Despite the recent pullback from its ambitious electrification goals for road-going vehicles, Porsche is committed to the Formula E (FE) racing series for 2026-2027 and beyond with the “Gen4” or fourth generation of the Formula E racing car since the series debut in 2014. The Porsche 975 RSE is Porsche’s third iteration of its FE program—see the #271/April 2020 issue for a primer on the Formula E series and Porsche’s first 99X FE car of the Gen2 era, and the #294 October 2022 tech feature for an overview of the outgoing Porsche Gen3 99X.
Season 13 of the FE series begins in December 2026 and runs through August of 2027, with a busy 19-round race schedule. FE continues its format of racing only on temporary street circuits in major cities around the world, from Berlin to Tokyo to Miami to Jeddah in Saudi Arabia. The series has come a long way from the first season, in which battery technology limitations meant drivers needed to switch cars midway through the race. Energy management and recuperation are key strategies for success, and the recent mandatory pit stop for recharging has added another strategic element to doubleheader race weekends.
Porsche’s initial foray into FE in Season 6 of 2019-2020 had a slow start, with an eighth-place finish in championship points for both the manufacturer and lead driver, but the company’s vast experience in motorsports and deep pool of driver talent eventually paid dividends, with factory driver Pascal Wehrlein securing the 2023-2024 driver’s championship, and Porsche winning both the team and manufacturer championships in 2024-2025.
The 975 moniker does not follow Porsche’s usual sequencing of project numbers but instead pays homage to 2026 being the 75th anniversary of Porsche in motorsports. Much of the Gen4 car is standardized by the FIA for cost saving and parity of performance, but each subsequent generation of the race car has allowed the teams to develop more of their own components to optimize performance. Porsche plans to field a total of six 975 RSE cars, with four factory entries, and the continued presence of a customer team with two cars.
Key Gen4 Rule Changes
The FE Gen4 platform comes shortly after the debut of the Gen3 “Evo” introduced for the 2025-2026 season, which offered temporary all-wheel drive and a slight boost in power from 350 to 400 kW (469 to 536 hp). The Gen4 formula allows permanent all-wheel drive (AWD) and 600 kW (805 hp)
The Gen4’s headline power output of 600 kW (805 hp) is available only during qualifying, the standing start at the beginning of a race, or if a driver intentionally goes off the racing line in the designated area of the track to activate “Attack Mode”—the normal output during race conditions is 450 kW/603 hp. Top speed increases from 320 km/h (199 mph) to 335 km/h (208 mph). The FIA touts the Gen4’s 1.82-second 0-60 mph time as faster than a contemporary Formula One car’s 2.5 seconds.
Approximately 40 to 50 percent of the energy used per lap is derived from recuperation during braking, with up to 700 kW of recuperation possible (350 kW each for the front and rear axles). Despite the massive braking effect of the Gen4’s aggressive energy recuperation strategy, larger friction brakes are required to cope with the higher velocity at the end of each straight, with 275 mm (10.8 in.) discs on front and rear axles (Gen3 lacked rear mechanical brakes), along with a new brake-by-wire system.
The current Gen3 Evo was allowed part-time AWD for use during qualifying, race starts, and when Attack Mode is activated. The Gen4 formula features permanent AWD for improved traction in all conditions. Mechanical limited-slip differentials (LSD, see the #225/February 2015 tech feature for more info) have long been allowed in the FE series, but Gen4 rules allow the teams to develop electronically-controlled locking differentials in the vein of those used on road-going Porsche sports cars since the 991 era (e.g., Porsche Torque Vectoring Plus). Porsche has not released details of its specific differential setup for the 975 RSE, but given the importance of such differentials in Formula One, it is likely to be a key area of development amongst the teams as the Gen4 era progresses.
The standardized battery pack used by the Gen4 FE cars is referred to by organizers as a “Rechargeable energy storage system (RESS),” or a Lithium-ion accumulator, which refers to the capacitor-like nature of its battery cells. They are designed to be rapidly discharged and recharged during a racing lap rather than for ultimate energy storage capacity, as with the cells of most road-going EV battery packs. Manufactured by Italian firm Podium Advanced Technologies, the Gen4 battery packs weigh about 340 kg or 748 lbs and have a usable energy capacity of 51.25 kWh.
The Gen4 continues the FE stipulation of body and chassis as standard components, again developed and built by Spark Racing Technologies. The front bodywork and suspension components are standard for all the teams, while, as with the current Gen3 formula, the teams are free to develop their own
rear electric motor, pulse inverter, gearbox/differential, axle shafts, and rear suspension components. The Gen4 car is the first Formula E car with power steering, along with a wider cockpit for increased hand clearance.
