Quote Originally Posted by AndrewANZEsuspension View Post
Part of the issue is the 10w-30 has fewer modifiers than the 5w-30. The base stock of the 10w-30 is closer to 30w so it needs fewer modifiers than the base stock of the 5w-30.

In my previous job which was all Porsche track cars we used 15w-50 and 20w-50 in the older engines with larger clearances and especially the older turbo engines. We always used race oil (not street oil) and it was carefully lifed (6 track days for N/A cars and 4 track days for turbos.

Before I moved to ANZE Suspenesion we were running the newer N/A cars with Motul 300V 5w-40 and the turbo cars with Motul 300V 15w-50. Using the Motul 300V race oil we found a small drop in temp but a significant improvement in oil consumption across the whole customer fleet. This oil is not great for street use because it does not have all the same detergents as street oil but it was perfect for track car applications.

Andrew
ANZE Suspension
wow, welcome to the forums!!! hell of a way to contribute on one of your first posts, lol.

what would you recommend for a car running 90% street / 10% track in warm climate only (Florida)? How does the Motul compare to AMSOIL?