I tried going to the web site you appended ... but I just could not wait for the graphic to fill the screen with my slowwwwww dial up connection. So, I cannot comment specifically on the "new" Mobil One oils. If the new oils are blends, I'd say stick with synthetics for the minor marginal cost. If the new oils are full base synthetics, they are probably ok -- but I think pushing beyond 7-10k miles starts building up contaminated oil under normal filtration.

I'd like to add my "two cents" worth on synthetics overall ...

For the most part … I think there is some marketing hype about crude base stock oils (dino juice) versus synthetic oils. For most of us who are not going to race our cars … or drive them at extreme temperatures under heavy duty conditions … or push the replacement cycles beyond 10k miles … its ok to use relatively cheap oils with low replacement cycles, i.e., 3k miles. However, there are reasons to use synthetics that became convincing to me about 10 years ago … I’ve been using Mobil 1, AMSOIL and Syntec over the last 10 years in different applications. Mobil 1 has been going into the three MB’s that I’ve owned – ’96 E320 (still have it), ’98 ML320 (sold) and a ’96 E36 AMG engine that I shoe-horned into a 1985 190E 16V (sold). While I don’t push oil replacement cycles beyond 7-8k, I just cannot force myself to dump oil at 3k intervals – it’s a pain and its just more waste and stress on the environment. Here are some of the reasons I go synthetic ….

Dino juice oils tend to break down at the higher operating temperatures of many modern engines, e.g., the new MB V-6.. The breakdown products can leave engine components coated with varnish deposits and sludge. Also, the oil that has been affected by breakdown increases in viscosity and is difficult to pump through the engine. Mercedes had to extend the warranty of older ML320’s because they meant the FSS to work with synthetics not dino juice – now they make it clear they want you to use synthetic oils to increase the replacement intervals.

Synthetics do not contain wax which make the dino oils more difficult to push during start up … particularly when its cold. Also, the long chain polymers used in synthetics remain relatively stable over long scope oils like a 0W40, 15W50, 10W40 or even a 5W50. Dino oils simply cannot provide long scope coverage like a “designer” molecule. A 10W40 dino oil is flacky and is not a good 10W nor a good 40W oil.

Synthetics work under lower friction and thereby produce less inherent heat while at the same time providing better heat transfer. Oils lubricate and cool at the same time, and synthetics seem to do a better marginal job of both. Part of the science behind the lower friction is the size conformity of synthetic polymer molecules.