Two different engine variants were used on the 2014 Kia Optima, including a 2.0 liter turbocharged 4Cylinder and a 2.4L 4Cylinder. The 2.0T engine requireS5.3 quarts of SAE 5W-30 full synthetic motor oil, but You can substitute SAE 5W-40 over the short term. The 2.4L engine requireS5.3 quarts of SAE 5W-20 full synthetic, but You can substitute SAE 5W-30 for short periods. The reason these substitutes aren't recommended for the long term is because of their inferior viscosities -- You should always use the recommended engine oil with the lowest numbers in its weight, as this is a thinner oil. Thicker oil will introduce friction to Your system, which can and will lead to premature engine wear and tear.
Jim
September 3, 2021
The owners manual recommends 5w20. However the manual is clear that either 5w20 or 5w30 can be used without restriction. 5w20 simply is a "fuel economy" enhancer. 5w30 is SPERIOR protection and DOES NOT reduce fuel economy significantly....you will never notice the difference.
Alexander T.
August 29, 2019
Kia recommends using SAE 5W-30 motor oil (API SM / ILSAC GF-4) for the 2014 Optima when equipped with a 2.0L engine. And when equipped with a 2.4L engine, Kia recommends using 5W-20 oil.
The Questions and Answers on this page are the statements and opinions of their respective authors and not VehicleHistory.com. VehicleHistory.com
does not research or authenticate any of the Answers provided.