Gas Type by Car: Regular, Premium, Diesel or E85 / Fiat / 500Fiat 500 Gas type by year YearGas type2023Regular2022Regular2021Regular2020Depends on engine: regular or premium2019Depends on engine: regular or premium2018Premium2017Premium2016Premium2015Premium2014Premium2013Premium2012Premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).