- I have a 2013 Kia Optima SxL, which spark plugs would be better? I live in the Midwest so winter is very harsh, I'm not sure if that plays into anything. I was looking online and saw NGK 1422 and HKS M45XL. Which one would be better, or is there something else I should get instead. I do not have a tune and do not plan on getting one.