From the bible....  90.30

"speedomteters having European calibration specifications were installed in
vehicles for model years 1984 through 1985.  These speedometers heads have a
basic tolerance of (+) 6.2 mph with an additional (+) 5% of the actual speed
driven."
Example from the bentley:
Actual speed            50 mph
+ Basic Tolerance               6.2
+ 5% of Actual          2.5

Maximum indicated speed: 58.7 mph.

This assumes OEM tires and normal tire wear.

After December 1984 production the tolerance is just (+) 3 mph.

The tolerance for all odometers is (-) 1% to (+) 3.75%.

Mark Kreuzer
85 Westy

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Michael Elliott
Sent: Sunday, June 19, 2005 8:44 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Speedometer -- the straight scoop

I know this is a done-to-death subject, but I searched the archives and
didn't turn up what I was looking for:

The facts, as I know them:

According to yesterday's "speedometer check" signs posted by the side of
Interstate 8, my odometer is a smidge optimistic: when I had traveled 4
miles, the odometer read 4.1 miles. Close enough for me. 2.5% error.

The speedometer reads pretty low. According to the "Your Speed Is"
automated trailers with giant speed displays parked on the streets AND
according to my GPS, the speedometer is WAY optimistic: when I'm going 65mph
the speedometer thinks I'm going 75. This is a fixed percentage:
as I go slower, the mph error is smaller but the percentage error is the
same. About 8 - 9%.

So the odo is acceptably accurate, the speedo is not so accurate.
Anything a fellow can do other than just mentally correct the speedo
reading?

--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana") Carlsbad, CA KG6RCR