How much Zinc in an ACEA C3 diesel engine oil??

[weasley]

Just to try and wrap this up; none of the engine oil performance categories (API, ACEA) have any zinc control limits. Only in recent years have there been ANY chemical limits and, where they are introduced, they are on phosphorus (as well as sulphur and sulphated ash). Some have only a maximum limit, a few include minimum limits.

ACEA C3 has a phosphorus limit of 700-900 ppm. You may be able to imply zinc limits based on that, since Zn ratios tend to be fairly well-defined, but different ZDDPs have different ratios, so without knowing exactly which is in use in any given formulation, you'll get nothing more than a best guess.

 

[weasley]

PS: the only specifications I ever came across for diesel engines with a zinc limit were the old LMOA railroad engine oil generations, which included a 10 ppm maximum (yes, maximum) for Zn. This is because these oils were used in GM-EMD 2-stroke diesel engines that used a silver-plated wrist-pin bearing, and ZDDP corrodes silver very readily.

So, even with no zinc in their oil, these monster engines managed to haul huge loads all over the USA and beyond. And the same zinc-free oils were also used in GE, Bombardier and other engines of a more conventional 4-stroke design.

 

[Bodensee]

I hijack this thread as it's old and have related request for UOA results from boss man.
What I need is UOA results showing 2 OCI's or more, where a normal HDEO or car diesel oil was used, followed by a C3 (DPF approved) oil of the same viscosity and preferably from the same company and type (Similar add packs).
I think senior manager concerned there is still no answer to low Sappers (Low Zinc) causing increased wear metals just because bunch of "Go Greenie" folks insist of DPF lasting until end of world.

I have nasty idea that both Castrol and Mobil telling whitish lies from marketing that C3 is backwards compatible with B3 and B3. Running big rig test at work that will prove if written statement from Castrol R&D man correct or not, BUT UOA et al will take another year to reach statistical significance. Involved in bet with other engineers that Castrol man is going to get fired! Skyship has only put 100 Euros in the pot, I got drunk and put a thousand in. Company pot total is over 5K and still rising.

The API and ACEA tests are none too good, because they are done with clean oil at start and no real world contamination factors checked. They do prevent bad oils being sold, but are of little use in finding a good one. The Germans are correct, that although they use test rigs and computers, they have a whole range of vehicles driving around the EU doing the same jobs with same drivers, some with and some without C3 or new fluids or oils. The results are sometimes very different and I don't think that the majors found an economic answer to being forced into making a low Zinc oil.
I have half a shirt at evens on Delvac or Rimula winning the UOA truck stakes, then we start new betting on strip down results, although not many will be willing to bet against a full particle counting summary!