RL Shockproof Heavy, 3.6k mi OCI, 49k mi '13 CTS-V

[Emperors6]

All mileage is in kilometers not miles. Switched to RL 75W90 for winter since RL recommends not running Heavy in freezing temperatures. The previous fill was the same.

The report below has 4 track days on it with no reported diff overheats to 300F since sessions were kept short. The car has no diff cooler. I am going to add a diff cooler for next spring/summer.

No idea about the high insoluble content above except I drove the car harder and the LSD had to work much harder at the track. Should I be worried?

 

[MinamiKotaro]

37 cst?!?!

 

[Emperors6]

Their marketing material says: "Film thickness greater than an SAE 75W250, yet low fluid friction like 75W90"

 

[aquariuscsm]

Does your car spec 75/80W90? From looking at gear oil uoa's,I'd give Amsoil Severe Gear in the spec weight a try.

 

[Emperors6]

Yes, my car specs 75W90, but the OEM stuff thickened after 13k miles. So, I switched to RL. Any specific reason for recommending Amsoil over RL? I'm not exactly comfortable with their marketing structure and cherry picking tests.

 

[aquariuscsm]

Based on the uoa's here,Severe Gear always has the lowest wear metals. Your car specs 75W90,fill it up with Severe Gear 75W110.

 

[Emperors6]

Even with the diff cooler? I think then I should just run RL 75W90 then. I'm not even sure the Shockproof was necessary, but it doesn't look like it harmed anything.

Also, I haven't run Amsoil Severe Gear before.

 

[FlyNavyP3]

Originally Posted By: Emperors6
Even with the diff cooler? I think then I should just run RL 75W90 then. I'm not even sure the Shockproof was necessary, but it doesn't look like it harmed anything.

Also, I haven't run Amsoil Severe Gear before.


I think your plans for a diff cooler and RL 75w90 are right on the money. If it was my car that's exactly what I'd do.

 

[Rand]

The insolubles are from the "shockproof" part.

Thinner will run cooler.. as long as you keep it under control so it provides enough protection.

So I like your plans. You could always buy a quart of 75w140 and blend it for an inbetween thickness.

 

[Emperors6]

How come the insolubles weren't as high in the previous fill? It was the same oil.