The beauty of this oil is, I truly believe a lot of cars on the road today would show better engine wear numbers with a higher 30 to low 40wt oil. An engine such as my LT1 or the LS1 engines too, would benefit from it. Anything that has a looser clearance like this, and engines with a bit higher miles on them too. But a lot of the 10w40s out there end up being a bit thicker, in the 14 to 15cst range, so they end up just hurting the fuel economy while not really protecting better.
The trend with a lot of oils, such as Mobil 1, seems to be to formulate it at the lower end of the 30wt scale. This works well for new tighter clearance engines, but I think these oils in higher mileage and looser clearance engines end up sacrificing engine wear for fuel economy.
This is why I want to do my viscosity test this summer, mixing Schaeffer 15w40 with 10w30 in a 50/50 ratio, to see if engine wear is lower in my car with an oil that is in the higher 30 to lower 40wt range (12-13cst specifically) Who knows, maybe I'm way off base, but I have a strong gut feeling I'm correct. A hard driven car like mine just needs a little bit more "cushion" in there. And with these slightly thicker oils, the HTHS goes up too, which is definitely a good thing.
I think Amsoil agrees with me on this one too, since their 5w30 and 10w30 are formulated at the top end of the 30wt. I know this is partially done in order to keep it in grade for longer intervals, but I also believe they are thinking in terms of engine wear even for those that do shorter drain intervals too.
[ February 19, 2003, 11:19 AM: Message edited by: Patman ]