There are two 4 speed transmissions for USA market diesel Vanagons.

DM has 5.43:1 ring/pinion ratio.  55 MPH = 3296 RPM, 60 MPH = 3596 RPM
DZ has 5.86:1 ring/pinion ratio.  55 MPH = 3557 RPM, 60 MPH = 3881 RPM
This is with the stock 185R14 tires.

I prefer to cruise at 3000-3300 RPM, so 55 would be right in my comfort zone
with the DM transmission.  The red lines on your speedometer are approx 4100
RPM for their respective gears.  It is possible to install a VW diesel tach
in the dash cluster, but you need to piece it together from combinations of
parts from both gas and diesel models.

Mike Snow

> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
> Of Mary Beth and Chris Geiser
> Sent: Tuesday, May 08, 2001 2:29 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: RPM's - diesels
>
>
> Along this thread, how fast are people driving their diesels?  I've got a
> '82 w/4spd 7 passenger.... assuming a tailwind, I never have taken it over
> 60MPH... is this about what others are doing, or is this too fast??  I
> understand there are differences with tires / inflation /
> speedometers, but
> in general terms....
>         Has anyone installed a diesel tach successfully?  How
> difficult is this?
>
> Thanks,
> Chris