Dialing in Speedometer/Odometer

easy way is to go on mapquest and get the mileage between two local points nearby. Then drive it an see what
your odometer says. calculate the error example, if you read 10 percent more than mapquest says you need
a speedo gear with 10 percent more teeth, that would slow the cable down by that amount. the speedo gears
come in different colors, find the closest one based on the gear presently installed. Keep in mind that your
speedo is probably not very linear, different errors at different speeds, so split the difference or get a GPS.