I open track my '00 LS1 Camaro. I don't have an oil temp gauge on my car but others have reported temps approaching 300 F in this application. Temps that high scare me, so I have been using M1 15w-50 as a precaution. Is this too high a viscosity as some on other boards claim? I'm concerned about longevity and I'm willing to sacrifice a few hp to achieve it. BTW did a search but couldn't find anything this specific.