On Thu, 1 Jun 1995, Dave Kautz wrote:
>  Hi Gerry, o lucky GNATT participant,
Yeah!

>  Saw your post on regarding speedometer error and the first thing I thought 
>  of was tire size. What are you using? Speedometers are usually a little
>  optimistic but not to the degree you noted. However, using 185/75-14
>  tires <which are much more available then the 185-14C that the speedo 
>  gearing is expecting> may account for most of your observed error. The 185/75
>  -14 tires are just over 6% smaller in diameter and therefore rotate more per
>  distance travelled, etc....you already know all this stuff.

I posted a little after my first note that I have measured my odometer 
error (yes I'm running 185/75-14 tires) as 2%.  Are they really 6% 
smaller?  That's a lot.  Even if they were, though, that would bring a 
65mph measure down to 61.1, not 57.

My real question is whether I should replace the cable or tear apart  the 
speedometer.....

Thanks!
--
Gerry
Gerald Skerbitz <gsker@med.umn.edu> U of MN Med School Admin 6-5379