Quote Originally Posted by V8Ian View Post
Half the power probably explains its superiority.
Not only that. The series diesel engine was quite happy to pull strongly from a little above idle (maximum torque is at 1750, and its not a sharp peak) to 4,000rpm meaning that given the four fairly closely spaced gears and the transfer case that puts almost all low range gears below high range gears, you always have a "right" gear for any sandhill, and approaching the hill close to maximum revs, ease off as you go up, without having to change gears or spin the wheels in an effort to keep going without stalling - both of which are fatal on a sandhill.

The petrol Series 2 was quite good, but the diesel was a lot better because of the wider range of torque. For a mid fifties design, that engine was very high revving for a diesel, without losing the virtue of low end torque that was characteristic of diesels of that era. I think it was deliberately designed to make best use of the same gearing as the petrol engine, which only had a slightly higher maximum rpm (4250) but a much higher maximum torque speed (2500).