PeachParts Mercedes-Benz Forum - View Single Post

tcane · #22 04-15-2002, 11:38 AM

Bo:

Thanks for the reply and info. I picked Chevron's Delo because its specs and reputation were very good. I want to switch to synthetic oil to reduce wear and lower temperatures, although the better diesel oils (like Delo) should also be good, just not as good.

I rebuilt the engine using cast iron alloy piston rings made by Deves and they do a far better job of sealing the combustion chamber gasses from the cranckcase when compared to the chrome plated rings M-B uses. The M-B rings use combustion gasses to force the ring against the cylinder wall and this design allows some combustion gas to enter the crankcase. The Deves rings do not use combustion gasses to seal the ring to the cylinder wall and far less combustion gas enters the crankcase. I can verify that far less combustion gas enters the crankcase because the oil has remained very clean and with the M-B rings the oil would look dirty almost immediatley after an oil change (on the diesel forum many other owners would agree with the dirty oil look right after an oil change).

My point being that I do not think soot will be a problem even though Mobile 1 Tri Synthetic has a CF rating. However, as you wrote, the only way to know is doing an oil analysis. Also, I was planning on changing the Mobile 1 oil at 5,000-6,000 miles based on my driving habits of 70-80% highway driving with distances exceeding the time needed for the oil to get hot enough to purge contaminates. Replacing the Mobile 1 at 5,000-6,000 miles and replacing the oil filter mid-way (at 2,500-3,000 miles) should minimize the potential problem of soot contamination. I will take an oil sample at about 3,000 miles for analysis no matter which synthetic oil I use to see what the results are to make sure that the engine is not being damaged.

Any comments/suggestions you have would be appreciated. I look forward to reading more of your insights about Mobile 1's machinations and news about other oils.

Tom