How Formula E Rewrote the EV Playbook

See the Technologies That Took Formula E From Car Swaps to 700kW Regen

Image Source: DS Penske, used by permission

By Nicolette Emmino for Mouser Electronics

Published July 31, 2026

In the early days of Formula E—an international, fully electric street racing series—drivers would have to switch vehicles midway through a race because the car’s battery could not provide enough power for the full race distance. Today, a single Formula E car can complete a race while delivering even more power and recovering energy at rates of hundreds of kilowatts through regenerative braking and years of innovation.

That progress, achieved in just 12 years, is possible because engineers worked to extract more performance from every part of the vehicle. The most obvious explanation for the current generation of Formula E vehicles is better batteries, as battery technology has greatly improved since Formula E’s debut. But the road from mid-race car swaps to today’s high-performance electric race cars is a story about rethinking nearly every major subsystem in the vehicle, from inverters that control power delivery to the motors, cooling systems, gearboxes, and regenerative braking systems.

Many of the technologies developed and refined in Formula E have moved outside the racing series. Over the past decade, Formula E has been a proving ground for electric vehicle (EV) technology. Their implementations helped accelerate innovations in power electronics, motor design, sensing, charging, and energy management.^[1] Some technologies were used solely in the competitions, but others were enhanced and validated under racing conditions before being adapted to commercial EVs.

Formula E’s evolution goes beyond how fast the vehicles complete a lap, demonstrating how it has pushed the technologies into the future of electric transportation.

The Race for Efficiency

Formula E’s progress has been driven by two goals that don’t always work well together: propelling an electric race car around a circuit faster while using less energy.

Those two objectives have dictated the direction of the championship. Battery technology has advanced over the past decade, but many of Formula E’s biggest technological successes have come from improving how efficiently energy moves through the vehicle after it leaves the battery.

“The championship started in the first four seasons with drivers requiring two cars to complete a race (Figure 1),” says Phil Charles, Deputy Team Principal, DS Penske. “With the introduction of the Gen2 car, that changed to a single battery and a single car per race, even as power and energy consumption increased.”^[2]

Figure 1: The Gen1 Formula E car introduced all-electric racing to top-tier motorsport but required drivers to swap vehicles during races due to battery limitations. (Source: DS Penske, used by permission)

In addition to battery chemistry improvements that helped make a single-car setup possible, engineers were reducing losses throughout the drivetrain, increasing energy recovery, improving thermal management, and tweaking the systems that control how power was delivered to the wheels.

Today’s Formula E cars produce more power than their predecessors and use energy more efficiently. These improvements have taken years of development across the inverter, motor-generator unit (MGU), cooling systems, drivetrain, and regenerative braking systems.

Advances That Shaped the Modern Formula E Car

One of the most meaningful changes to Formula E cars occurred inside the powertrain inverter. The inverter converts the battery’s DC power into the AC power the motor needs, making it a key factor in drivetrain efficiency.

Notes Charles, “Formula E was at the forefront, and very much pioneered the early adoption and development of silicon carbide as a switching substrate material in the powertrain inverter.”

Silicon carbide (SiC) devices switch faster and more efficiently than traditional silicon. As a result, SiC devices reduce power losses while improving overall system performance. Since Formula E’s inception, SiC technology has moved from an emerging technology to a key component of many modern EV powertrains.

But, according to Charles, the performance and efficiency gains had to do with more than just the semiconductor devices.

“Ever-improving gate driver and better analog-to-digital signal conditioning componentry have allowed Formula E teams to multiply their switching speeds for improved efficiency in the inverters and have facilitated better control to target and harmonic suppression,” he says.

Faster switching speeds also introduce additional challenges by increasing electromagnetic noise throughout the vehicle. Engineers worked diligently to improve electromagnetic interference (EMI) protection.

“It then became a game of ‘Whac-A-Mole’ trying to chase and stop various other chips—initially in the inverter itself, but then also on the car as a whole—from losing functionality as they got exposed to the noise,” adds Charles.

Over time, as power electronics evolved, other advances were made in the MGU, specifically through revised winding designs that allowed more copper to be packed in the stator. Increasing the amount of copper reduced electrical losses and improved efficiency. This improvement may seem incremental, but Formula E’s technological progress is built on dozens of small gains like these, all contributing to better overall performance.

Advances in motors and power electronics also improved drivetrain design. Initially, some of the teams used twin pancake-shaped motors with two or three gears available in the gearbox. But as efficiency improved, the need for multiple gear ratios disappeared.

“Flattening of the MGU efficiency against [the] speed curve saw the need for internal combustion engine (ICE)-familiar multiple gear ratios to be deleted,” says Charles.

This change enabled much greater optimization of gear-tooth geometries and the flow around the gears.

As teams worked toward improved motor performance, thermal management became another important focus area.

“Significant cooling improvements have allowed far stronger-, but narrower-, operating-range rare earth neodymium magnets to be used on the MGU rotor,” says Charles.

Neodymium magnets create magnetic fields that interact with the motor’s stator to generate torque. Stronger magnets can improve power density, but are more sensitive to temperature. Improving the cooling systems allowed for the tighter thermal control needed to take advantage of higher-performance motor designs.

Managing temperature became a bigger part of the overall performance equation and was not simply about preventing components from overheating.

