Freedom for manufacturers, Pit Boost remains: Technical regulations for Formula E Gen4 car published

The technical regulations for the 2026-27 season were adopted at the meeting of the FIA World Motorsport Council. The detailed regulations subsequently published by the FIA reveal many details about the fourth-generation Formula E cars that were previously unknown. e-Formula.news has analysed the 72 pages of the regulations for you and gives you an overview of the biggest differences compared to the current cars.

The rough key data for the new Formula E cars has been known for several months: the maximum power will increase from 350 kW to 600 kW, and the energy recovery from 600 kW to 700 kW. The cars will also have a larger battery and power steering for the first time.

A look at the technical regulations confirms this: chassis manufacturer Spark is making more systems available to all teams than was previously the case. In addition to the aforementioned power steering, this now includes hydraulic brakes on the rear axle, which were omitted from the Gen3 car in favour of a more powerful energy recovery system.

Later, an emergency braking system was retrofitted, which may be used if there is no recuperation on the rear axle due to a problem with the rear powerrtrain or the battery. Also new are retaining cables in the suspension, which are intended to ensure that the wheels do not come loose uncontrollably in the event of the wheel suspension breaking off during a crash.

Manufacturers may develop further components

But manufacturers are also given more freedom in development: they are now allowed to develop active differentials for the front and rear axle. Two different systems are still permitted: a mechanical limited slip differential, which partially or completely locks in the event of wheel spin so that more power goes to the wheel with more grip. Alternatively, a viscous coupling system consisting of discs in a viscous oil is also permitted. If the wheels rotate at different speeds, friction is created which slowly transfers power. The disadvantage: it reacts more slowly than a mechanical limited slip differential. What is new is that the differentials can now be actively locked - electrically or hydraulically.

The brake-by-wire system on the front axle, which is still a standard part from chassis manufacturer Spark in the Gen3 cars, can now also be developed by the manufacturers themselves. This is an electronically controlled braking system in which sensors detect the position of the brake pedal and transmit it to control units, which then activate the brakes. Also new: the FIA now requires manufacturers to install a microphone in the rear housing of the powertrain.

At the front of the floor the leading edge is angled to work with the fences to create local downforce in outwash.
At the rear a long diffuser ends the flat floor, working with beam wing.
Its likely more powerful, than the exaggerated diffuser used to date. pic.twitter.com/KpDPCm0Ak6

— Craig Scarborough (@ScarbsTech) June 11, 2025

Front engine becomes more important

The maximum power output of the drives increases to 600 kW. A maximum of 350 kW may still be used on the rear axle. The front engine, on the other hand, will be significantly more powerful: its maximum output will increase from the current 50 kW to 250 kW. The higher energy recovery is also achieved via the front engine: instead of 250 kW, this may put a maximum of 350 kW of energy into the battery during braking. In contrast to the current cars, where the front powertrain only delivers power to the front wheels at the start of the race, in Attack Mode and during qualifying duels, the Gen4 car has permanent all-wheel drive.

What was also previously unknown: the Gen4 cars will also again have a Pit Boost. The amount of energy during pit stops with fast charging is set to increase by around five per cent, from the current 3.85 kWh to 4.05 kWh. The batteries, which will be supplied by Podium AT in future, will have a maximum usable energy quantity of 55 kWh in race mode - a significant increase compared to the 38.5 kWh that the drivers currently have available for the races.

The technical regulations also reveal the dimensions of the Gen4 cars: at 5.54 metres, the new vehicles will be 52 cm longer than their predecessor model. The wheelbase (3080 mm instead of 2970.5 mm), width (1800 mm instead of 1707 mm) and weight will also increase significantly: the new vehicles will weigh in at 1012 kg. In comparison: the Gen3 Evo cars currently weigh 862 kg, next season it will be 863 kg.

Tyres & rims will be wider

Formula E will continue to rely on all-weather tyres with a diameter of 18 inches. However, these will be significantly wider, especially on the front axle: the width of the tyres from the new supplier Bridgestone will be 295 mm instead of the previous 265 mm. The difference at the rear axle is not so big, with the width changing from 330 mm to 345 mm. The rims must therefore also be wider: Instead of 10 inches (front) and 12 inches (rear), these will be 11.5 and 13 inches wide respectively in future.

The camber of the tyres prescribed in the regulations is also changing: while the current camber must be in the range of -1° to -4°, the new cars will differentiate between the front and rear axles. At the front, the permitted range is between 0° and -4°, at the rear between 0° and -3°. The fact that neutral camber is now also permitted opens up new setup options, for example for better traction or less tyre wear.

An official date for the presentation of the new Gen4 car has not yet been set. There is speculation that it could be shown to the public for the first time at the end of July as part of the season finale in London.