Which Oil?
 

I Just Bought 1990 300e 2.6 , Owner Has All Records The Oil Changes Used Everything Out There 10-30, 20-50, 10-40. What Is The Best Brand And Weight To Use For Texas.

You can browse this board and get every conceivable opinion about "the best" oil product for your vehicle, but the most experienced and respected members agree: Use the viscosities and grades referenced in your owner's manual.

If you want your engine to last to a ripe old age, the key lies not so much in the type of oil you choose (within the noted MB parameters), but in the frequency which you change that oil. "In short, change it hot and change it often!" is among the best advice I've ever gotten from this forum. All the rest is commentary...

Brand in not important. Read the owner's manual. Keep in mind the current API spec for spark ignition oil is "SL".

So all you have to do is pick an API SL oil in a viscosity range for your anticipated temperature conditions, and change it according to the owner's manual recommendation, or more frequently, if you prefer.

Duke

In addition you could look at this:
http://www.whnet.com/4x4/oil.html