Diesels (in general, not just VW ones) have a narrower set of RPMs
where they are most efficient than gasoline powered engines. That's one
reason why the gears are so "low". They are really designed for a
narrow spectrum of RPMs...in trucks, they add more gears so as to allow
the vehicle to travel at higher speeds. VW didn't do that for the
Vanagon diesel. It really should be a six speed.

To broaden the RPM range, manufacturers can do a variety of things. The
simplest is to add a turbo charger. That helps, but a diesel really
works best if it is running at constant RPMs.

On Thursday, June 5, 2003, at 06:43  PM, Dennis Haynes wrote:

> All the NA Diesel Vanagons had a factory placed sticker on the engine
> that read "Not Suitable for AC Installation". If the Diesel had so much
> torque, then why do all VW Diesel vehicles have ridiculous low gears?
>