Ok Ive done the searchs and havent found my answer. I have an 04 4x2 auto. 3.3l. Can I do drain and fill on the tranny by adding sythetic to regular ATF. Then drive for 15 min. or so and do another drain and fill. I saw where people reccomend this method rather than flushing but not with mixing Mobile1. Doing it a third time would assure your mix was mostly synthetic. Am I wrong? My X has 19000 miles. I have had bad experiences in the past with Jiffy Lubes and dealerships and would rather do this myself. Would appreciate any feedback, Thanks. Hoopster