Originally posted by loubapache
I would "continue the "tradition." "
The only issue might be viscosity. Being where you are and what MB approves, 0W-40 and 15W-50 are the only two you may want to use.
0W-40 is still hard to find. It is only available at MB and Porshe dealers and Mobile distributors where it costs an arm and a leg (around $5-8/qt).
15W-50 is easier to find (Wal-Mart).
Some people use 10W30 (I do in the winter here in Michigan) but in theory, it is not one of the MB approved oil.
I think that the "approval" is for a new car. On a car that has 150,000 miles on it I would not bother with what Mercedes approves. I think any Mobil 1 is going to be better than anything that Mercedes approved in 1989. The 0W-40 approval is more for meeting fuel mileage requirements than what is good for the car.
1991 Mazda Miata 174000
1991 Subaru 189,000 Winter beater
got rid of:
1984 VW Vanagon 195,000
1976 350SE Euro 185,000 KM
1973 280SE 4.5 (boy do I regret that)
1980 280SE European W126 4 speed manual (miss it)
1989 BMW 735iL 119000 (good riddance)