Gas Type by Car: Regular, Premium, Diesel or E85 / Buick / LucerneBuick Lucerne Gas type by year YearGas type2011Regular (flex-fuel E85 engine available)2010Regular (flex-fuel E85 engine available)2009Regular (flex-fuel E85 engine available)2008Regular2007Regular2006Regular Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).