Gas Type by Car: Regular, Premium, Diesel or E85 / Mercedes-Benz / GL-ClassMercedes-Benz GL-Class Gas type by year YearGas type2016Premium2015Premium2014Premium2013Premium2012Premium2011Premium2010Premium2009Premium2008Depends on engine: diesel or premium2007Depends on engine: diesel or premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).