Up until the end of 1985 the sds had the 617 5 cylinder engines. The 1986 and 1987 sd and sdls had the 603 six cylinder engines with the aluminium heads.

Unless one can find a really good example of them now. It may be wise to pass it by. The overall accumulated milage on them is usually questionable. A previous poster stated if the interior does not look good he walks. I agree with that point of view. Usually it takes a lot of miles before the interior deteriorates seriously.

You have to judge the mercedes diesels of this period individually. Unless there is unequivical proof the odometer reading is correct. The resale of them when fairly new alone resulted in many more dollars if the odometer was adjusted. So I believe they were adjusted as were many other brands at that time.

Remember most people purchased and paid a premium for diesel cars to accumulate above average overall miles compared to gas cars. To further compound the issue the odometers were a mechanically weak design. So as mentioned each car has to be judged with this thought in the equation.

I might have two diesels with correct indicated miles. I would never bet on it though. Two others have far more than indicated in my opinion.

All four still have excellent interiors. One of the suspected high milage ones had just about the whole car replaced at the dealership including the engine and interior. Owned by the state of Wisconsin at the time.

I guess money was no object for a government department.Consider it an excellent example of the public taxpayers money at work. They poured far more money into that car than it could be worth.

Everywhere I looked had been replaced. A european mechanic that had worked on mercedes for twenty years told me before I brought it. You should buy it for some strange reason it is still like new. He had used the the car for three weeks.