My 83 300D has 324,000 miles. I paid $700 for it and am the 2nd owner, put about 18,000 miles on it since I had it. I use normal 10W30 oil and it seems to be fine. I change my oil no more than every 4000 miles.

It does not burn any oil and I expect to drive it for another 100,000+ miles. It is in excellent shape. Shall I start using Synthetic Oil or other high end oil as per this forum? Your comments is appreciated.

83 300D, 87 300SDL ( 320,xxx miles )

Another important thing to remember is ZDDP. Our flat tappet setup requires an oil containing a high zinc content in order to protect the top end of the engine. Using a modern oil with a low amount (or complete absence) of ZDDP means death for your valvetrain. This fact alone is a strong reason to stick with diesel-rated oils like Rotella and Delvac.

I have been using AMSOIL Synthetic Heavy Duty Diesel & Marine Motor Oil (AME) 15W-40 as my oil over the past 200K miles (I have 373K miles). It is a 91 300D. I recently had my head gasket replaced and replaced the valve guides and basically did a light top end rebuild (because we had the head off anyway). Condition of everything was pretty good and I think we would have made it to 500K with no work.

Its Shell Rotella T 15w40 for both my 123 and 126 all year round.
I have tried the cheaper brands and I have noticed a significant decrease in fuel consumption with the Rotella T and also it seems to burn less oil.

Big Dan
Vancouver Canada

I'm using Delvac 1300 15W40 right now.

Any of you guys try Castrol Tection 15w40?

Om603/om617
 

Shell Rotella 15W40 year round

I use Synthetic for two reasons one it aids in cold start ups provide quicker luberication of the engine. 2 as forced induction showed it keeps a motor clean

Hi, I have just bought a 1988 190d with 437k on the clock, I'm running 15w-40 right now but have 4 jugs of 5W40 Duron (Petro Canada brand) Synthetic oil. Is changing to synthetic a good or bad choice for me? Only some people say on the higher mileage cars there may be small cracks plugged with oil/carbon etc that can be stripped out with the more thorough cleaning job that synthetic does, any thoughts?

Also, a side note, a quick check on autotrader.ca shows that there are no 190d's for sale in Canada (on that site anyway), how rare a car is it in Canada, were not many sold or do people just hang on to them?