Need help with comfortable towing weight and length.

Proteus wrote:

snip...

Its the same basic engine design used in Europe for years, in commercial light trucks and Sprinter vans (same with the 7spd trans). My friend has an older ML320 with 350k miles+ on original motor, so I expect this to last 10-15 years easy. MB diesels have a rep for being bulletproof in general.

I guess the question is, why haven't domestic car makers caught up?

Jeep is putting a similar 3L TDI in the new Grand Cherokee (sourced from Fiat). Both can get 30mpg+ on the highway (I'm getting 28 now in my break-in period). I'm sure it drops in half with a heavy trailer though...

Design margin and over all engineering are what I've always thought it was...

My 1970 2 seater's 2.4L in-line six & 4 speed manual got +30MPG and
occasionally 32MPG, but ate gas when 'on it'...down to 13-16 MPG going
+130MPH...of course it weighs in around 2,400 with me in it... :)

That with a side draft SU/Hitachi that I bored out, polished and racing
needles in over sized jets. Taper was extremely aggressive and had
STP in the dash pots.

OBTW, a hogged out and stroked 3.1L is built and ready, but now
noodling forced feeding it...yeah, blew up that 4 speed tranny power
shifting to 3rd at around 100 MPH