xW-50 still higher ZDDP limit than <xW-40 API SM?

[SuperFast]

just read this, im in the right place to confirm or disprove:

The EPA sets a limit to ZDDP use. That limit has not changed in a few years, and will eventually be reduced to zero. The EPA rules allow motor oil viscosity above 40 weight a slightly higher ZDDP limit. That limit has not changed.

So . . . that's right . . . Our 50 weight oil has more ZDDP than our 40, 30, and 20 weight oils. That statement has always been true. And the ZDDP levels in our motor oils have always been at the EPA limits for the various oil weights.

Is this true or false, with API SN, SM and SL ? will help me to know, im sure i aske din the right place.

FWIW, i founf it in a forum analyzing the statement of Mobil 1 15W-50 from 2007, if its ok the link is here, its a forum discussing the Mobil 1 its only the one post, i hope this is ok http://www.advrider.com/forums/showpost.php?p=4482309&postcount=7

Thank You

 

[A_Harman]

Technically, it's not the EPA that sets the limit for zddp content in oil. It's the API, and that only applies if the oil manufacturer wants to put the API service symbol and starbust emblem on the bottle. Realistically, the EPA is probably twisting the API's arm to lower zddp limits, but they seem to have leveled off with the SN specification. Oils 30-weight and below are limited to Phosphorous content in the range of 600 to 800 ppm. 40-weight and above are allowed higher P.

 

[dakota99]

Any oil rated GF-4 or GF-5 is subject to the zinc / phosphorus limits. GF-3 oils are not. That's why mobil 1 0w40 is SM but has 1000 ppm phosphorus and 1100 ppm zinc. It's GF-3 rated.

Rotella is also the same way, SM oil but with more adds.

 

[chevrofreak]

You need to stop obsessing about ZDDP. Your little 2.8 V6 is not a high performance engine that needs high performance oil.

 

[A_Harman]

Don't listen to chevrofreak.
Your car was built when 1200ppm of zddp was normal in passenger car motor oils, not just racing oils.
One commonly available oil that has that much zddp is Valvoline VR1. I recommnend the 10w30 grade for your 2.8.