What is the best replacement for Kia/Hyundai/Mitsubishi SP3? Mobil 1 used to carry the "recommended for" verbiage and it has since been removed. Mobil has said a reformulation did not occur and internet lore says Mobil was threatened by Kia/Hyundai. Do we know what makes SP3 so special that it does not have any approved aftermarket replacements? I am wanting to use Mobil 1 in my 2010 Kia Optima. The car has a warranty until 60K and I have 42k now. I really am not overly worried about the warranty aspect. I have read where Mercon V is the closest formula. Then I read where ATF +4 is the closest formula. Some people say that Valvoline Maxlife is the stuff to use. The trans holds around 10 quarts and I have done two drain/fills (With SP3) which replaced about 9 quarts. I had planned to do yearly drain/fills but I have read so much that states SP3 is a poor fluid. Am I safe with yearly drain/fills or do I look for a synthetic replacement?