What does the engine tachometer mean?

[SadieRose]

According to the data, the engine tachometer is an instrument used to measure the rotational speed of the engine. It is generally installed in the instrument panel, symmetrically placed together with the speedometer and odometer. The function of the engine tachometer is to detect the working state of the engine and promptly identify any vehicle faults. The method to check the engine tachometer is as follows: The engine speed can be determined by viewing the engine tachometer on the car's dashboard. Generally, the displayed number multiplied by 1000 gives the current engine speed. The engine speed relates to the number of work cycles per unit time or the effective power output of the engine, meaning the engine's effective power varies with different speeds. Introduction to engine speed: The engine speed affects the number of work cycles per unit time or the effective power output of the engine. Therefore, when specifying the effective power of the engine, the corresponding speed must also be indicated, which necessitates the use of an engine tachometer to monitor the engine's speed. Working principle of the tachometer: It receives the pulse signal generated when the primary current in the ignition coil is interrupted and converts this signal into a displayable speed value. The faster the engine speed, the more pulses the ignition coil generates, and the higher the speed value displayed on the tachometer. Engine speed, gear, and vehicle speed are interrelated. All car engines have a speed at which they output maximum torque. When the transmission is in a certain gear, and the engine speed reaches the point of maximum torque output, the vehicle speed will inevitably reach the maximum speed that the gear can handle, at which point a gear shift is required. Precautions for the tachometer: During a cold start, if the engine idle speed is below 800r/min or above 1200r/min, attention is required as this indicates poor engine performance. While driving, try to avoid operating the engine below 2000r/min, as low speeds can lead to insufficient engine power, excessive load on the engine at low speeds, potential engine damage, and increased carbon buildup. When the engine operates above 4000r/min, the combustion time shortens, leading to incomplete fuel combustion and a significant increase in fuel consumption. If driving normally in fifth gear, the vehicle speed would typically reach 150km/h, which is already a relatively dangerous speed. Operating the engine between 2200~3500r/min is the most economical and optimal for engine performance. It is advisable to maintain the engine speed within this range during regular use.