Engine oils see much higher temperature extremes than what tranny fluids normally sees. Look at the life cycle normally given for tranny fliuds. Earlier in the year, my tranny started to shift hard. I changed out the fluids using the new Valvoline Max Life ATF fluid. Now the tranny is working much smoother with much improved shifting characteristics. My tranny had about 80,000 miles when I changed the fluids.

If I was to use a synthetic ATF, it should be introduced on a low mileage transmission. I would be concerned with seal leakage on a higher mileage transmission. The Max life has additional additives to recondition the seals within the transmissions. Unless you're exposed to abnormally low or high temperatures extremes, synthetic in the tranny is a waste of money.

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groundhawg