[Luke]

Several people have told me that the speedo is optimistic - reading 4-5 mph higher than the actual speed at ~60mph. I'll get a GPS on it before the week is out.

 

[Luke]

GPS on the way to work this morning. The speedometer is pretty much dead on - I did several tests at both 35 and 50mph and it was either on or off by less than 1/2 mph (which means it's on). Since it's digital/optical, yours should be correct also, unless you change to a taller or shorter tire.