Originally Posted By: CrawfishTails
Originally Posted By: jfang
Results are likely the same because Schaeffer used viscosity grade readacross (VGRA) and baseoil interchange rules (BOI) to read one result (probably on a 5W-30) to the visc grades and baseoil mixes in the other products. Detailed in API 1509 appendix E and F.
Would that apply here if those are Seq IIIG test results?
On that subject of baseoil interchange rules, the base oils span quite a range, as we're talking from Supreme 9000 full-syns: 0w-20, 5w-20, & 5w-30 on through Supreme 7000 semi-syns: 5w-30 & 10w-30 ... Thats 5 different oil blends, all having the exact same test results in 2 areas (visc increase and cam wear). Doubtful this is the culprit here.
Originally Posted By: badtlc
Why don't you research if cam wear is based more on additive package or base oil viscosity? If additive package is the driving factor in cam wear, this falls totally into the realm of believable.
Cam wear and viscosity increase during the IIIG (remember 2 areas of the IIIG test were identical for 5 blends) are very much a function of both visc & additives. Think about it, as boundary lubrication and near-boundary lubrication conditions occur on the surface of the lobes, viscosity governs oil film thickness and additives step in as various basestocks form different tribofilms in combination. Its both!
Originally Posted By: MolaKule
It is possible to formulate to those exact results.
Thank you. Its in the realm of possibility then. Still seems odd you could hit both visc increase & an exact 9.8 micron cam wear for all 5 oils, since the span of products is large. For example, its known to be tough to get a 0w-20 to have great cam wear, and lighter oils like that have different visc increases than a 5w-30 too. You get it. A lot of variables to juggle across 5 differing oils.
Another example, bobbydavro, a tribologist or engineer involved with Castrol recently made a comment on bitog to the effect of how difficult it was to get a ligher visc oil like 0w-20 to pass the tough euro ACEA RNT (RadioNuclideTechnique) cam-tappet wear test, similar to the IIIG, a hot test on a 90's Nissan SOHC 4 cylinder.
Armed with this little bit of knowledge about baseOil exchange rules and MolaKule's opinion that its possible (probable though??) a blender can make 5 different oils with identical (down to the decimal place of micron wear identical) and also hit an exact 130% visc increase in the IIIG across all 5 oils, ...... its now time to ask Scheaffer for an explanation and documentation of certified test results. I can now approach them knowint a little bit about what to ask for. ..... (For those who say those are simply 10 typos, existing for years, or who say wear tests don't matter, they're simply wrong or delusional.)