Understanding One-Pedal Driving in Electric Cars
One of the key features of electric cars that has gained popularity is one-pedal driving. But what exactly does it mean, and how does it differ from driving a traditional combustion car? Let’s delve into this concept and explore whether it’s something you might want in your electric vehicle.
Electric cars, like the award-winning Kia EV9, utilize electric motors to propel them forward. In the case of the EV9, there are two electric motors generating a total of 283 kilowatts and 516 pound-feet of torque. These motors draw their energy from a 99.8 kilowatt-hour battery, which excites electromagnetics in the stator, causing the wheels to turn and propelling the vehicle from zero to 60 mph in around five seconds.
But what sets one-pedal driving apart is what happens when you release the accelerator pedal while coasting. In this situation, the magnetic fields within the electric motor create a resistive force that slows down the vehicle. This process turns the motor into an electric generator, allowing it to recapture energy and increase the car’s range through regenerative braking. Although not all of the energy expended can be recaptured due to factors like friction, this feature still contributes to extending the vehicle’s range.
The Kia EV9 offers adjustable levels of regeneration, which can be accessed through paddles on the steering wheel. By selecting different levels, you can control how much regenerative braking occurs when you lift off the accelerator pedal. In one-pedal mode, as you gradually release the pedal, the car noticeably and dramatically slows down in proportion to how much and how quickly you lift off. This linear relationship allows for precise control over speed and deceleration, enabling you to bring the vehicle to a complete stop without touching the brake pedal.
While most electric vehicles have some form of one-pedal mode, it’s important to note that not all vehicles creep forward when you come to a complete stop. In some instances, it’s necessary to touch the brake pedal for safety reasons. The ability to stop quickly depends on various factors such as motor power, battery charge, software tuning, and wheel size.
It’s worth mentioning that all electric vehicles also have traditional friction brakes, which use metal rotors and pads to bring the car to a stop. However, when using these brakes, the kinetic energy generated while driving is wasted as heat, negatively impacting the vehicle’s range. To address this, modern electric cars incorporate blended braking, where a combination of regenerative and friction braking is applied based on speed and stopping distance.
So, what are the advantages and disadvantages of one-pedal driving? On the positive side, at low speeds, one-pedal driving maximizes efficiency and range by recapturing as much energy as possible during stops or slow-downs without wasting any to friction heat. While it may not allow you to exceed the EPA estimate significantly, it provides an easy way to get closer to that mark.
However, during high-speed cruising, maintaining precise pedal pressure for an extended period can be fatiguing. In such cases, switching to coasting mode might be more efficient. Studies have also shown that improper use of one-pedal driving can contribute to car sickness if the pedal inputs are not smooth or if the vehicle’s software is not properly calibrated.
Ultimately, one-pedal driving is a toggle feature in most vehicles, including the Kia EV9. It is recommended to give it a try and see how it feels. If it doesn’t suit your preferences or driving style, you can simply turn it off.
In conclusion, one-pedal driving offers distinct advantages and disadvantages in electric vehicles. It optimizes efficiency and range at low speeds but may not be as suitable for steady-state cruising. Understanding the capabilities and limitations of one-pedal driving can help you make an informed decision about when to utilize this feature in your electric car.
For more in-depth information on the Kia EV9 and other electric vehicle technologies, be sure to visit cnet.com, where you’ll find comprehensive reviews and insightful articles.