The M-B diesel history is somewhat puzzling:
The W123s diesels were bullet-proof.
Then, early six-cylinder W124s diesels were a complete disaster (the 4-cyl. were O.K. BUT not as reliable as the W123s, the 5-cyl 250D was the only who lived up to its reputation). Later production six-cylinder W124s were improved.
The W210s diesels improve on the earlier W124s, BUT they never were as reliable as the W123s.
Today, diesels are very reliable, indredibly FAST, and have a torque curve that will put gas V12s to shame.
The thing is that diesels make sense in Europe, where gasoline is EXTREMELY expensive, and cars are taxed according on how much they pollute the air. Today diesels are much cleaner than their equivalent gas engines, hence they pay lower taxes.
In the U.S., where gas is cheap, the advantage seems to dilute, and then you wonder is it really worth it to put up with diesel smell and having to pull aside 18-wheelers at gas stations to fill up for a few extra M.P.G.?
Just my 2 cents...
CL 500, 1998
S 500 L, 1998
E 320 T, 1995