Got any reasonably lightly travelled highways in the area? Run at
steady speed past 10 of the numbered markers along the highway using a
stopwatch for timing. Poor man's VASCAR. GPS would work as well.

Cal proclaimed:
> got my numbers by my son following me in his wrangler, me in my GC. I know
> my speedo is about 1 mph off (in the GC) because of the radars that display
> speed on the side of the road used by our local police. We compared our
> speeds by cell phone. I know not the most accurate way to do this....
>
> cal
>
> "billy ray" > wrote in message
> ...
>
>>Generally Jeep speedometers get more accurate with larger tires.
>>
>>How did you get your numbers?
>>
>>
>>"Cal" > wrote in message
. com...
>>
>>>97 wrangler, just put 31's (tires) on it. Speedo says 64 when actually
>>>going about 70 now. Tire guy said may make 1-2 mile per hour difference,
>>>but this is lots more! Any adjustment, or just get used to it?
>>>
>>>thanks
>>>
>>>cal
>>>
>>>
>>
>>
>
>