I think ticketing for 5 over would open up the floodgates to a debatably valid reason/excuse: a speedometer only reports accurate numbers when tuned to the whee

I think ticketing for 5 over would open up the floodgates to a debatably valid reason/excuse: a speedometer only reports accurate numbers when tuned to the wheel configuration. It's common enough for tire sizes to be changed on a vehicle, especially in regions where larger summer tires are swapped out for smaller winter tires, without the speedometer readings being adjusted for the new tire size. It could be argued that the vehicle owner is responsible for ensuring this adjustment is made every time tires are changed, but with no real way for the average consumer to verify or measure the difference, the fact is we depend on the business providing the service to do it for us.