Kia Optima Gas type by year

Year	Gas type
2020	Regular
2019	Regular
2018	Regular
2017	Regular
2016	Regular
2015	Regular
2014	Regular
2013	Regular
2012	Regular
2011	Regular
2010	Regular
2009	Regular
2008	Regular
2007	Regular
2006	Regular
2005	Regular
2004	Regular
2003	Regular
2002	Regular
2001	Regular

Source: U.S. EPA / DOE fuel economy data (fueleconomy.gov).