulaPontiac Firebird/Trans Am/Formula Gas type by year YearGas type2002Depends on engine: regular or premium2001Depends on engine: regular or premium2000Depends on engine: regular or premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).