Premix at the pump

[classicauto]

IMO anything will be better then putting engine oil into the chamber with the stock MOP.

I used to run an off brand back when I had a few close successions of engine failure and to be honest I noticed no difference between engines I've ran on amsoil (current ones). There's probably differences between the two with additives and whatnot, but both are much MUCH better suited to being burnt in the chamber vs. 10W30 or whatever is in your oil pan. Either one will be leaps and bounds ahead of stock in terms of carbon buildup on the internal parts.