Re: Speedometer/Computer Speed Discrepancy

["Chris Warren" <tofer@foxinternet.net>]

Atleast the speedo is off in the RIGHT direction, when it comes to the
highway enforcement.  
:-)
TOFER
tofer@foxinternet.net
'97 Jetta GT Black
Euroswitch & rear fog light

- ----------
> From: S. Joseph Mann <joem@pswtech.com>
> To: jettaglx@igtc.com
> Subject: Re: Spedometer/Computer Speed Discrepancy
> Date: Monday, January 19, 1998 2:53 PM
> 
> Khan,
> 
> I recently took a 200 mile trip to Dallas from Austin.  Over the course
of the
> trip, using the chronograph on my watch, my Newton and mile markers. I
> consistently came up with, on average, a 3 mph discrepancy at various
speeds.
> I'm certain that the "speedometer" is consistently fast and incorrect.
> 
> Joe
> 
> 
> Khan M. Klatt wrote:
> 
> > OK, check this out.
> >
> > My friend drives a Corrado VR6, and he and I (driving my Jetta GLX)
both
> > get on the freeway and peg our cars at 60mph w/ cruise control.
> >
> > We both checked our computers, and reset the computer's "Average mph"
> > guage, and both cars showed 57mph.
> >
> > I have stock wheels and tires on my car, and he bought VW wheels to
replace
> > his BBS wheels, but is using the same stock tires (or the same type of
> > tires as stock).
> >
> > It seems this speed discrepancy exists at all speeds-- approximately
3mph
> > difference between speedometer and computer.
> >
> > So, is there anyone out there that has facts or figures that would
indicate
> > which one is accurate and which one is not, and for what reason?
> >
> > I would tend to think the computer is accurate, but I want some hard
facts.
> > Any mechanics or engineers out there that know why this discrepancy
exists?
> > How about having it fixed?
> >
> > If the computer is wrong, does that affect the miles per gallon and
time of
> > trip calculations, etc.?
> >
> > Has anyone tested the accuracy of the temperature guage?
> >
> > -Khan
> 
>