On Thu, 19 Sep 2002, Dennis Haynes wrote:

> Don't forget to factor in the built in speedo error of 6% + 3 mph. Or
> was it 6mph + 3%. I forgot.

Depends on the year.  Some time in the 80s the U.S. DOT eliminated that
requirement -- after that the only rule was that speedometers had to read
higher than the actual speed.  This probably explains why my Honda's
speedometer is off by close to 10% at 80 mph.

A hand-held GPS works pretty well for checking your speedometer
calibration. It has some lag, so you need a straight stretch of road where
you can hold one speed for a while to let the reading settle.

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
 / _` | | | | | |  +-----------------------------------------------------
| (_| | |_| | | | @ cyberspace.org
 \__, |\__,_|_|_| "To accept selfishness as an all-purpose excuse for
 |___/             mistreating others is to reject the whole idea of
                   right and wrong." -- Richard Stallman