you are all under the assumption that every car on the road has a 100% accurate speedometer also. people put wrong tires/tire wear/wear on mechanical parts can all cause your speedometer to be off by different margins. Just more fuel to the fire.
you are all under the assumption that every car on the road has a 100% accurate speedometer also. people put wrong tires/tire wear/wear on mechanical parts can all cause your speedometer to be off by different margins. Just more fuel to the fire.