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Old 05-27-1999, 12:01 PM
Posts: n/a
I'll offer my personal experience on oil.. I've used Mobil One in my 78 300CD since it had 10,000 miles on it.. it now has 285,000 on it, shows no sign of wear, runs perfect, and under the head cover is squeaky clean... no deposits or sludge. I've changed it every 3,000 miles or less and used everything from 5W20 to 15W50.. but prefer the lighter oils. The engine is so tight that when I occasionally used petroleum-based oils it was very sluggish until it warmed up. With the synthetic the starter spins it with gusto and I can start a cold engine down to below zero degrees at 6,000 feet altitude without a block heater... and it runs better the first few miles.. not so sluggish. Back in 1979 I wrote Mercedes and asked if Mobil 1 synthetic was an approved oil. They replied in the affirmative. Yes, it's more $$$, but for me I think it has been a good investment considering the $6,000 cost of a new engine and 17 years without a car payment. As for the wisdom of switching to synthetic on a high-mileage engine, there are a lot of opinions out there and I could not tell if they're substantiated or not. I would guess that if the engine is in good condition then there would be little harm in doing so. A lot of "wives tales" get propagated about oil as you know, but how much is sound wisdom is hard to determine.