88 300d Oil?

Is it OK to use a synthetic engine oil in my 1988 300d?

[Michael]

I run synthetic Mobil Delvac 1 in my '92 D, which is the same motor minus a cylinder...excellent oil for your engine.

[DieselHead]

Why not? I plan on putting Delvac 1 in my 1983 soon. Just be extra vigilant of oil spots and drips under the car.

Alex

[JimSmith]

robdog,

I have used nothing but synthetic oils, mostly Mobil 1 for the engines, since it became available on my Diesels and gas M-B's. I used RedLine engine oil in my 190E 2.3-16 for a while, but switched to Mobil 1 15W-50 when it became available.

I now use Mobil Delvac 1 in my Diesels, and my 1982 240D "loves" it. It starts better, has less blow by, and passed the CT state emissions test with a 0.1% opacity rating out of an allowable 20%. My 1998 E300D TurboDiesel has only been in my "fleet" for under 6 months, so I cannot detect much of a response to the change. It came with Mobil 1 0W-40 in it when I got it from the dealer.

I have yet to experience a change in oil leak rates when I switched a used car to synthetics, or any notable leakage in one of my cars I bought new and always ran with synthetic oil. The only potential for an increased potential leakage I can point to was the original Mobil 1 released for sale in the mid '70's. It was really more like water than oil in its viscosity, and I did develop a rear crank seal leak with that in the summers, although by the time the car (a 1975 240D) got to 40,000 miles, the leak stopped.

Newer synthetics are even less likely to leak as they come in the same viscosity ratings as "dino" oils. Go ahead and make the change, and feel good about it. Synthetics make for more reliable cold weather starts, less wear at start up, better cleanliness inside the engine. Good luck, Jim