Speedometer Accuracy compared against GPS
I was reading through the MPG thread, it struck me that speedometer inaccuracies can account for mpg differences drivers are experiencing amongst all the other myriad of reasons.
Im currently driving Passat Estate Blue Motion 1.6 TDI
Long term average is 49mpg
Short term to work and back is 55mpg
Long slow drive being careful 67mpg over 100mile
However the speedometer reads 76mph when in fact i'm travelling at 70mph displayed on a GPS.
55 = 50
44 = 40
33 = 30
22 = 20
The Speedometer reads increasingly high through the speed range.
So, how accurate are the A3 Speedometers?
Andoid phones can be used to display speed over the ground.
Nice free app here