Why is there a 5 mph difference between my Sat nav and the speedometer in the car?
Newgran asked:
If I’m driving at 60mph according to the speedometer why does it say 55mph on the sat nav screen.
Which is the more accurate?
Contract Mobile phones
If I’m driving at 60mph according to the speedometer why does it say 55mph on the sat nav screen.
Which is the more accurate?
Contract Mobile phones
One of them is faulty
The sat nav is often slow to catch up but at a steady speed i would say it is the more accurate.
The analogue speedo can be affected by different things, eg if your tyres are underinflated, the speedo will show slower than your actual speed/
cars are always clocked higher to stop you speeding
Car speedometers are not 100% accurate unless they are calibrated. Your satnav will be giving you a reading that is very accurate if you are travelling at a constant speed.
Car speedos only have to be 10% accurate, the sat-nav will be the correct speed, or very close to it. Car speedos usually over-read slightly, so you don’t get nicked for speeding only 2-3mph over the limit.
Speedos in a car are calibrated at least 5% lower than real speed to account for tire size variation due to variability on tire size, car load (which reduce the radius of the tire), tire wear and tire pressure.