Gas Type by Car: Regular, Premium, Diesel or E85 / Chevrolet / Van 15/25 ConversionChevrolet Van 15/25 Conversion Gas type by year YearGas type2008Regular (flex-fuel E85 engine available)2007Regular (flex-fuel E85 engine available)2006Regular2005Regular2004Regular2003Regular Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).