As far as vicosity vs temop. Drag motors don't gain a lot of oil temp. Mine seldom exceeds 160 with a diaper.
Doug
I was going to say something similar for drag race applications. I typically saw between 130-160F oil temp. And some days it took serious engine warm up to get the oil up to 130F.
At 140F, I am thinking a 10W-30 would be about 90 SUS.
At 200F, I am thinking a 20W-50 would be about 100 SUS.
IMO, Pretty close at associated operating temperatures.
And as previously posted, specific brands can vary from each other. I have been using 10W-30 in my drag cars for years. But in my street/strip car, I use 20W-50.
I agree with what BradH said:
From the dual-purpose car perspective, I know my oil gets plenty of heat during street use, including the trips to the track
It wouldn't surprise me if after driving 30 minutes with water temp around 180F, the oil would be around 200F.
