velocímetro

A velocímetro is a Portuguese and Spanish word that translates to "speedometer" in English. It is an instrument used to measure and display the instantaneous speed of a vehicle. Modern velocímetros are typically digital, showing the speed as a numerical value, while older models are analog, using a needle to indicate the speed on a dial.

The primary function of a velocímetro is to inform the driver of their current speed, which is crucial for obeying speed limits, maintaining safe driving practices, and optimizing fuel efficiency. Many velocímetros are integrated into the vehicle's dashboard, often alongside other essential gauges like the odómetro (odometer) which tracks total distance traveled, and the tacómetro (tachometer) which measures engine revolutions per minute.

The technology behind a velocímetro has evolved significantly over time. Early mechanical velocímetros relied on a rotating cable connected to the vehicle's transmission, which drove a magnetic or eddy-current mechanism to move the indicator needle. Contemporary digital velocímetros often use electronic sensors, such as wheel speed sensors or transmission output shaft sensors, to calculate and display speed. This electronic data can also be used by other vehicle systems, including cruise control and anti-lock braking systems.