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Old 09-12-2019, 01:23 PM   #15
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Join Date: Feb 2016
Location: Portland Oregon
Posts: 7,824
Re: Oil confusion, please help!

Originally Posted by bigmac73 View Post
That is not good.... do u have some documentation to support ? I might have to swap to royal purple
Does the oil have a API designation? If so they have removed the majority of ZDDP. The standards changed so in order to maintain their rating they removed the zinc. Zinc kills catalytic convertors and now that diesel trucks have them the zinc had to go.
Here are some links if your interested.
Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help.
1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F3 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo
If it breaks I didn't want it in the first place
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