Originally Posted by dkmura

Regarding the mileage/time factor, I had the MT85 in my T3 SCCA racecar tested by Blackstone this spring. I'd left it in for three years and wanted to see how it tested. Plenty of life left (low TAN), but iron wear was a trace higher than their universal averages. After talking with them, they suggested pulling another sample in 2018 and comparing.

Keep in mind, this tranny gets used extremely hard during race season, but rarely sees much mileage outside of that. Probably 1,400 of the hardest miles on any Z tranny out there.