lumpydo

I have one of those speedometer app downloaded on my smartphone. Just out of curiosity I turned it on the other day when I had my cruise control set at 75 miles per hour. The readout on my phone showed me is only doing 71. I downloaded another app just to see if the first one was off and it was not. Is it possible with stock rims and tire sizes on my car for it to be that far off? Is there a way to calibrate it?

snagitseven

That is very typical. Auto manf. almost always program the speedometer to read 5% or so below actual. Different tires can also affect this due to the variances in overall circumference. You can adjust the computer mpg readout in the DIS using Vag-Com but not the speedometer or odometer.