ZDDP and Oil

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528i-1981
Posts: 175
Joined: Wed Feb 07, 2018 5:50 am
Location: Boston North Shore, MA

ZDDP and Oil

Post by 528i-1981 » Fri Jan 25, 2019 4:22 pm

Oh yeah I’m going there. Let’s party like it’s 2006 on mye28.com.

Looking forward to the summer and reading up on what’s involved in a top end rebuild, should I need one (179K miles, last one at around 98K, tick tock). And then I discover the ZDDP issue and how at least during run-in a ZDDP additive is called for with today’s zinc-depleted oil formulations. Easy enough - can do.

My question - does anyone regularly use a ZDDP additive in their M30? This issue was everywhere a decade ago with the E28 crowd (as well as vintage American OHV performance car fans) and now it’s crickets. I can’t even find a reference to ZDDP on FF. I don’t think anyone here ever caught the bug.

My car has evidently always used Castrol GTX 10W-40 year round but admittedly has seen far less action over the last decade than it did during its first quarter-century when oils were formulated with substantially more ZDDP.

To ZDDP or not ZDDP. That is the question.

-Eric
(oo=00=oo) Eric
1981 528i Manual

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Mike W.
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Location: Sonoma County

Re: ZDDP and Oil

Post by Mike W. » Mon Jan 28, 2019 12:51 pm

ZDDP is still a big deal on Mye28 and other places. I've never thought it was that big a deal personally, although my M30s haven't seen many miles in the past decade either, although my E28 did until '09 and no visible wear on the cam. 10-40 is a bit then, but I guess with your location you don't exactly see how summers and don't want to do oil changes by the season, and I can't say that I blame you.

Ironically ZDDP was removed because it's hard on catalysts and in the quest for better MPG automakers (emphatically including BMW) started using low tension rings and just accepted increased oil consumption as part of the deal.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter

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