Okay, before everyone groans, and says "search" and "read the faq" let me just say I did that already. My question has a twist.

Who out there drives in autocross events and road course events?

I would be interested in opinions on what you guys are using for oil weights and drain intervals in your engines under these conditions. Personally, since it's been cool around here, my last several events have been run on Mobil 1 5W-30 that has been in there for 6200K so far. Shortly it will be drained and sent for analysis, but I'm curious what experiences others have had while pushing the cars a little.

you should have posted this in the autox forum...

If you race in a sport time that a thousandth of a second counts, then you need every single ounce of power you can get. Since you mentioned that it is "cool" at your area, then I think 5w20 will be good because it has a very low viscosity, hence free revving engine.

If you cannot do a switch to 5w20, you should try 10w30 instead of 5w30. This is because the 10w30 has a smaller gap than 5w30.

Thanks for the input. After reading Bill's spreadsheet several times, I think I'll stay away from 5W-20. I am looking for a compromise between max power and oil longevity. I do not really compete in track events, just autocross, and that extra edge the lighter oil might give me isn't worth the potential downside to the car, as it is my daily driver. If it was a dedicated track car, it would be a different story. Thanks again and Happy New Year everyone!