Gas Type by Car: Regular, Premium, Diesel or E85 / Jeep / CommanderJeep Commander Gas type by year YearGas type2010Regular2009Regular (flex-fuel E85 engine available)2008Regular (flex-fuel E85 engine available)2007Regular (flex-fuel E85 engine available)2006Regular Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).