Audi TTRS with 1000whp and dark diff oil. Motul gear 300 75w90 is dark after 3,000 miles.

[lamboworld]

I don't drive this car much, maybe 1,000 to 2,000 miles a year. When I do drive it, I drive it hard and it regularly sees very high speeds (160mph+) at racing events.

I change my gear oil every 2 years and I have been using Motul Gear 300 75w90. It was pretty dark and it could have also been this way last time but I don't remember. What is the cause and should I change?

I use this oil in the front and rear differentials.

 

[MolaKule]

Anyone who races or tracks their vehicles should change all the fluids after a 'heat' and especially before any storage.

 

[lamboworld]

Anyone who races or tracks their vehicles should change all the fluids after a 'heat' and especially before any storage.

I don't road race this car, only drag race and street driving. It doesn't see significant heat over long periods of time. It is never WOT for more than 10 seconds.

I assume that you are thinking I am road racing, because changing the diff fluid after every drag race event is crazy.

 

[Fa24wrx]

Id look into hpl gear fluid. They seem to have crazy good gear fluids from what I've read.

 

[SubieRubyRoo]

Id look into hpl gear fluid. They seem to have crazy good gear fluids from what I've read.

Indeed, but if I were OP I’d be asking @High Performance Lubricants directly… not only on which fluid was best, but also change interval recommendations since this is a highly one-off application.

 

[MolaKule]

I assume that you are thinking I am road racing, because changing the diff fluid after every drag race event is crazy.

No, I was taking your remarks at face value.

Visually, Your fluids seem to show a lot of shearing, metal loading, and oxidation-hence my suggestion.

Get a UOA and post it here:

https://bobistheoilguy.com/forums/forums/gear-transmission-used-virgin-oil-analysis.47/