Drive slower, and the speedometer decreases. If you are asking how to (illegally) decrease the odometer's kilometer reading, then shame on you.
NOT! It is illegal to tamper with an odometer.
I would venture to say that all new cars have digital Speedometers. The cars computer knows all. It is where everything that the car does is processed and recorded. The days of the old speedometer cable and odometer cable are long gone.
road speed
Older cars have a cable, which is turned by a gear at the rear of the transmission, and this operates a mechanical speedometer. Modern cars have an electronic sensor in the gearbox which is linked by wire to an electronic speedometer.
A speedometer is a tool used to record a cars speed.
There is no speedometer cable to change. Subaru, like all modern cars, has an electronic speedometer. --Ken
How fast the vehicle is traveling.
To some extent, it can be used as a speedometer. However, it is nowhere near as accurate as your cars speedometer. There will also be a greater delay in the changes in speed than with a normal speedometer.
An instrument cluster is what displays basic information in your car. Information like the speedometer, fuel level, care temperatures... etc. Cars nowadays are mostly made with a digital instrument cluster.
A cars speedometer measures speed. A speedometer is a gauge that displays the speed of a vehicle so the driver will know how fast the vehicle is moving.
The speed of most cars today is limited by the computer, no matter what the speedometer says. My car's speedometer lists 140, but it actuality 120 is the top speed as the limiter kicks in and controls the speed by way of a fuel shut off.
Speedometer calibration differs depending on the vehicle and age. Some cars are calibrated by a technician with a computer program. Others require a gear change to drive the speedometer at a different ratio.