Kris01 wrote on 04/22/15 at 20:02:16:I forget how much zinc (in ppm) is in Rotella T. It's listed on the forum somewhere. However, the consensus here is that it is a little low compared to what oil used to be. The prevailing thought around here is that 1100 ppm is a safe amount. I add 2 ozs of Redline to 1 gallon of Rotella T.
Adding 2 oz. of the ZDDP additive is as much as you should be adding....don't add more than that. I found a report that showed adding more then 1,400 ppm of zinc actually increases wear.
Dave wrote on 03/11/15 at 08:48:02:I am sorry this has turned into an oil thread....but here is some data I found:
And keep in mind for comparison with the oils below, that earlier oil industry testing has found that above 1,400 ppm, ZDDP INCREASED long term wear, even though break-in wear was reduced. And it was also found that ZDDP above 2,000 ppm, started attacking the grain boundaries in the iron, resulting in camshaft spalling. So, no matter what zinc fans might “believe”, there is such a thing as "too much of a good thing".One fellow compared it to adding a couple of teaspoons of sugar in your COKE.....not a good thing!
It came from this document....which also has a lot of information for which oils have good reports for low wear. (Remember....these may not be oils suitable for wet clutches - and that a lot of the racing oils do not have the additives for normal oil change intervals...racing oil is often changed after a few runs).
http://speedtalk.com/forum/viewtopic.php?f=1&t=35836