EVs allow for a different driving technique informally known as “one-pedal driving.” As the name implies, it allows the driver to simply use one pedal, the accelerator, to drive the car – once the technique is mastered, the driver never needs to use the brake, except when unplanned traffic requires a little more urgency.
In technical terms, what makes this possible is regenerative braking. When the driver needs to slow the car down, the electric motors are used “in reverse” to convert the car’s forward motion to electrical energy, as opposed to the typical application of converting the car’s electrical energy to forward motion.
Not all EV manufacturers allow for one-pedal driving, and those that do execute it differently. There’s no right or wrong way to implement (or not implement) this feature.
Harkening to Ghostbusters’ “Important Safety Tip,” new EV drivers shouldn’t discover one-pedal driving for the first time after they have taken delivery and are just leaving the dealer’s parking lot.
The Nitty Gritty Details of One Pedal Driving
This topic was not on my radar for discussion until it came to my attention via a social media post by someone who had never driven an EV before yet paid six figures for a new one. They were shocked when they lifted their foot off the accelerator and the car came to a stop in the middle of the road. Not the best time to learn about this feature.
Please understand: I am not disrespecting the new owner/driver (although shame to the dealer who sold this car yet couldn’t be bothered to give an overview of it with the new owner). However, I was once again reminded that we do not come out of the womb knowing everything, and to my discredit, I had forgotten what it was like to get behind the wheel of an EV for the first time. Since this column is focused on the new EV driver, let’s dive right in.
What Is One-Pedal Driving?
When you press the accelerator in an EV, you use electrical energy to make the car accelerate. Putting this into the language of your high school physics teacher, you are conserving energy by converting electrical to kinetic energy (forward motion).
If the car has any type of one-pedal driving, then releasing the accelerator simply reverses the process—converting kinetic energy back to electrical energy and then putting it back into the battery. It’d be a neat trick if an ICE-mobile could convert kinetic energy back into gasoline. But entropy happens (more physics for another day).
But John, you might be saying. That’s nice to know and all, but what does it mean for driving the car? The answer is… well, not much, or quite a lot, depending on who you ask.
I recall the first time I drove a modern electric car. It was BMW’s ActiveE, which was a test vehicle that was leased to a small group of individuals. At the time, I was building an electric Miata in my garage, but it wasn’t (yet) road worthy. Before I got behind the wheel of the BMW, I had read about the effects of one-pedal driving, but that didn’t mean I was actually prepared to experience it.
I took the car on a test drive. The dealer’s lot opened up to a freeway entrance. I quickly got up to freeway speed. Once at cruising speed, and without realizing what I was doing, I eased up on the accelerator just a tad. It was simply muscle memory telling the car that we had hit cruising speed so we could stop accelerating, but my foot was calibrated to the Honda I had been driving, not to this new one-pedal driving thing. The car slowed so much that it threw me into the seatbelt. BMW’s client advisor, sitting next to me, simply chuckled.
One-Pedal Driving Is That Different
Yes. The first time you experience it, it can unexpectedly throw you into your seatbelt. So, why then? Why include it?
Before answering that question, I’d like to say in defense of one-pedal driving that many (most?) people adjust after about 15 minutes. And then they love it. But not all. We’ll get back to them in a bit.
The reasons manufacturers include one-pedal driving is:
- They can
- It converts some kinetic energy back to the battery, increasing range
- It reduces wear on the friction brakes
- Once you get the hang of it, it makes for a simpler, more relaxed driving experience
The problem is, not everyone gets the hang of it, nor is one-pedal driving universally loved. Taking it a step further, the energy returned to the battery is typically in the single-digit percentage. The bottom line is that some manufacturers are not on board and do not offer one-pedal driving.
The consumer, therefore, is faced with the fact that not all EVs drive the same. Whether you care about one-pedal driving or couldn’t care less, as a consumer, you should be aware that what you are about to decorate your driveway with may or may not drive a bit differently than you’re used to. And you may or may not like it.
How Is a Toyota Like a Porsche?
