wanting to buy Mobil Delvac 1 oil for next oil change.
What weight is best for my W123 1983 300D: 5W-40 or 15W-40?

Unless Columbus is seriously colder than Evansville, IN, I'd stick with 15W40. If you routinely get -20 F, the 5W40 will be fine for winter.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter,
Ill try the 15w-40.
Rarely do we see sub zero temos here.

The truckers use 15W40 universal grade oils like Delvac from anchorage to Mexico City. It works.

Good luck,

If you actually needed 5W40 synthetic motor oil, I doubt you would get the car started.

Delvac 1 only comes as a 5W-40, FYI.

__________________
"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