As a general rule on the 123 chassis cars, the newer the better. You have a more reliable glow plug system, climate control, etc...

Don't buy a 240 unless its a manual. The automatics are dogs. Not that the manual is much better... You've got around 67hp. However, they are extremely easy to work on and are very reliable.

A 300D turbo has much more power and is overall a great car too. They are almost all automatics but that isn't a problem. They will smoke a 240 in acceleration.

I don't think you can really go wrong with either. Having said that I would definitely lean towards the '82 or '83. I think the most important thing is to buy the one that is in the best condition. Parts aren't cheap.

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)