Here is What he says:
The esters in Mobil 1 are "no more".. One of the evolutionary changes was the elimination of the ester portion of the formulation (needed for additive solubility, natural detergency, seal swell). Thus Mobil 1 is essentially all PAO now, enabled through the magic of chemistry; even superior performance without the negative aspects of the ester.
George Morrison, STLE CLS
I realize my statement (Esers gone!) is a bit of a shocker. But it is true.. Mobil's latest formulation goal was to eliminate ester's from the program. Ester additization has been around since day 2 (day one found the additives at the bottom of the container: additive fallout!) and have been a cornerstone of Group IV PAO synthetic oil formulation. But, if one looks at the current MSDS for Mobil 1, you will note the absence of ester.. It took years of work to achieve a formulation that significantly outperformed the PAO/Ester blend but, Mobil did it..
This is what Sypersyn was all about; the ads about it being revolutionary, new, etc. were true..
Additive solubility, seal swell, detergency were all achieved..
George Morrison, STLE CLS
Regarding the supposed advantages of ester in Mobil 1: it was merely a balancing of chemistries to achieve an end. It has always been a goal to eliminate or minimize the ester 'blend'. As previously indicated, esters are *very* hygroscopic. The last thing we need in an oil formulation is a component drawing water into the fluid, which is what esters do.. Esters are very reactive. (i.e. the natural detergency, seal swell, additive hold). So the real chemical breakthrough was the ability to have a homogeneous chemistry that enabled all the positive aspects of ester without the drawbacks: which is exactly what has taken place. And performance-wise, which has always been the Mobil standard, no compromise: just the opposite, increased performance in every parameter.
Regarding Mobil tech support: they are not going to share formulation. This formulation is multi-patentable, super secret deal!.
However, it is not rocket science: the MSDS for old formulation Mobil 1 indicated >10% ester. New formulation Mobil 1: no ester component is mentioned....
This is what Mobil was all excited about! To be able to significantly surpass the PAO/Ester blend performance without the ester.
George Morrison, STLE CLS