hi
does anyone know of any where that does speedo calibrations
mine is out by about 10% maybe a bit more it got through the MOT but im fed up with not knowong exactly what speed im doin lol
its a mk1 punto 60s

What size of tyres have you got?

yes, they overread.
no theres nothing you can do about it.

if its a 60s it SHOULD have 155/70 r13" tyres on it
if it has 14" with 165/65 r14" tyres on it there will be little to no difference.

what size does it have currentlyu?

the speedo is not a serviceable item.it has a precision spring in the back.it is very rare for them to be faulty and they last the life of the car.the wheel or tyre size is the obvious cause,try swapping the wheels front to rear and see if it makes any difference.did you find the error through a gps device

if you have a rev counter use THAT to indicate true speed.
e.g 5th 3000rpm = true 60 I believe.
4th 2000 = true 30
etc etc

thats a 1.2 8v mk1 with its correct sized wheels, there nothing wrong with it, they are just designed to overread that bit.
a gps will show you just by how much