Tachometer Odometer Speedometer | Instrument Cluster Tools Explained The tachometer , Odometer , and Speedometer are the main tools present in the instrument cluster panel in the vehicle dashboard. The tachometer shows us the RPM of the engine. The odometer is a reading show unit that says how much distance the vehicle has traveled till now. And Speedometer indicates the speed of the running vehicle. These are the main instrument cluster devices. Apart From this there any many others like, fuel gauge , engine temperature, and all signal lights, and indications that are present in the dashboard of the vehicle. In this article, I have covered everything detailed about essential devices like tachometer odometer, and speedometers. See the below image to get an idea of what an instrumental cluster panel looks like. What is Tachometer? A Tachometer is also known as an RPM (Rotation Per Minute) gauge. It is a device that shows the speed of the rotating engine shaft. They are two t