do a google search on the 540rat guy before you trust him blindly...
He even admits that his testing does not simulate what's going on in a running engine.
Yep. The dude's a "Mechanical Engineer" (which is evidently a proper noun), not a tribologist. Take what he says with a grain of salt. Regardless of what he says, ZDDP is a good oil additive and oils with high ZDDP-content should be used during engine and cam break-in. Years ago, we ran some tests to see how much ZDDP some commonly-used oils had in them. The results are posted
here.
That's an older list so a lot of those levels might be less now depending on the intended application of the oil.
The best way to KNOW what the zinc and phosphorus levels are in a particular oil is to buy a quart and head down to the nearest Kenworth type dealer, buy an oil sample kit and pour some oil in it and send it off. Costs about $25 +/-.
Bobistheoilguy is a good site to look at new and used oil analysis reports. Most of the 15w40 diesel oils are still in the 1000 ppm range on both. The 5w40 diesel synthetics seem to have closer to 1100 ppm than the conventional oils on reports I've seen which I found a little odd.
Kevin
