Why pay $$$$$$$ for AMSOIL???? The only approved oil for the 4R100 has always been Dextron/MerconIII , only recently has Ford all of a sudden said it is okay to run MerconV, even though it strictly warns against this in your owners manual. Ford has been asked by thousands of us why it is now okay to run this Mercon V and no response. Some want to tell you the Mercon V has been reformulated to work in the 4R100, this is a bold face lie. Many have researched this and no reformulation has ever took place. Think about it, how many 4R100's are still under warranty? Not many, the Mercon V isn't going to kill your trans overnight, it will take quite awhile to ruin the seals in the trans, buy this time all warranties will be expired and Ford can make a fortune rebuilding tranny's. Think they won't do that? Look at how much they charged for a CPS for many, many years. Mercon III/Dextron hasn't been made since June of 07, once the supply is gone it's gone. Could be a year, could be 5 I don't know. I bought 4 cases and since I only put 12K per year on my truck it should last me awhile. The only time I recommend synthetics is if you are towing heavy, alot and see tranny temps above 200-210 on a reg basis, if you don't use your truck this way and see these temps reg old Dino oil will do just fine. Dino oils have come a long way, so don't fall for all the hype on synthetics, especially the claim they lower tranny temps. I fell for that one and proved it is false!! Synthetics are good for certain conditions, but the average PSD owner doesn't need them.
NCH
