As I've been considering buying a Gtech SS, I'm just curious how the thing gets torque, 60', 1/4 miles, 0-60, etc. all just hanging from your windshield. I understand it has accelerometers and other gizmos, but how does it know how fast you're going? Or whether you've gone 60 feet? Or a quarter-mile?

Not that I need to know before purchasing one -- I understand they've been proven to be very accurate -- I'm mostly just curious. Anybody know?

 

It's all based on mathematical equations off from the accelerometor data.