Speedometer Error Fix?

[Rod Stewart]

I have noticed for quite a while now that my speedo reads about 5% high at most speeds compared to my GPS.
Can this be corrected or recalibrated??

Thanks,
Rod

 

[dhorne]

you will also find that most GPS are out 3 mph as a rule of thumb or used to be anyway

 

[glider]

Very few speedos are dead on, they usually are off by a number of MPH. Nothing much can be done without going crazy. Even tire pressure will effect the readings.

 

[fin_676]

speedo is allowed to show a little higher than actual speed by up to 10%
but not allowed to show lower than actual speed
even if you managed to get the speedo spot on for speed youd have to change the tyres frequently cos as the tyres wear the rolling radius of the wheel is reduced so although the wheel is turning at the same speed you go less distance so a speedo can never be 100% accurate
at an indicated 60 mph id expect real speed to be between 56 and 58 mph depending on current wear on the tyre

Brian