andy-gts

I use amsoil 20 50 z rod and no problems, for racing I use Greg Brown recom of torco racing

polecat702

Dave: I'm amused by the comments regarding V-Twin engines and higher zinc levels in the V-Twin formulation.

Harley Davidson has had roller cams in every OHV engine since the 1936 Knucklehead.

hacker-pschorr

I think this is coming from the "more is good, even more is better" mentality.

I don't know what the correct answer is, if you do 20 searches on this topic, you can find 20 different answers.

I like to simplify these problems. What was the ZDDP level in motor oil before the EPA (or whatever governing body) got involved in a quest to save the catalytic converter?

As far as I can find, 1100 - 1300 is the common range. So in my opinion, that is all our cars need.

Will more be "better"? I personally believe no, at some point you reach the point of diminishing returns. This is simply my opinion.

I think the ZDDP debate is kind of a moot point since I have yet to find a 15w-50 or 20w-50 with levels lower than the "old" standard.
The reason is, the new ZDDP levels apply to thinner oils designed to increase fuel economy in newer engines.
Other than a few BMW's that call for 10w-60, I don't know of any modern engine that calls for a weight higher than 40, while the majority are designed for 20 and 30 weight.

Even on the track, my friends race Corvette's run 5w-30.