The one benefit I see from synthetic oils that petroleum based oils cannot offer is the wider spread of viscosity available in a single product. It allows the oil to protect under a wider variety of conditions. I run Mobil 1 5w50 in my C280, which is a synthetic. I like the fact that it flows to the top end of the motor faster on a cold start AND provides me with superior high temperature protection at the same time. Now for the E320, the manufacturer recommends the Mobil 1 0w40, so that's just what I use in it. But again, that is a larger viscosity spread than you'd ever see on a "dino" oil.

I only put 5-7,000 miles a year on the C280 so this becomes a great solution for changing the oil once a year and not having to worry if I have the right "weight" in the motor. Its always appropriate for the climate.

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Jonathan

2011 Mazda2
2000 E320 4Matic Wagon
1994 C280 (retired)