Oil question - what weight is best?
 

Hi all. I'm tried a search but didn't get any relevant posts...which oil should I put in my '83 380 SEL? I believe there is 10W-40 in there now but I want to change it before the first frost. Any suggestions would be appreciated. Also which brand do you suggest? Thanks again.

Have you looked in your owner's manual? It will list approved viscosities for the ambient temperature range you expect during the time the oil is in the car.

Brand is irrelevant! Select the most current American Petroleum Institute specification for spark ignition engines, which is "SL". The API spec is listed on the label.

It is unlikely that you will find anything on store shelves that is other than "SL" or "CI-4" for diesel engines.

Duke