Thank you everyone who has offered suggestions. My reason for wanting the Mobil 1 is that I used it several years ago to do a drain and fill on my 4T65E tranny and it was a miracle worker for stopping the shuttering I was having on take off from a stop which was worse in summer but seldom if ever occurred in Winter months. It's only my theory but I really feel that this synthetic replacement for the old DEX III is great at holding viscosity specs. The last fluid that the Mobil 1 replaced was DEX 6 and I'm convinced that in spite of what GM says about backward compatibility, the DEX 6 lower viscosity numbers cause issues (or can cause) with the trans' functioning. FYI, this trans has received strict fluid changes since new with filter changes as well. It was driven gently by its elderly prior owner and while I'm not a senior citizen, | must admit I drive like one!! I have no specific loyalty to Mobil in general and I agree with all of your postings that there are many great AT fluids out there and motor oils as well. (I've used Mobil 1, Castrol, Pennzoil, Kendall, etc. for my crankcase and found all of them great products) I guess that when I find something that works and I'm maintaining my only car, "if it ain't broke, don't fix it" is something that guides my decision making. I will check with CT and PS and see about getting some ordered for my next drain and fill.
