z driver 88t

I always run M1 15W50 due to the higher claimed Zn/P levels than most other "off the shelf" oils:

http://www.mobiloil.com/USA-English/...duct_Guide.pdf

However a recent post over on bitog has me concerned about the current formulation which shows lower P but much higher Zn.

http://www.bobistheoilguy.com/forums...95#Post2687395

I realize the post on bitog was from an Australian source and oil companies have different formulations in different parts of the world, but I'd love to see a current UOA on Mobil 1 15W50 if anyone has done one within the past year just to see how it compares to the info provided by Mobil 1. No recent UOAs or VOAs were posted for M1 15-50 from what I could tell.

Kiln_Red

Mobil 1 15w-50 ZDDP is 1300ppm

z driver 88t

Well, maybe. Thaat was true back in 2007 becasue I found a VOA on bitog that showed a formulation that met the specs on Mobil's prioduct sheet.

But if you look at this UOA you can see that it is either no longer correct or their quality control is poor or the lab analysis is off. One of those statements must be true.

This is a UOA of 15W50 from US spec Mobil 1 from August 2012 shows Zn and P about 10% lower than claimed on their product data sheet. Enough to have me a little concerned.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2734988"]http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2734988"]http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2734988

Here is one from an M5 board also showing Zn and P to be about 10% low:

http://www.m5board.com/vbulletin/e39...l-1-15w50.html

I'd just like to see it in a UOA/VOA. Have you run one through Blackstone recently? Or is your statement based purely on Mobil 1's claim?

tveltman

I would only believe a 10% difference if you have many analyses in the past that show variation much less than that. In other words, if your past analyses are all within 1% of each other, and then this one is 10%, I might be concerned. I suspect that they are using an extraction method followed by ICP-OES/AES (Link to the wiki). While the analytical method should be very accurate, the extraction process is bound to be much more variable, so there is likely to be some error in that step's repeatability.

You can test this (if you want to spend the money) by saving one bottle of oil (completely unused) that you regularly send a sample of along with your oil for analysis. That way you have a stable sample which you can use to measure their variability (this is a separate control from VOA). The composition of the oil won't change just sitting in the bottle, so any variation is due to their process errors.

Also, do you have a link to the manufacturer specification sheet? The specifications will have a tolerance on them, and maybe 10% is their stated tolerance.

polecat702

If your that worried you can run 20/50 Harley oil. It's 1600 phos, and 1700 zink, in their syn oil. BTW, Harley has used roller cams in their OHV engines since 1936.