I run Mobil 1 15W50 in my 300TE and 500E gas cars; the head was just off the TE (165k mi. on the original valve guides) and the inside of the motor was spotless.

I run Mobil Delvac 1 in my 300D. I've only owned it for 3 days, so I can't back up my preference with any facts other than I know Mobil 1/Mobil Delvac 1 to be high grade oil.

__________________
"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo