Speedo Accuracy

[d0gz_bollox]

Is it possible for a speedo to read incorrectly by any means other then tyre/wheel sizes. i.e. could there be a mechanical fault or adjustment that could cause a speedo to read 10/20 mph out?

[CP]

They used to come out of the factory inaccurate by quite some margin. Helped make cars a little bit faster.

[ade]

what are you experiencing? If the speedo isnt reading accurately, check the connectors at the back of the dash. Can you see anythong in the dash fouling the needle?