For any of guys out there who have a flat tappet camshaft in you race car, we've posted the results of a 6 hour cam and lifter wear test comparing the new API SN, the new GM dexos 1 and the Joe Gibbs HR-4 on our website. Here's the link...http://www.joegibbsdriven.com/trainingcenter/tech/weartest.html
These new oils are just fine for modern daily drivers, but if you have an older style engine with high valve spring pressures, you might want to stay away from the modern motor oils.
Lake Speed, Jr., Certified Lubrication Specialist, Joe Gibbs Racing