Mistake with my 2015 KIA Optima 2.4 liter

Jul 21, 2022
Hello. I changed the ATF in my 2015 KIA Optima 2.4 liter 6 speed automatic. I didn't realize that had I changed it and refilled it with Sp-III ATF until I had already filled it, test drove the car and did the level check. When I threw away the empty ATF containers I discovered it was ATF SP-III instead of the SP-IV the book calls for. So I did three more fluid changes with Valvoline MAXLIFE SP-IV with about a 15 mile drive between the changes. Do you think I will have any problems in the future because of this? I can do more fluid changes again if you think I should. Can't believe I did this. Thanks for any advice.
Jun 15, 2010
You’re probably fine. It’s not like the fluids are incompatible with each other. SP-IV is synthetic and SP-III isn’t. That’s really the only difference, along with the inherent characteristic differences between synthetic and non synthetic atf.