2014 Kia Optima EX
I have a 2014 Optima EX that I had replaced the OEM plugs at 97,000 miles. I used Autolite Iridium XP plugs and they seem to be working great. This is the first time I've ever used iridium plugs. My car now has 151,000 miles on it. Should I change out my current plugs since they already have 50,000 miles on them, or will the iridium plugs last till I reach 200,000 miles or longer? Thanks!