I switched mine over to Mobil 1 ATF at 6K. Then I changed it again at 26K and again at 45K, but that time I added the friction modifier to it. I know this is excessive, but thats just the way I am. It takes (3) quarts of ATF, which when using Mobil 1 ATF, costs about $15.00, plus the additonal $10.00 my buddy charges me to change it out. Cheap preventative maintaince