Most manufacturers deliberately include an error on the speedo so they report 5km/h high (about 3mph). My two cars have 2km/h and 3km/h errors
You can look up the speedometer error for most cars, you can test your own using a stopwatch and a measured distance and maths, or a GPS that shows speed to one decimal place. I use GPS essentials
Most manufacturers deliberately include an error on the speedo so they report 5km/h high (about 3mph). My two cars have 2km/h and 3km/h errors
You can look up the speedometer error for most cars, you can test your own using a stopwatch and a measured distance and maths, or a GPS that shows speed to one decimal place. I use GPS essentials
GPS speed is very accurate.