Here is a Corvette that put 4500 miles on Mobil 1 5w/30 and goes against all of Patman's preaching. The car had 3 track days on a couple of very tough hot weather tracks and used a UPF44 filter no less! Maybe Terry is right and it's not viscosity dependent?
The discussion is at:
http://forums.corvetteforum.com/zerothread?id=849558
The discussion is at:
http://forums.corvetteforum.com/zerothread?id=849558