tachometer is used to measure

• 2022-04-20

The engine speed is displayed to reflect whether the engine is working normally.Speed is a barometer of the working state of the engine. At idle speed and neutral gear, the engine speed shall be stable and within a reasonable range; When you press the accelerator pedal in neutral, the speed should change smoothly with the smooth lifting of the pedal. After the accelerator pedal is stable, the pointer of the tachometer shall remain at a certain speed scale. If the idle speed of the engine is high or low, the speed is unstable and the tachometer shakes, it indicates that the engine is faulty.

As a reference when shifting the manual transmission, select the appropriate timing to make the engine always work within the most economical working range. The torque of the engine has a maximum value only within a certain range. Beyond this range, the torque will be greatly reduced, the engine power is insufficient, and the car will not be able to accelerate, or even stall and stall. Therefore, it is most reasonable for the transmission to shift within the maximum torque range of the engine. And we only need to look at the tachometer to know this range. Some people say that the old driver can hear the sound of the engine by experience. I don't think it's accurate. At present, the car is very quiet, and the sound of the engine can hardly be heard in the driver's ear.

At present, most cars are basically adjusted to shift up and down at 2000 rpm. If the speed is lower than 1200 rpm, it is necessary to downshift. The speed correspondence is almost the same: the second speed of 2000 rpm can be increased to the third speed, the third speed of 42 can be increased to the fourth speed, and the fourth speed of 60 can be increased to the fifth speed. At present, some manual transmission models are also very intelligent. They can prompt to shift gears according to engine speed, vehicle speed and other signals, which is really good news for novices.

Judge the fault of the vehicle according to the engine speed. The speed reflects the working state of the engine. If the speed is unstable, high and low, it must be an engine fault. There is also a mismatch between engine speed and vehicle speed. Most small partners are unaware of this situation, but maintenance workers often use it when detecting faults.