Does your car track your speed?
Olivia Hensley
Updated on March 18, 2026
Event data recorders, sometimes referred to as a car's “black box”, are included in almost every new car. These recorders collect data on your driving behavior in order to record important information during an accident, like the speed the car was going and how fast the airbag was deployed.
Do GPS track your speed?
A modern Global Positioning Satellite (GPS) can record your speed. In fact, some smartphone apps can even track your car's location and speed. This can come in handy for parents who wish to monitor their minor drivers.Does my car have a built in tracker?
Check the undercarriage of the vehicle. Most magnetic or old GPS trackers are attached to the underside of the car. A tracker could be hidden under your car's trunk with the help of Velcro tape or bolted in place.How do cars know how fast they are going?
A car with a digital speedometer uses a speed sensor, which usually consists of a magnet surrounded by a wire coil, quite like the pickup on an electric guitar. The sensor is mounted directly next to a gear on the transmission, and as the gear spins, its teeth whiz by, interrupting the magnetic field on the sensor.How accurate are vehicle trackers for speed?
The accuracy of different units vary, but as a rule of thumb, assuming that there are at least 3 satellites visible in the sky, the GPS reading for speed will be accurate to about ±0.1mph.Difference between your car speedometer and GPS speed
Do speedometers show true speed?
A speedo must never show less than the actual speed, and must never show more than 110% of actual speed + 6.25mph. So if your true speed is 40mph, your speedo could legally be reading up to 50.25mph but never less than 40mph.Are car trackers wrong?
Your device can send location data with as little as 4 satellites, but you will jeopardize accuracy because of the lack of visible satellites. This low number of satellites can be normal from time to time depending on the tracker placement, location of your asset (under a bridge, trees, etc), and weather conditions.Do speedometers read high?
Car speedometers are not allowed to 'under-read' – they can't tell you you're going more slowly than you really are – but they are allowed to over-read by up to 10 per cent plus 6.25mph.How do cats know the speed limit?
Traffic-sign recognition (TSR) is a technology by which a vehicle is able to recognize the traffic signs put on the road e.g. "speed limit" or "children" or "turn ahead". This is part of the features collectively called ADAS.How far out are speedometers?
Speedometers are deliberately set to show about 10% higher than your actual speed. Please provide a citation or law requiring this to be the case on all cars, as I know of some which are set exactly. He's actually right, at least for the UK - might be different in other countries.Where would you find a tracker on your car?
A tracking device placed on the exterior of your vehicle needs to be weatherproof and compact.
- Using a flashlight, check both front and rear wheel wells. Use your hand to feel in areas that aren't easily visible. ...
- Look beneath the undercarriage. Use a mirror on an extendable pole to look far underneath your vehicle.