The long answer is that the automaker calibrated the car's speedometer to work with a very specific tire and wheel size. Installing a tire and wheel with a different diameter throws off all those ...
Although not necessarily 100% accurate, GPS-calculated speed will usually be more accurate that the vehicle speedometer. Professional speed testing equipment also uses GPS to provide highly accurate ...
Which is more accurate, the speed shown on a speedometer or a sat nav? On the occasions I use my smartphone as a sat nav, I get a readout of the speed of the car on the screen. It always shows a ...
This would be an issue with the car's speedometer where the needle would not accurately display the car's speed. Instead, it would be going up and down the speedometer without rhyme or reason.