Originally Posted by willrev

I will only use shell rotella 15W-40 from now on in North Carolina Climate. CAstrol 20W-50 is too heavy for winter here and car does not run at proper temp to give any heat in cabin.

Tried Mobil One heavy duty diesel rated oil and I had more oil consumption than with Rotella.

The Mercedes dealer mechanic here highly reccomends Rotella unless I want to pay high dollar for synthetic and he personally told me not to do so since I still had to change my oil every 2500-3000miles with synth.