Interesting Q&A I found on Trackpedia from Royal Purple Below I copied RPs reply on operating temps

Trackpedia: What is the typical operating temperature for engine oil, and when do I need to consider running an oil cooler?


Royal Purple: Typical oil operating temperatures in a naturally-aspirated, liquid-cooled vehicle is 220F. For competition vehicles with oil operating temperatures regularly above 220, or for turbo applications not so equipped from the factory, I would recommend running a oil cooler. For every 20 degrees of oil temperature you see beyond 220F, you reduce the life of the oil by half, regardless of brand or base oil type.

 

From the standpoint of power, a professor I know who did some serious engine research has told me that 225 is the ideal. Anything above that and you start loosing power; anything lower and you're loosing efficiency due to higher viscosity oil. He said this temperature was in a very close range for all oils he tested. He named M1, Castrol, Redline. I'd assume RP would be similar. I know for a fact that when switching to Redline from Castrol, my oil temps dropped by about 10 degrees. The hottest I've ever seen was a hair over 220 while driving on the highway in 100+ heat behind a semi. Obviously, if your tracking your MINI in the summer, oil is going to get pretty hot. Oil temp is very much related to rpm and how much power you are using. It's easy enough to install a temp sensor in the drain plug to see what it's actually doing. I just see too many people install oil coolers when they aren't needed.

 

For those reasons I change my oil (RP) and filter just before a track day and soon there after, also why an oil cooler is near the top of my to do mods. When pushing the limits during a 30 min session at VIR I regularly see oil temps (factory gauge) at or approaching 300 degrees. From what others have told me, this is not unusual for the Mini.

 

Very nice info!

Something I have been trying to promote for some time now, you need hot oil to operate properly. To cold (below 100C) is not good.

I also noticed at least a 10C hotter temp with Castol/MINI oil than when running M1. Strange......