Gas Type by Car: Regular, Premium, Diesel or E85 / Chrysler / 300 SRT8Chrysler 300 SRT8 Gas type by year YearGas type2014Premium2013Premium2012Premium2010Depends on engine: regular or premium2009Regular2008Depends on engine: regular or premium2007Depends on engine: regular or premium2006Premium2005Depends on engine: regular or premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).