Gas Type by Car: Regular, Premium, Diesel or E85 / Acura / RSXAcura RSX Gas type by year YearGas type2006Depends on engine: regular or premium2005Depends on engine: regular or premium2004Depends on engine: regular or premium2003Depends on engine: regular or premium2002Depends on engine: regular or premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).