[AMC-list] ZDDP in oil - do you need it?

[Frank Swygert <farna@xxxxxxx>]

I found some "Accel" branded oil specifically stating "for pre 88 cars". It has the "API SF" rating. I think I found it at a local Wal-Mart. I noticed that it was made by Warren Distribution, Inc., a US company with facilities in West Virginia, Iowa, and Alabama. I don't think they refine oil, but they buy base stock from others then formulate (add additives and viscosity modifiers) and package their own brands and a lot of "house" brands. "Accel" is one of their brands, another is "MAG-1" (http://www.wd-wpp.com/index.html).

I sent and e-mail to Wrren when I found the SF rating and asked about using it in our older flat-tappet cars. He replied that it really wasn't necessary for a stock vehicle, and the he would personally not run ANY older rated oil due to better anti-foaming, detergent, and other agents in the current SM rated oils (and beyond). I told him about wiping cams in newly rebuilt engines, and he did mention that a high pressure or "break-in" additive was best for the first oil change or two, but after break-in a stock engine didn't need anything other than a modern oil and regular changes. No additives at all. He also stated that high performance engines using higher than stock valve spring pressures may need the additional protection of specific racing oils. All racing oils that I know of have ZDDP and/or other high pressure lubricants in them, and are clearly marked "racing" or "for off-road use". 

I had a similar discussion with a big Atlanta AMSOIL distributor. It seems that the lower levels of ZDDP are only required by law for the most common oils -- 10W-30 and lower viscosity. Anything higher (either the first or second number -- 15X-xx or 10W-40 or higher) isn't affected by the law. Heavier (than 10W-30) diesel and racing oils MAY have more than 800 ppm of ZDDP and/or other high pressure lubricants in them... or rather they aren't required by law to have low levels. 

I think the assumption is that most vehicles using those weights of oil are out of warranty or off-road vehicles, or older diesels that require ZDDP. Sounds like a reasonable compromise between the auto industry and EPA, as even the new diesels that have cats on them are spec'd for 10W-30 or 5W-xx oil. 

In summation: it's like the old leaded vs. unleaded fuel debate sparked when lead was eliminated. There is some cause for concern, but only when rebuilding or running higher than stock valve spring pressures. I'm sure there's a "max amount" of spring pressure, but for the most part "stock" will do. 

------------
Date: 14 Jun 2009 13:11:27 -0000
From: theamcguy@xxxxxxxxx
Subject: Re: [AMC-list] zmaxx??

zmaxx is a chlorine based lubricant.  Chlorine is an excellent extreme
pressure lubricant but has some other deficiencies.  The stuff you want is
zddp http://www.zddplus.com/  I know the guy who developed it and he spent a
lot of time research and development.  What this stuff does is bring the
modern day SM oil to pre 1988 SF oil which is what the flat tappet cams need
for protection.  At the same time you get the modern detergent pkg in the SM
oils.    

--
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)


_______________________________________________
AMC-list mailing list
AMC-list@xxxxxxxxxxxx
http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com