In-house Development of Parts
For the Gen4 975 RSE, Porsche additionally developed the DC-DC converter and brake-by-wire system in-house, and as with the Gen3 cars, Porsche engineers wrote the operating software for these systems. Despite the increased number of in-house parts allowed, FE rules stipulate that this Gen4 parts package can only weigh 5 kg/11 lbs more than the previous package.
The current Gen 3 Evo car already achieves 97 percent efficiency from the battery to the driven wheels, with the engineers sweating out every fraction of a percentage along the way. For comparison, most road-going internal-combustion-engine (ICE) vehicles achieve barely one-third energy efficiency, while a modern Formula One race car might achieve 50 percent. Porsche claims the same efficiency rating for the Gen4 car, which is remarkable given the increased amount of power deployed and recuperated.
Porsche credits its Formula E experience as directly translating to improved performance of its electrified production vehicles. The silicon-carbide pulse inverter developed for the Porsche FE program made its production debut in the 2025 Taycan Turbo GT (see the #315/February 2025 drive feature) and has proliferated across the Porsche range from the Macan Electric to the 992.2 T-Hybrid sports cars (#324/February 2026).
Motorsport engineers at Weissach developed a direct oil cooling system for all current-carrying components of the Formula E drivetrain, which was recently introduced for the Cayenne S Electric and Turbo Electric SUVs. Conventional indirect cooling via water jackets necessitates a motor package 1.5 times larger than Porsche’s motorsport-derived direct oil-cooled version, which uses a fluid pump to circulate a special non-conductive oil directly through the motor windings.
Body & Chassis
A hallmark of the FE series since its inception has been simple bodywork packages with relatively low levels of aerodynamic downforce to save cost and promote closer racing. The FIA’s goal of increased power and performance for the Gen4 era has necessitated greater downforce. The Gen4’s larger front and rear wing elements, distinctive side blade elements, and redesigned underfloor combine to allow up to 150 percent more downforce than the Gen3 Evo. The higher-downforce package is used for qualifying, and an energy-efficient lower-downforce package is deployed during races.
The Gen4 car is larger than its predecessors in every dimension, with overall length increasing by 520 mm (20.5 in.) to 5,540 mm (218 in.), with wheelbase and width each increasing by about 100 mm (3.9 in.). The larger dimensions and battery pack result in a weight increase for the 975 RSE to 954 kg or 2,089 lb without driver—the minimum allowed weight with driver is 1,012 kg (2,231 lb).
The Gen4 cars will use a new spec tire developed by Bridgestone, replacing the previous Hankook versions. Slick tires are still not permitted for dry racing, but a version with shallower tread blocks is used in dry conditions, with a deeper-grooved wet-weather version deployed during heavy rain conditions. The new tire package is wider front and rear to improve traction—295 mm (11.6 in) section width in front and 330 mm (13.0 in) rear, increases of 30 mm (1.2 in) front and 15 mm (0.6 in) rear over the Gen3 Evo tires.
The higher power output with AWD traction, wider tires, and increased downforce are expected to make the Gen4 cars a full ten seconds faster per lap around most of the street courses in which FE compete—faster than the current Formula Two car in many cases—which will result in a large recalibration for drivers and teams.
Another key aspect of FE is a focus on sustainability, with the FIA mandating continual improvements in everything from recyclability of the cars and their components to minimizing carbon dioxide (CO2) emissions from race car/team transport (the FE series groups events by continent to cut emissions versus the constant crisscrossing of the globe by Formula One and its support series). The Gen4 car is designed to be 100 percent recyclable, with the chassis already being composed of 20 percent recycled materials. The FIA enforces strict requirements for component suppliers according to the ISO 14001 standards for environmental management systems for manufacturing processes.
The FIA had promised in-race fast charging of the battery since the debut of the Gen3 car in 2022, but technical issues delayed its realization until the 2025 Jeddah round of the 2024-2025 season. The so-called “PIT BOOST” is a mandatory pit stop during doubleheader race weekends—each car is required to come into the pit lane to receive a 30-second fast charge at 600 kW, which adds to the battery’s state of charge (SoC)—amounting to about 3.85 kWh in Gen3, and expected to rise to over 4.05 kWh for Gen4 cars. The PIT BOOST not only adds a strategic element to the race but also promotes the leading edge of fast charging technology.
Future Fast
While the broader automotive industry recalibrates its timeline for road-going electrification, Weissach’s dedication to Formula E demonstrates that Porsche continues to work to be a step ahead of the curve. When the lights go green for Season 13 in December, the 975 RSE will not just be fighting to retain Porsche’s championship status—it will be actively developing the high-performance DNA of the brand’s future road cars.
