Originally Posted by babymog

The 190D 2.5turbo was never made for North America in a 5-speed, not sure it was anywhere. It was only built MY 1987.

At the time, Mercedes felt (as did Audi) that the turbo engines had so much turbo lag that it would not be civilized mated to a manual transmission so they only built them with automatics.

The automatic with its torque converter in the '87 190D 2.5turbo would easily spin the tires in the wet (annoyingly easily at times), and really could have used LSD. A tame ALDA setting will help but the sub-2000rpm boost rush tends to make it a bit squirrelly in the wet. With a clutch, I would think that it would reward the technique of rolling on the power as you release the clutch to keep the engine out of the full-boost range until fully engaged. With the 2.65:1 it should be fine, it is a torquey little beast. Even though a turbo engine, with a rich ALDA it is also a 2.5L diesel in a car that at 2800lbs weighs less than a modern Jetta.

Originally Posted by t walgamuth

That jump in ratios does not seem out of line to me. Getting the car moving with a torque converter is much easier than with the clutch.

The 346 was used in the 123 300D na. It'll make a sweet ratio for taking off with the stick. I'd prolly go with the 307 though.