Warden,

My Father-in-law has a 1980 240D with a manual transmission, about 185,000 miles and the original clutch, and he routinely tows a small trailer (4'x8'x3') with a lawn tractor or load of wood about 145 miles nearly every weekend from June through October. He has done this for several years now with no apparent ill effects on the car. A 300D should be able to handle it no problem. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)