Looking for some info on changing my trans fluid on my 2020 Sorento 3.3 with an 8 speed tranny. I want to do the drain & refill method and need to know how much fluid to purchase, thinking 2 gallons will be enough?? Also what fluid to use? Owners manual states KIA fluid or any meeting the ATF SP-IV specs. Valvoline MaxLife Multi-vehicle ATF says it meets this spec. Has anyone used this AFT and would recommend it? Any problems with it mixing with the remaining KIA ATF left in the trans?