Do Electric Vehicles Consume More Power at High Speed or Low Speed?
2 Answers
Electric vehicles consume more power at high speed. Electric vehicles are more energy-efficient at low speed and consume more power at high speed: The working efficiency of an electric motor in a pure electric vehicle is almost unaffected by its rotation speed, and it does not lose energy through a transmission. Therefore, pure electric vehicles are very energy-efficient at low speeds. When running at high speed, although the motor efficiency can be maintained at 80%-90%, air resistance increases with the square of the speed. The higher the speed, the greater the air resistance the electric vehicle needs to overcome, resulting in significantly higher power consumption at high speeds compared to low speeds. Pure electric vehicles can recover kinetic energy at low speed: Another technology that makes pure electric vehicles energy-efficient at low speed is kinetic energy recovery. During frequent deceleration at low speeds, the vehicle recovers energy each time and transmits it back to the battery. The most energy-efficient speed for a pure electric vehicle is low speed, with an energy efficiency of 80%-90%. Combined with 20% from kinetic energy recovery, the energy-saving effect is surprisingly good.
Electric cars consume more power at high speeds. The physics explanation is simple: as speed increases, wind resistance rises dramatically. When speed increases from 60 km/h to 120 km/h, wind resistance nearly quadruples, and the electric motor must output more energy to overcome it. At lower speeds around 40 km/h, wind resistance is much smaller, with rolling resistance and start-stop effects being the main factors. Although the initial acceleration consumes high power, it is brief. On average, high-speed driving demands more overall energy. From my experience, electric cars average around 15 kWh/100 km in city driving, while highway driving easily exceeds 20 kWh/100 km. My advice is to maintain a speed between 80 to 100 km/h—avoid speeding but also don’t drive too slowly. Additionally, ensure proper tire pressure and avoid excessive air conditioning to maximize efficiency and range.
