I think you have to look at how many people report going over the 100,000 mile mark without problems and issues using the 5-20 or the 5-30 oils. It took me forever to move from the 20-50 oils in the late 80's, and the first F-150 I had with the 5-30 oil I just couldn't believe it would last on that "thin stuff".

But survive it did! All my family's Fords are running 5-20, which includes the Cobra with S/C - just to question the need for higher weights with the turbo, and all seem happy enough.

It used to be that we were happy to get 100,000 miles, now our bar has been raised to expect "at least" 150,000 so the manufacturers must be doing something right, yes?