vauxhall corsa 1.4lswhy is my speedo reading 20 mph when i am doing 30mph?

Has it got aftermarket alloys on it? That will affect the speedo reading if they are not the original size.

Les
February 2009

either you actual speedo is broke or the speedometer cable is broke take it back to where you bought if you got it from a dealer if priavate and you asked at the time if theres anything wrong with it and they said no they should fix it if not then you need to get it fix as its illegal cuz you'll end up speeding

Andrew J
July 2005