Here's how car speedometers calculate how fast your vehicle is going. And here's why they may not always be accurate.

A new feature that's no longer available ...

A significant number of Android Auto users are seeing problems with the speedometer and traffic data on Google Maps.

Honestly officer, I was only going 50… Google Maps just lost an essential Android Auto feature again ...

Android Auto users are reporting that this recently rolled out feature has disappeared, and so has traffic lights and stop signs.

Android Auto users are reporting an issue where the Google Maps speedometer, available for mere months, is randomly vanishing ...

[Martyn] is restoring a 32-year-old Honda motorcycle, so when the ancient speedometer broke last year he thought it was prime time to start of a digital speedometer project. We’re loving the results ...

If you drive your hot rod, even once in a while, then you depend on all of your gauges to be reliable and accurate. Just a small percentage of miscalibration can result in engine damage or failure, ...

If you've ever modified a car with smaller or larger tires or, perhaps, a different final-drive gear, you've immediately screwed up your speedometer. This is, of course, annoying, but for modern cars ...