Gas Type by Car: Regular, Premium, Diesel or E85 / Pontiac / BonnevillePontiac Bonneville Gas type by year YearGas type2005Regular2004Depends on engine: regular or premium2003Depends on engine: premium or regular2002Depends on engine: premium or regular2001Depends on engine: regular or premium2000Depends on engine: regular or premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).