Toyota and Porsche aren’t the only manufacturers that skip one-pedal driving, but I use them as an example to explain the spectrum of thinking on the topic.
Toyota simply wants to keep the driving experience as “normal” as possible so their customers don’t have to learn anything new. Porsche doesn’t offer one-pedal driving because they feel it isn’t as efficient as their implementation of the “blended brake,” which is when pressing the brake pedal activates both regenerative braking and friction brakes. The balance between the two depends on a number of factors, including how hard you press the brake.
Regardless of the reason, these two very different auto manufacturers have reached the same conclusion about one-pedal driving.
Many (most?) EVs will allow you to adjust the level of regenerative braking, but even when this customization is offered, some EVs may not provide the level of adjustment you want – the message here is caveat emptor. If you haven’t driven an EV before, drive one before you sign the paperwork. Better yet, ensure the car you’re considering has the adjustment range you want.
Anything Else I Need to Know?
Yes, and it turns out this is kind of a big one. The feel of “one-pedal driving” can change as a function of the battery’s state of charge (SOC). There is a good reason for this, but in my view, the only reason not to compensate for it is simply laziness on the part of automobile manufacturers.
I have mentioned in the past that the charging of the battery slows as it gets close to 100% SOC. We’ll go in-depth on why that is in the future, but for now, imagine it like filling a glass of water. You want it completely full, but without spilling a drop. As the water gets closer to the rim, you slow the water flow down to a trickle to prevent spilling. This is similar to charging a battery, except instead of spilling water, you slow the charge rate to avoid a fire.
With that background, it is a logical step to think of one-pedal driving’s regeneration as simply charging the battery. The problem is, if the battery is close to 100% SOC, you do not want to regen (charge) too fast. Some manufacturers, therefore, will limit regen between 80% and 100% SOC. That means the amount of regen you get is different at 50% SOC than it is at 100% SOC.
This can be a bit of a thrill when you have 100% SOC and pull up to your first stop sign expecting some regen to slow you down, but instead, you are scrambling to remember where the brake pedal is. Laugh all you want; it’s a thing. I can say for certain that Tesla, Lucid, and Jaguar all prefer to keep drivers extra alert by leaving them guessing on the amount of regen you might get. I’m exaggerating a bit to emphasize a point, but it is something to be aware of if you’re new to driving electric.
Other manufacturers (I’m looking at you, BMW) use software to blend in the friction brakes when the battery is near 100% SOC to keep the driving experience uniform regardless of the battery SOC. If I had Harry Potter’s wand, all manufacturers would do this.
Don’t Creep Me Out
Creep is another “feature” EVs lack compared to an ICE-mobile, unless the manufacturer delivers software that mimics it. This one “creeps me out,” pun intended, as I just don’t see the point. But we all have tastes and expectations, so it’s a good thing that creep, when offered, is optional.
Every ICE-mobile with an automatic transmission has a torque converter. This is a fluid coupling of the drivetrain to the transmission and, by design, it never completely disengages. This is why you have to hold your foot on the brake at a stoplight – otherwise the car would creep forward.
EVs don’t have a torque converter, but some drivers are accustomed to creep and prefer not to learn a new way to drive. So, some manufacturers have implemented a software mimic to creep, requiring the driver to keep their foot on the brake when at a complete stop. Not all EVs offer this option, though, so if this interests you, be sure to keep this in mind as you shop for your new EV.
What’s the Right Answer?
Returning to my personal experience, I adapted to one-pedal driving after about 5 miles of driving, and I love it. I even play a little game while driving, timing my stops just so, obviating the need to touch the brake. With an EV-driving husband exclusively owning EVs for over ten years, my wife, on the other hand, has never gotten used to it. She wouldn’t buy an EV for herself until she found one she liked that allowed her the adjustment that would mimic the ICE experience. Now she drives a Hyundai Ioniq 5. She also knows when I’ve been driving it because the regen is set to maximum.
There is no right or wrong way to drive an EV. Your way is perfect. Just make sure the car you’re considering is compatible with your way.
Next week we will discuss the myth that EVs are dirtier than Internal Combustion Engine (ICE)-powered cars.