Which motor oil to use after in frame?

[Rawze]

The optimum Zinc level on an engine oil is roughly 1400 ppm. 1200 would be the minimum.

epa has been in a war against this for a long time. Very soon, no oils will have that much zinc.

Quoted from epa documents...

" The useful life definitions for 2004 and newer heavy-duty diesel engines are included below from the CFR. As you can see, the useful life is defined both in terms of mileage and years of operation. For example, the useful life definition for a heavy heavy-duty dieselvehicle is 10 years or 435,000 miles, whichever comes first. In the case of a dump truck, it may be that the vehicle will reach 10 years of operation (i.e., full useful life) prior to reaching the mileage defined useful life of 435,000 miles."

According to them, 435,000 miles is all an engine should last.