Gas Type by Car: Regular, Premium, Diesel or E85 / Roush Performance / MustangRoush Performance Mustang Gas type by year YearGas type2021Premium2019Premium2017Premium2016Premium2015Premium2014Premium2013Premium2012Premium2011Premium2010Premium2009Premium2008Premium2007Premium2006Premium2004Premium2003Premium2002Premium2001Premium Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).