Performance
Retarder is only an auxiliary braking device, emergency braking and stopping still need to apply the brakes. The size of the retarder power has nothing to do with the engine speed, only with the drive shaft speed (car speed), but the engine speed will affect the speed of the water cycle, the engine speed is too low, the retarder water temperature can easily rise, beyond the limit, the retarder will drop the torque or quit, affecting the retarder use time and effect. So constant speed gear, the engine speed should generally be maintained at 1500 rpm or more. The power of the retarder is not affected when the gearbox is in neutral, only the engine speed is in idle when in neutral, only about 800 rpm, the water circulation is too slow, the retarder will quit after a few dozen seconds of use, so the retarder cannot be put in neutral when the gearbox is in use. In an emergency (non-slippery or turning conditions), you can directly pull the retarder in the highest gear to achieve the role of fast braking, will not damage the retarder. However, due to the rapid rise in water temperature, the retarder will exit at high temperature within ten seconds or so and lose braking power.
