Used this oil twice in the front diff on my Denali 4WD. Works well, I flooded it with this material in early 2016. About 6 months ago I noticed that my diff started howling at high RPM so I dumped it with the same stuff about a week ago and it was quiet again. I won't complain about durability as I have 4WD, ride hard, put 30,000+ miles between intervals and my Denali achieves that on the run. Next time I plan to use Redline Heavy Shockproof just for experimentation, but unless I'm blown awayβ¦