After seeing the 1300 PPM of
Zinc in the M1 15w/50 I think I'll keep it in the crank case for a bit longer. I hate to waste 10 quarts of
oil anyway... I still ordered 10 quarts of the Joe Gibbs 15/50 HR
oil for the next
oil change though. After that, due to Joe Gibb's exorbitant pricing, I'll return to Mobil 1's 15/50.