> This is a web site that analyses your speedometer accuracy.
Well, dang it ! First thing they want to know is a measurement ! I was
hoping it would just magically tell me what was wrong with my speedometer !
If you've got a calculator (like the one included with every copy of
Windoze) you don't need the web site. Divide the number of miles you
traveled by the number of seconds it took to travel it, then multiply that
by 3600 to get mph. Divide the result by the indicated speed to get
speedometer error, then multiply by 100 to get error in percent.
Note that many speedometers have different amounts of error at different
speeds. I've owned cars that were off by only 1 or 2 % at 50 mph, but 10%
Also, if you belong to AAA, they have periodically have speedometer test
sessions that are free to members. They'll put your car on a dyno and run
it at varying speed, then print out a chart showing your true speed at each