[Healeys] Syntec Oil

[Dave Russell]

Gary,

Not quite sure how to word this.
In the instance of Valvoline VR1 20-50 "Racing", the container shows 
that it is rated API service SM.
SM in itself would indicate reduced ZDDP, yes, no, or it depends on the 
particular viscosity of the SM?

Are you saying that although it is rated SM, but the 20-50 would not 
likely be used in a "modern" engine, it "might" contain more ZDDP than a 
5-20 SM rated oil?

In other words, do SM rated oils  have different amounts of ZDDP  
according to their viscosities/likelyhood of being used in a modern 
engine?  Does it mean that not all oil viscosities of  SM  rating 
contain reduced ZDDP?

The oil companies published information makes it very hard to find the 
answer. Worse - The oil formulations  seem to be changing on a near 
monthly basis but the published info is quite old in some cases.

I think I will continue to add a pint of GM EOS to my oil changes. To 
me,  it's not worth taking the chance.

Regards,
Dave Russell

Editorgary at aol.com wrote:

>>on the MG list and 20W50 is NOT used in modern cars AFAIK. They all require a 
>>much lower weight synthetic oil. Hence it is quite plausible that an oil 
>>company might be putting different amounts of ZDDP in their different weights of 
>>the same brand of oil.
>>Just the facts, ma'am.
>>Cheers
>>gary