Is it more fuel-efficient to keep the accelerator pedal pressed or to press and release it alternately while driving?
4 Answers
When driving, it is better to press and release the accelerator pedal alternately rather than keeping it deeply pressed continuously, as this significantly increases fuel consumption. The correct method for pressing the accelerator pedal is: adjust the movement of your foot on the pedal. Place the heel of your right foot on the floor of the driver's compartment as a pivot point, and press the pedal with the ball of your foot, using the ankle joint's flexion and extension to press and release the pedal. Key considerations for pressing the accelerator pedal include: 1. Press and release the pedal gently and smoothly; 2. Coordinate the release of the clutch with pressing the accelerator promptly and precisely; 3. Select the appropriate gear to ensure the engine operates mostly at medium RPM and with a wider throttle opening for fuel efficiency; 4. Before stopping or turning off the engine, release the accelerator pedal first and avoid revving the engine abruptly.
After driving for most of my life, I've found that the most fuel-efficient way is to maintain a steady throttle and drive at a constant speed. Pressing and releasing the pedal may seem like it saves fuel, but each time you accelerate again, more fuel is injected, and the fluctuating engine load actually consumes more fuel. On highways, it's best to maintain a steady speed of around 90 km/h, and in the city, try to anticipate traffic lights to reduce braking. A car is just like a person—steady jogging is more energy-efficient than sprinting and resting. I remember on my last long trip, I deliberately kept the throttle steady and got an extra 80 kilometers out of a full tank. Nowadays, new cars come with instant fuel consumption displays, so you can observe that fuel consumption is lowest at constant speeds. If you really want to save fuel, you'll have to work on your ankle and learn to apply even pressure.
From the perspective of engine working principles, combustion efficiency is highest under steady-state conditions. When you press the accelerator pedal deeply, the electronic control unit increases fuel injection to ensure torque output, causing the air-fuel ratio to deviate from the ideal state. Conversely, when releasing the throttle to coast, although fuel injection stops, the vehicle's kinetic energy is wasted as heat. Repeated acceleration and deceleration cause frequent changes in engine operating conditions, leading to increased overall fuel consumption. Test data shows that maintaining a steady speed of 60-80 km/h results in 20% lower fuel consumption compared to repeatedly accelerating and decelerating over the same distance. Manual transmission drivers are advised to pay attention to shift timing to avoid high load at low RPMs, while automatic transmission drivers can utilize cruise control for assistance.
I drive a hybrid, but the principle is similar - maintaining a steady speed is definitely more fuel-efficient. When accelerating, the system has to overcome inertia, like suddenly pedaling hard on a bicycle; whereas cruising at a constant speed is like maintaining a steady rhythm. I remember when I first started driving, I also believed coasting by releasing the throttle saved fuel. But later, checking the instant fuel consumption gauge showed that every time I accelerated again, it would spike to 20L/100km, while steady cruising only required 6L. After each acceleration, you'd need to drive quite a distance to offset the fuel consumption peak. The sensible approach is to anticipate road conditions: release the throttle and coast 500 meters before a red light, then gradually accelerate when the light turns green to avoid flooring it. On highways, using adaptive cruise control is much more stable than manual pedal control.
