First of all, let's nip this in the bud:
quote:
PAO's do not have very good solvency.
Solvency of what and relatively to what? PAO's have excellent solvency for dirt, combustion by-products and for their additive packages in automotive (and other) applications. PAO's have better solvency than Group's I,II and III.
I will agree with Terry to some extent, that new low emission, hot burn engines put motor oils to extreme solvency test. POE (polyester) based oils can and do excellent in these applications, due to their naturally good solvency (and more due to the ability to hold up under brutal oxidizing temps) but at a huge cost premium to PAO's. ($7.50+ qt vs under $5 qt). But in long term realistically, this cost premium, to pay for this solvency (over PAO's not petro oil), has not shown many benefits. In fact, most analysis data over the last 1.5 years doesn't show POE based oils as the magic bullet they are on paper. PAO's do quite nicely, thank you.
So again, buster, what we learned last year, still applies this year, and next. A motor oil needs to be good in ALL aspects...and solvency is another important aspect.