I just bought a 1991 300D 2.5 turbo and was wondering about the benefits of switching over to synthetic oil. First my car has 125K, is there too much gunk residue from standard oil to contaminate and compromise the benefits of switching to a synthetic oil. And if not, can I get some recommendations...I read about Mobil 1 and Amsoil being the best...viscosity for Atlanta, Georgia?

 

There's no such thing as too many miles to switch to synthetic unless you have a vehicle with a wet clutch (ie: motorcycle). The synthetic will still encapsulate contaminants and clean them out of your engine more efficiently and lubricate better than straight dino oil.

 

Hi guys,
I'm also thinking of switching to synthetic oil...is there an effect on the gaskets or rubber o rings ?? Will synthetic oil shrink the old gaskets and introduce leaks on the weak areas??...I appreciate the heads up.