Gas Type by Car: Regular, Premium, Diesel or E85 / Mercedes-Benz / GLEMercedes-Benz GLE Gas type by year YearGas type2027Premium2026Premium2025Premium2024Premium2023Premium2022Premium2021Premium2020Premium2019Premium2018Premium (flex-fuel E85 engine available)2017Premium (flex-fuel E85 engine available)2016Depends on engine: diesel or premium (flex-fuel E85 engine available) Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).