Looks like the discussion is passing from 0W-20 performance to whether Mobil 1 SuperSyn is a masterpiece or a piece of sh.t. A good time to add few words.
Most probably SS does not contain esters at all or their percentage was reduced till 1-2 %. Everything indicates that now the base stock is
PAO and, depending on oil weight, this or that percentage of alkylated aromatics (probably Dialkylbenzene) and HC. Suppose 0W-20 and 0w30 is made of PAO + AA, but 5w30, 10w30 and 15W-50 - PAO + HC. Dialkylbenzene provides excellent pumping and pour point even in arctic conditions.
There is no doubt in Mobil ability to produce the best oil, but in our days who takes in consideration the need of a dozen thousand of such car enthusiasts like this site participants if millions in N.America and Europe don't know what they have in their crank-case or don't take care of what their mecanics put there except oil brand, its SAE viscosity and declared nature. Are we so naive ? Like any other manufacturer Mobil is driven by competition and therefore needs to reduce cost. If, 3 years ago in Europe all 5W-40 oils (except Shell Helix Ultra and Castrol) were really 100 % synthetic and contained 85-90 % of PAO in their base stocks, now nearly all of them are called "synthetic technology" oils. OEMs do not take care too of what will happen with cars after 3 years warranty period + 2 years and the approach is similar to condoms' recommendations: don't drive your car so long, buy a new one.
FYI:
European Mobil 1 started to lose quickly the market share with their SS. Many car dealers, at least in Eastern Europe, refuse to buy SS for their services and wipe off shelves with old stuff. Could be that SS of first shipments was out of specs for some reasons, but could be already a trend.
Regarding so lovely and often discussed here GC. Unfortunately we may only guess what is really supplied to the USA and Canada and whether and at what degree this stuff is equal to European cousin.
Castrol Formula SLX 0W-30, never very popular and well sold in Europe unlike Mobil 1 OW-40 Tri-Syn, was launched by Burmah Oil in 1995 and it was really esters based till 1999 or 2000. Then, as it became usual, Castrol changed its formulation. I could get confirmation from Castrol people that it is not the esters based oil now, but no details how considerable were these changes.
Over a.m. 0W-30, there are at least 5 others:
- Formula SLX Turbo Diesel (European market)
- Formula SLX Zero-W (Japan market)
- Syntec (apparently North American market)
- SLX GM (GM stuff)
All BMW Longlife-01 (except SLX GM) and ACEA A3/B3
- SLX 01FE (BMW stuff)
BMW Longlife-01FE and ACEA A1/B1
Castrol 0W-40 (Super Racing or Formula RS Power and Protection) is nearly the same Formula SLX 0w30 with more VM. HT/HS is slightly higher then with 0W-30, Mobil 1 0W-40 and Motul 8100 0W-40, but shear stability or shear stability index of all is of the same order (+/-0.4 %) and seems depends more from a lot, though the temporary viscosity loss of each may differ more considerably.