The car engine tachometer is caused by the weight of the car's throttle, of course, also has a relationship with the gear.

Step on the accelerator, the higher the speed, the higher the fuel consumption. If the speed is too high, the red line of the car engine tachometer indicates that the engine is running too fast, and the oil supply from the oil pipeline has failed to keep up, the oil will be cut off, and the sound of the engine will be short and long.

The general speed is high, when the high-grade, can be more on the transmission higher gear operation. If you add gear at a low speed, the car requires acceleration, but the engine can't keep up, it will stall. If the speed is in the normal position, forced to reduce the gear, the car to slow down, but the engine is still in a high level of operation, with not out of the force will be converted into a high speed, speed will suddenly jump from the low to the high phenomenon.

It is to see above all idle speed is used, it is to hit catch fire to wait for water temperature to be normal later idle speed should be in commonly 800-1000 turn left and right sides; Next it is shift gear opportunity reference, control is in commonly 2000 turn left and right sides shift gear in time, rotate speed too high can waste oil, too low word car power is insufficient.