According to Charles, “You need to calculate the best compromise for the components you choose and then prioritize cooling the performance-critical components into the ideal range in the races.”

Balancing these factors can affect cooling-system weight, radiator size, aerodynamic drag, and packaging. These same factors now influence the design of commercial EVs, as thermal management affects charging speed, efficiency, power delivery, and long-term battery health.

All of the efficiency improvements led to a reduction in cooling requirements, enabling smaller pumps, less pipework, shared cooling systems, and more compact packaging. Improved capacitor technology enabled a smaller inverter design. The overall result was a drivetrain that was lighter, compact, and even more capable.

Maximizing Every Watt

The hardware improvements implemented since 2014 solved many challenges, but teams still had to figure out how to use the available energy efficiently over the course of a race.

In traditional motorsports, refueling replenishes expended energy, but Formula E teams operate within a fixed energy budget. Every time a driver accelerates, brakes, or performs an overtaking maneuver, it affects how much energy remains at the end of the race.

Determining the most efficient way to use that energy may appear mathematically simple. Engineers can calculate how much energy should be used during acceleration, recovered during braking, and then determine the ideal balance between lap time and energy consumption.

“We do generate a lap time against energy target frontier plot, and we put thermal cycle corrections on top,” Charles explains.

But races don’t always follow the ideal model, as drafting behind a vehicle can change aerodynamic drag, overtaking requires more energy, and traffic and collisions will constantly alter the energy equation.

“Once you get into the race, and the car ahead gives you a tow (less drag and, therefore, you brake from a higher speed for free), or the cars ahead slow you down when they collide or overtake each other, then doing the ‘linear ideal race’ completely goes out of the window,” says Charles.

These challenges have made energy management one of the key aspects of Formula E competitions. One important tool in that process is regenerative braking. Regenerative braking converts kinetic energy into electrical energy when a vehicle decelerates and returns it to the battery. Instead of the energy dissipating as heat, as in conventional braking systems, the vehicle recovers it and uses it later.

Regenerative braking has continually expanded the cars’ capabilities throughout Formula E’s history.

“Generation 3 introduced a front powertrain and therefore from this point, we had the opportunity to recover energy from both axles when we braked the cars,” says Charles.

This increased the amount of energy that could be returned to the battery during a race. But the rear powertrain remained more efficient because the teams developed it, whereas the front unit was a standardized component.

Teams also had to consider tire limitations. Charles explains that a tire “can’t deliver you lots of [regenerative] torque if it is off the ground, and it isn’t so happy if you ask it to accelerate the car to the side and slow the car down in the straight-ahead vector at the same time.”

The amount of regenerative braking that can be applied depends on tire grip, weight transfer, steering angle, and vehicle balance. The distribution of regenerated energy between the front and rear axles must be managed, alongside stability and performance.

“This means the team’s [regeneration] strategy needs to optimize the recovery torque bias as the car transfers load forwards and takes vertical load away from the rear tires and takes account of the driver’s steering inputs at the same time,” says Charles.

The importance of energy recovery will be evident in the Gen4 vehicle, which will debut in Season 13, coming in December 2026. The Gen4 car will demonstrate significant performance improvements, increasing regenerative power from 600kW to 700kW and peak qualifying/Attack Mode traction power from 350kW to 600kW, with full-time all-wheel drive.^[3]

Jumping to 700kW of regenerative capability shows how important energy recovery has become to maximizing Formula E performance within a fixed energy budget.

From Formula E to Production EV

Many of the technologies that helped improve Formula E performance over the last decade have also influenced commercial EV development.

“There are many electronic innovations that started or were proven out in Formula E,” says Charles.

According to Charles, such innovations include SiC power electronics, capacitor technologies, inverter components, switching devices, processor technology, gate driver circuitry, current-sensing technologies, and other electronics used in modern electric drivetrains. MGU improvements, gearbox developments, and lower-viscosity gearbox lubricants have also been adopted in production vehicles.

In addition to powertrain components, the Formula E testing grounds provided insights into other technologies. During the Gen3 era, Formula E removed the hydraulic brakes from the rear axle, relying on regenerative braking for rear-axle deceleration while retaining front braking systems. Doing so reduced weight and increased energy recovery, but also required engineers to develop lightweight backup systems capable of maintaining safe braking performance if the electronic systems failed.

“Looking further ahead, the lessons learned in Formula E … may well facilitate new ideas on how to slow the car without large backup hydraulic brakes,” says Charles.

While traditional braking systems remain necessary in today’s road vehicles, the work achieved in Formula E illustrates how regenerative braking could potentially take a larger role in future vehicle architectures. Increased energy recovery could improve vehicle efficiency, reduce component weight, and possibly decrease the amount of brake material released into the environment.

The Road Ahead

Moving from the Formula E cars that once required mid-race vehicle swaps in 2014 to the Gen4 race cars arriving in 2026 represents 12 years of engineering development focused on extracting performance from every watt of energy. Many of the lessons learned influence the EVs that are on public roads, signaling Formula E’s impact far beyond a checkered flag.

Sources

[1]https://evmagazine.com/technology/formula-e-shaping-future-electric-cars
[2] Phil Charles, interview by Nicolette Emmino, June 2026
[3]https://fiaformulae.com/en/news/755451/the-history-of-formula-e-s-race-cars-gen1-2-3-to-gen3-evo-and-gen4