Pinto Car Club of America

For good up to date tech on ZDDP in oil look at  http://www.ctci.org/gilsgarage/EngineOil2.php 

Seems like adding ZDDPlus to 5 quarts adds about $1.75 per quart. Thus from the article I'd be incline to say that the Rotella T is the better deal.  Thanks for posting the link. Often times a lot of what people say is urban legend, old wive's tales, and opinions thus it is nice see actual lab results.  With roller rockers in the Pinto it is not much of an issue, but my other cars is a concern. At least one does have the Rotella in it. And since I got other "current" oil for next to nothing the $7 for ZDDPlus would not be too much.

I'd assume that synthetic oil means nothing for the ZDDP issue?

I run off the shelf oil in all my street vehicles with stock cams, I put 80,000 on my dually with no wear on the cam, problem starts when you get into hotrod cams that require high spring pressures, that's when you need the ZDDP, off the shelf oil is not made for that.

Synthetic and ZDDP are two different animals for two different purposes and have nothing in common with the other.