Originally Posted By: ExMachina
Originally Posted By: Garak
Originally Posted By: MolaKule
How do you know a so-called "thickener" like STP will raise the HTHS?
You mean, it might be akin to a garbage, low HTHS 10w-40 that concerned GM back in the day?
I guess STP Oil Treatment, used as a thickener, may destabilize the pudding chemistry. And yes, I was assuming STP would raise KV100 & HTHS both.
This is going to be harder than I thought. Shannow suggested using a straight 40 oil, which might be better. However, what if one kind of went in the other direction and made the sump 10% M1 Racing 0w-50 (additive rich) mixed with a new GF-6B Mobil1 ? There must be a way to raise HTHS just a tad, up to like 3.0 and still retain the cutting-edge boundary lubrication performance of the new GF-6B low-HTHS oils.
This was my original point that you contested (sorry I took the long weekend off to enjoy the last sun of summer).
GF-6A will be formulated with high performance additives and meet the higher HTHS requirements.If you want an oil with higher HTHS viscosity and the requisite matching additives then you should choose a GF-6A oil.
GF-6B will be formulated with high performance additives and meet the lower HTHS requirements.If you want the benefits of fuel economy from lower HTHS oils, then you choose a GF-6B oil.
Both parts of the new Category (A&B) will be held to the
SAME standards when it comes to wear protection. Incidentally this is also going to be similar or better levels of protection to the current category (at least that is what we are hearing from the groups developing the new test protocols.)
Choosing between A&B is the only difficulty you will have. You don't need to mess around mixing things into a GF-6B oil which may or may not give you any extra benefit. For sure you will be killing the fuel economy advantage... I see no advantage for improved protection as both will be held to the same standards. If you want higher HTHS, then choose GF-6A.
Of course this is all an academic hypothetical question until at least another year or so when the category tests are finalized, then we will have a better idea of what the formulas for these categories will look like.