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 ."
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[ don"t worry the answer to hygroscopic is in the next sentence] . 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 [with the new supersyn no Ester Mobil 1] . And performance-wise, which has always been the Mobil standard, no compromise: just the opposite, increased performance in every parameter.
