Is the speedometer adjustable

I have an 89 xj40, currently the instrument cluster is out for resoldering. The speedometer has always read 5 mph slow. there is no mechanical cable so it must be electronic. Is there a screw I can use to set the proper speed on the back of the speedo to read correctly?

Not that I’m aware of, in some (all?) countries its mandatory for speedos to read high, just compensate.

I have been doing that just figured while the cluster is out I could make it right.

I went up a profile on both the XJR and the wifes Mazda 6 didn’t correct it but made the Mazdas 8klm high a bit more like 5

David, what size tires are you running and what size was original to the car?

original size as recommended.