Do Electric Cars Have Transmissions?

The automotive industry is shifting toward electric vehicles as a more eco-friendly alternative to traditional vehicles with internal combustion engines (also known as ICE vehicles). As with any new technology, people have questions about how electric cars work and what components they include. One of the most commonly asked questions is whether electric cars have transmissions. The short answer is, yes, electric cars do have transmissions. That said, electric transmissions differ in a number of ways from those of traditional ICE vehicles. The main difference is that most electric cars use a single-speed transmission, whereas gas-powered vehicles use multi-speed transmissions.

In this article, we'll discuss the differences between an electric vehicle transmission and a traditional transmission. We'll also take a deeper look at the powertrain of an electric car, discuss what makes EV powertrains unique, cover any variations in designs, and speculate on the future of EV transmissions. For the purposes of simplification, we won't be discussing continuously variable automatic transmissions, or CVTs, which are physically distinct from a traditional ICE transmission but also offer multiple gear ratios.

All electric cars have some form of transmission, but manufacturers use different terms. An EV transmission can sometimes be referred to as a single-speed gear reducer (Nissan Leaf), single-speed fixed gear (Tesla Model 3), one-speed gearbox (Volkswagen ID.4), single-stage transmission (Mercedes EQS SUV), one-speed transmission (BMW iX) and more. Other terms for an electric car transmission include reduction gear or direct drive, but essentially they're all referring to the same thing. In essence, most electric cars use a single-speed transmission with a reduction gear mechanism, which helps to slow the high rpm — revolutions per minute — of the electric motor and match the rpm to the actual wheel rotation.

If you hear that an electric car has no transmission, it's likely referring to a vehicle with reduction gearing, which essentially performs the same functions as a transmission.

We have a more detailed discussion on how electric cars work in this article, so we're just covering the basics here. In a nutshell, every EV has one or more electric motors that use magnetic fields to convert electrical energy into kinetic energy, which sends power through a transmission and then to a differential to rotate the left and right wheels. Automakers will tune the balance of power and torque of an electric vehicle to tailor it to the specific needs of the vehicle. An electric pickup truck, like the Ford F-150 Lightning, would likely be tuned with higher torque for towing, while an electric sports car such as the Porsche Taycan would be tuned for higher horsepower to improve its overall performance.

Electric motors rev much higher than gas engines and inherently make maximum torque from zero rpm up to a fixed point. This enables them to reach top speed in a single gear. In contrast, combustion engines make their power at higher rpm and need multiple gear ratios to both reach higher speeds and avoid over-revving the engine.

An electric vehicle's transmission is much simpler than an ICE vehicle's multi-speed transmission. An EV transmission has a more compact shape and fewer moving parts, and it's likely to be more reliable and easier to maintain. An EV transmission can accelerate more quickly, quietly and smoothly than a non-EV transmission since it is neither shifting gears nor revving a loud gas engine.

Every vehicle, whether electric or ICE, experiences varying levels of drivetrain loss. This is the vehicle's inability to use all the energy that's produced by burning fuel or that's stored in the battery due to heat generation, friction in the transmission and drag forces. According to the U.S. Department of Energy, an EV's drive system is responsible for a 15% to 20% energy loss, compared to a 64% to 75% loss for a gasoline engine. This makes the EV significantly more energy-efficient than its gas counterpart.

Modern automatic transmissions on gas cars have anywhere between six and 10 speeds. There are numerous types, including a traditional torque converter automatic transmission, continuously variable transmission, dual-clutch transmission and manual transmission. All of these are more complicated, larger and potentially more expensive to produce and repair than a simpler electric car transmission.

Single-speed transmissions: Regardless of what an automaker calls its EV transmission, most are a single-speed transmission. Electric cars with two electric motors — also called dual motors — often have two transmissions, one on the front axle and another in the rear. Those still have one gear at each axle, but they work in unison and are still considered single-speed transmissions.

Two-speed transmissions: A two-speed transmission for an electric motor is more complicated than a single-speed and somewhat of a rarity. Years ago, when the original Tesla Roadster was being developed, the plans called for a two-speed manual gearbox. The design proved too complicated and the production vehicle ultimately used a single-speed transmission. At the time of publication, only the Porsche Taycan and the Audi e-tron GT are electric cars with two-speed transmissions. The first speed handles maximum acceleration, while the second speed delivers the top speed and greater efficiency during highway cruising. Most EVs are not efficient at highway speeds, but this second gear allows both cars to be the exception.

The Audi e-tron GT and all-wheel-drive versions of the Porsche Taycan actually have a set of two transmissions: a single-speed unit at the front axle and a two-speed unit at the rear. That doesn't mean that it is a three-speed transmission, however. Instead, each transmission has its own job. The front motor and transmission handle the day-to-day driving. When the driver engages Sport or Sport Plus driving modes, launch control becomes available and uses the first gear of the rear transmission for off-the-line acceleration and then the second gear kicks in to take the vehicle to higher speeds.

As Tesla learned firsthand, there is an added level of complexity that comes with multi-speed transmissions on electric vehicles. That's not to say that more gears aren't possible. Automaker Stellantis has shown a Jeep Magneto concept that features a six-speed manual EV transmission. Similarly, Toyota has filed patents for a new form of manual electric vehicle transmission that would offer the best of both worlds with a nonshifting automatic mode and a virtual manual mode. However, neither vehicle has yet to make it to production since the costs and complexity are likely high and the overall interest in manual transmissions these days is relatively low. Because of these factors, we expect single-speed EV transmissions to be the norm in the near future.

Electric car transmissions are different from conventional transmissions, and they are more efficient and easier to package and offer smoother acceleration. While almost every EV transmission is a single-speed automatic transmission, some manufacturers are experimenting with multi-speed automatics, and even manuals, to explore the limits of EV performance.