[Goldenstate]

I have put Royal Purple gear lube in the rear end of my 1999 F-150 4.6 with surprising results of about 3/4 mile per gallon improvement. I had been running regular Royal Purple in the engine since the first oil change. Recently I went to the high zinc content Royal Purple HPS which they refer to as their street oil. I saw a slight improvement of 1/4 mile per gallon.

The ATF fluid in the transmission is due for replacement soon. Is there any member out there with any experience with what results might happen with a change to the Royal Purple ATF?

A friend changed to the Royal Purple ATF a couple of years ago and never bothered to check for improvement of mileage. Just treated it as business as usual. The Royal Purple website has a claim of improved mileage. Very expensive to do a ABA test with 16 quarts of expensive ATF, so was curious as what I might expect in improvement.

Goldenstate