what oil is safe?

I have a friend who works at Exxon/Mobil in the lubricates area (basically a mechanical engineer who specializes in industrial lubrication).

Anyway he looked up all of the ZDDP values for the MOBIL 1 product line and informed me that the two Mobil 1 versions of 15W50 oil (extended life and ?) both have around 1200 ppm of ZDDP. The Motorcycle oils have even more, but cost like $8-9 a quart. The remaining Mobil 1 product line are all SM products so they have lowered the ZDDP content of the oils, like everyone else in the industry.

I plan on switching my engine over to the 15W50 Mobil 1 , but I am still looking for a local source for it in gallon containers.


I believe if you do the math you will find that one small container if STP will not raise the ZDDP levels in 5 quarts of SM oil to the levels needed for a HP flat tappet camshaft