Originally Posted By: Jooksing
Sorry. I am still learning. Please correct me. -not being sarcastic
My limited understanding is based on what I have read so far.
It varies WILDLY grade-to-grade.
I wouldn't say you are "wrong", as in one sense, you are correct that some of the oils Mobil presently produces, using less expensive bases, are indeed cheaper to formulate. On the other hand, there are a number of oils with significant portions of PAO in them, at least based on the limits of what we can glean from the MSDS sheets, which was the main ingredient in the pre-dispute era Mobil 1 product line.
PAO is expensive, but then so are POE and AN's, and all of these bases exist in Mobil's product portfolio through XOM Chemical. While VISOM, which is Mobil's "Group III+" base, is cheaper to manufacture than PAO, Mobil is one of the largest manufacturers of PAO on the planet, and do use it, in varying dose levels, in their products.
VISOM was, when it was developed, designed to be nothing more than a high-VI intermediate, bridging the formulation gap from a product line that was PAO-based to one that would use significant amounts of GTL base oil, which is also less expensive to produce, but takes massive investment to bring to market in any volume, something that Shell has demonstrated aptly with their Pearl facility. The idea was to go from PAO, to a PAO/VISOM blend, a ratio that would vary depending on formulation requirements to meet performance targets, to an eventual PAO/GTL blend.
When Mobil cancelled their massive GTL plant in Qatar, the general view on here was that they'd just soldier on with VISOM, however that has not been the case, as M1 0w-40 "FS" appeared, having a significant portion of its base mix as FT-derived (GTL) Group III in it, indicating that Mobil was indeed using GTL. Are they purchasing it from Shell, or have they managed to convert or expand one of their many existing gas plants to produce this base? We don't know, and Mobil's websites are absent of details. We do know this was the eventual goal as provided in their roadmap however, and forging ahead with it would indicate that they've managed to secure, via production or procurement, sufficient GTL to make that happen.
The BBB dispute with Castrol allowed for oils with Group III bases to be labelled as "synthetic". However, at least as far as the 0w-xx crowd shows, PAO still is a key component, in varying quantities, regardless of that fact. Castrol's own 0w-40 still has a good slug of PAO in it, which they would be sourcing from somebody like XOM or CP, and if they could get away with making it all Group III, I'm sure they would.
All three of Mobil's 0w-20's have significant amounts of PAO in them, with the EP and AP products being well into majority territory (according to the MSDS anyways). So these oils are far from "cheap" to formulate and likely, are as close to the "old" Mobil formulations, in terms of the amount of PAO in them, as possible.