Will the speed decrease when releasing the accelerator pedal?
2 Answers
For automatic transmission vehicles, when the speed reaches a certain level, releasing the accelerator pedal will cause the speed to drop rapidly. If the accelerator pedal is not pressed again, the vehicle will eventually come to a stop, as all vehicles rely on fuel to maintain normal operation. However, some high-end automatic transmission vehicles are equipped with a "cruise control" function, which is exclusive to automatic transmission cars. In such vehicles, when the speed reaches a certain level and the accelerator pedal is released, the vehicle will continue to travel at the preset speed. Here is more information: Automatic transmission cars: They usually use hydraulic transmission devices to replace the mechanical clutch of manual transmission cars, so there is no clutch pedal. When the engine speed is low, the torque transmitted by the fluid is limited and insufficient to propel the car forward. When the gear lever is placed in the drive position and the brake pedal is released, as the accelerator is pressed and the engine speed increases, the transmitted torque increases, pushing the car forward. If driving a manual transmission car: Compared to skilled drivers operating manual transmission cars, under the same driving conditions, automatic transmission cars generally consume about 6~10% more fuel. Automatic transmission cars have higher fuel consumption than their manual transmission counterparts of the same model, approximately 1 liter more per 100 kilometers. In terms of vehicle cost, the cost of an automatic transmission is higher than that of a manual transmission for the same model. The advantage of automatic transmission over manual transmission lies in its ease of driving.
When I first learned to drive, the instructor repeatedly emphasized that releasing the accelerator naturally leads to a decrease in speed—this is fundamental control. The reason is that the accelerator is connected to the engine's fuel supply system; releasing it reduces the engine's power output, allowing the vehicle to coast forward on the momentum it previously gained. However, there are various resistances on the road, such as air resistance pushing against the front of the car and tire friction against the ground, which gradually slow the vehicle down. On a straight highway, releasing the accelerator won’t cause an immediate drop in speed, but within minutes, you’ll notice deceleration—for example, dropping from 120 km/h to 80 km/h is quite common. On a downhill slope, the decrease might be slower or even result in slight acceleration, but the overall trend remains deceleration. During my practice, I deeply realized that coasting can save fuel since the engine operates at a lower fuel supply state. Remember this for safe driving: releasing the accelerator early instead of braking suddenly reduces the risk of accidents.
