The Oxford Advanced American Dictionary defines an automotive transmission as “the system in a vehicle by which power is passed from the engine to the wheels.” This means that the simple answer to the question about electric vehicles having transmissions is yes. However, EVs don’t have the same kind of transmission as combustion vehicles, which either need multiple or continuously variable gears to ensure a mix of good acceleration, fuel efficiency, and the long-legged character necessary for relaxed driving at highway speeds.
Electric vehicles do have transmissions because power has to be transmitted from the motor to the wheels, but they don’t have multiple speeds. The simple reason behind this fact is a mix between EVs being able to deliver the three aforementioned characteristics (acceleration, efficiency, and cruising ability) with a just one gear ratio, as well as the fact that making a reliable multi-gear transmission for EVs has proven challenging.
Why Are There Hardly Any Multi-Speed Transmissions In EVs?
You probably know the story of Tesla testing out multiple-gear transmissions in first-generation Roadster prototypes, and how the idea was abandoned because these gearboxes kept failing. Jay Leno remembers this happening during a Roadster test drive when he recalls actually hearing the sound of the teeth on the gears inside the transmission being stripped when the vehicle shifted under hard acceleration.
Tesla abandoned the idea of putting a two-speed transmission in the Roadster and sold it with a single-speed box. This one-gear approach became the standard in the industry, but the two-speed was revived by another manufacturer many years after Tesla’s failed attempt with the Roadster.
Nowadays, you will see geared transmissions in combustion cars that have been turned into EVs. Retaining the ICE vehicle’s original transmission is the most affordable way to do an EV conversion since you reuse much of what the car already had and you don’t need to come up with an entirely new transmission system. However, in the vast majority of these EV conversions that retain the stock gearbox, the vehicle is left in one gear (often third) since it provides a good blend between acceleration and high-speed efficiency.
The fully electric Jeep Wrangler Magneto 2.0, which we experienced off-road in 2022, featured a modified Dodge Charger Hellcat-sourced six-speed manual transmission that made for a very different EV driving experience.
Which EVs Have Multiple Speeds?
The Porsche Taycan and Audi E-Tron GT share a platform and feature a two-speed automatic gearbox on the rear motor, designed by German transmission specialist ZF. The Ingear two-speed EV transmission from Canada-based automotive supplier Inmotive
Mercedes-Benz is also believed to introduce a two-speed gearbox in an all-new electric CLA sedan expected to arrive by the end of 2024, as well as other subsequent new EVs.
Probably the coolest multi-speed EVs were early Formula E racers. These single-seater racers had a sequential five-speed paddle-operated gearbox, and you could hear them go up through the gears as they accelerated down the straights, but they were abandoned after the competition’s first season.
How Do Single-Speed EV Transmissions Work?
Since EVs can do just fine with a single-speed transmission, the gearbox itself is much simpler and more compact (and often integrated into a one drive unit along with the electric motor). Electric traction motors can spin at over 10,000 rpm and they feature a reduction mechanism to gear them down.
As a simple visualization, the motor’s output shaft is connected to a small cog, which spins a larger cog. This brings rpm down, increases torque, and makes the power usable in an automotive application. Electric motors also produce peak torque from almost zero rpm and maintain it until very high in the rev range, and this is another factor that allows EVs to work just fine with only one gear that takes them from a standstill up to top speed.
There’s also no need to decouple the motor from the wheels, like in an ICE vehicle. Electric motors don’t need to idle, so you don’t need a clutch to get going, and you usually want regenerative braking to kick in when you lift off the accelerator pedal, so it’s fine for the motor and wheels to always be connected.
However, most EVs still have a clutch or some sort of decoupling mechanism to enable coasting (which is sometimes more efficient than using regenerative braking) and free-wheeling when in neutral (to allow you to push the vehicle if need be), and this varies depending on the manufacturer, platform, and type of electric motors used.
What Are Simulated Gears?
The idea of having simulated gears in an EV is a very polarizing one, both among car fans and probably the automakers themselves too. That partly explains why so few manufacturers have tried to do it, even though trying to mimic a combustion engine’s noise and characteristics seems like one of the most obvious ways to try to make EVs more engaging and exciting.
So far, only Hyundai has been bold enough to offer actual simulated gears in a production car, the Ioniq 5 N, which even gives you an ICE-like rev counter on the driver’s display when you select the fake manual mode. It allows you to go up through eight simulated gears, and every time you shift, you not only see an rpm drop but torque is also cut momentarily to simulate an actual mechanical cog swap. It doesn’t make the car any quicker, but it’s a fun feature that owners may enjoy from time to time.
Dodge is another manufacturer that could introduce simulated gears in its EVs similar to Hyundai but also pair them with an exterior sound generator similar to the one in the Abarth 500e.
Toyota went one step further than everyone with its simulated gears and showed footage of it testing a fully electric car with a third pedal and an actual stick shift. In its demonstration, Toyota showed off a Lexus UX-based prototype as it reached a simulated redline in each gear and how the driver pressed the clutch and then slotted the shifter into the next gear.
The system has been designed to mimic a sputtering if you let off the clutch too quickly, and the vehicle will even simulate stalling. Toyota envisions this as a solution that you can turn on when you want a more engaging driving experience, then disable it when you just want to get from one place to another. BMW is also reportedly considering developing something similar to Toyota’s simulated stick shift, but the Bavarians also want the stick to vibrate, for that extra level of immersion.
With so many differing visions among automakers and automotive parts suppliers, it is difficult to anticipate if there is a future for actual or simulated gears in an EV. Let us know what your take is on all this in the comments below: do you think shifting gears has a place in the EV world?