Join Date: Nov 2008
Location: Macedonia, The Former Yug
Speedometer shows speed higher than actual
Hello, it's me again with a question/problem:
I have an Alfa 145 1.4 boxer and currently the dimensions of my wheels and tires are 195/50/15. That's about 1.5% larger in diameter than the factory 175/65/14 but as it stands, my speedo is telling me I'm driving about 18-20 km/h more than the actual speed (measured by GPS, Ulysse Speedometer).
I think that the speedo isn't a classic cable connected speedo, but works with the sensor attached to the gearbox of the car, which many people say it is far more accurate than most cable driven speedos.
What is the cause of all this? Can the sensor be faulty? Can the speedo be faulty? Are the wheels and tires too much off factory spec?