[JFP in PA]

Originally Posted by PaulE

I would bet your odometer is still very accurate, years ago automakers got in trouble for that as warranties would expire sooner and gas mileage would look higher. If you really want to find out if something can be done, try contacting North Hollywood Speedometer or Palo Alto Speedometer. If something can be done, I'm sure it won't be cheap!

Good luck with that; the Boxster uses one of the ABS/PSM wheel speed sensors to determine ground speed, and the instrument cluster gets that information from the DME. Considering Porsches penchant for incomprehensible logic in the DME software, you would need to reprogram the DME, which is anything but easy, even with a PIWIS. And the government gave automakers considerable leeway on instrument cluster accuracy a long time ago, which is why these cars have idiot lights that move instead of real instruments.