Do Electric Cars Have Transmissions? | EV Transmission Guide

The transmission in a car, also known as a gearbox, uses gears to transfer power from the engine to the drive wheels. Your internal combustion engine needs this transfer of power because the engine can only operate within a specific rotation per minute (RPM) range that doesn’t line up with the RPM of the wheels. Several types of transmissions exist in modern cars. The automatic transmission claims the top spot in vehicles manufactured today, followed by the continuously variable transmission (CVT). Manual transmissions were installed in only 1% of new cars, and can be found primarily on sports cars.

The automatic transmission comes with as many as 12 gears (which often need to be serviced regularly). When the engine RPM gets too high, the automatic transmission shifts gears, allowing the engine to operate at a lower RPM while providing steady power to the wheels. This process continues as you accelerate and works in reverse as you slow down. 

The CVT uses a belt or chain and pulley tensioning system to adjust power to the drive wheels instead of actual gears, resulting in the same steady output without overtaxing the engine. Manual transmissions put the decision in the driver’s hands, allowing the operator to switch gears manually upon reaching the top of the powerband. Driving enthusiasts prefer the manual transmission, as it lets them “feel” the machine as they operate it.

In an electric vehicle, the transmission comprises a single gear in most cases. For example, the Porsche Taycan and the original Tesla Roadster came with two-speed gearboxes, although Tesla upgraded the gearbox to a single gear after production.

Why Do Electric Cars Need Only a One-Gear Transmission?

The answer lies in the differences between the internal combustion engine and the electric motor. Both provide rotational power to the wheels, but in drastically different ways. The internal combustion engine works by igniting fuel inside the cylinders. The explosion moves the pistons, which rotate the crankshaft. The crankshaft connects to the transmission, which transfers that rotational force to the drive wheels.

The mechanical downside to combustion engines lies in their limited rotations per minute — too few RPM and the engine stalls out. Too much RPM and the engine can damage itself from turning too fast. Every engine has a sweet spot or range called the powerband that produces enough rotational force to move the wheels but not too much to cause damage. Most production cars have a range between 800 and 7,000 RPM. Because of this powerband range, an internal combustion engine needs multiple gears to achieve the speeds driving requires. 

An electric motor operates at a much broader powerband. Electric motors achieve peak torque at zero RPM and can operate safely at up to 20,000 RPM. Electric motors still need a gear to allow the motor and wheels to turn at different speeds, but this wide RPM range allows a single gear to transfer power from the motor to the drive wheels over the entire speed range.

Can Electric Cars Have Multiple Gears?

Yes, the Porsche Taycan has a two-speed gearbox, but most electric motors only use a single gear. We find electric vehicles with all-wheel drive using two electric motors, one for the front axle and another for the rear axle. These motors use different gear ratios to achieve different results.

For example, the smaller front motor and gear on many electric vehicles were designed for efficiency, while a larger rear motor and gear were engineered for power. As a result, the car might send more power to the rear when accelerating to get up to speed faster. Once the vehicle achieves its cruising speed, it can divert power to only the front motor for better efficiency.

In some cases, the rear motor goes to sleep entirely. The motor continues to spin without engaging the gearbox. When you press the accelerator, the gearbox wakes up to access that torque immediately and imperceptibly.

What Does the EV Transmission of the Future Look Like?

No one knows how the gearbox in an electric vehicle will evolve. Only recently have manufacturers begun to put serious money toward research and development. We only have to look at the history of the internal combustion engine to see how little we know about the process. When the manual transmission was overtaken by the automatic transmission and then again by continuously variable and dual-clutch transmissions, no one saw these advancements coming until they arrived.

We can expect the electric vehicle industry to evolve rapidly over the next decade, as the R&D money continues to flow. For example, new battery chemistry could change the landscape, as could improvements in a multispeed transmission. Or, the single gear paired with an electric motor could be the pinnacle of efficient power and speed.

The first electric vehicles targeted efficiency. Manufacturers wanted to offer a green alternative, but it left driving enthusiasts desiring more. As technology advanced, more manufacturers have focused on making their electric cars, trucks, and SUVs fun to drive. They’ve implemented performance engineering, taking design elements from racing and off-road divisions and parts manufacturers to improve power, control, and speed. Modern electric vehicles have come a long way in the last 10 years. Who knows how far they’ll go in the next 10, but we wait with anticipation for what comes next.

At United Chevrolet Buick GMC in Jacksonville, Illinois, we are excited about the future of electric vehicles. Already, we realize how the popularity of the efficient Chevy Bolt has changed the way people view electric utility vehicles. For drivers looking for off-road performance, the GMC Hummer EV comes in a pickup or an SUV model, further changing how we look at electric performance.

As new models arrive, we want to be your source for electric vehicles. So we invite you to browse our inventory online or stop by for a hands-on demonstration of what the power of electricity in a car, truck, or SUV can do for you.