More weight, less energy, no fire extinguisher: Extended technical regulations for the Gen4 era of Formula E published

At its final meeting of 2025, the FIA World Motorsport Council approved amendments to the technical regulations for the 2026/27 Formula E World Championship. This means that further details are now known about the Gen4 cars, which are currently being tested and are expected to contest their debut season from the end of 2026.

Around a year before the planned debut race of the fourth-generation Formula E cars, the FIA has revised the technical regulations for the new vehicles and made further adjustments. There are a number of changes, including the battery capacity and the minimum weight of the cars.

After e-Formula.news analysed the new regulations presented back in June, you can now find a comprehensive update on the new rules here.

Article 3.1 Homologation form

The fire extinguishing system is no longer one of the parts homologated by the chassis supplier Spark.

For suspension elements, tethers, driveshafts, low-voltage looms and cooling and hydraulic pipes, manufacturers are no longer obliged to comply with Spark's volume specifications.

Article 3.2 Software

Manufacturers must now be able to prove at any time which software version is running on the individual electronic boxes. In addition, various functions of the boxes must be documented.

Article 5.1 Minimum weight

The minimum weight of the Gen4 cars has now been set at 1,028 kg. Previously, this was 1,012 kg.

Article 5.3 Ballast

The screw size with which ballast must be attached to the floor below the monocoque has been reduced from M8 to M6.

Article 6.3.2 Specification of the rear engine

The reference to the fact that it is not permitted to have a switchable device that can modify subsequently the own resistance of the AC phases bus, has been deleted.

Article 7.5 Power and energy limitations of the battery

The amount of energy available in the race has been reduced from 55 to 51.25 kWh.

Article 8.4 Emergency stop switch

The manual switch for the fire extinguishers has been removed from the list.

Article 8.5 Switches for the fire extinguishers

This item has been completely removed from the technical regulations.

Article 8.8.3 Data collection

The technical list specifying the manufacturers' sensors whose data must be transmitted to the FIA data collection system has been added.

Article 11.2 Hydraulic braking system

If the brake pressure exceeds 130 bar, braking is considered an "emergency case" and may be reported to the stewards.

Article 12.1 Hydraulic system

The maximum pressure limit of 130 bar no longer applies to the power steering system.

Article 15.1.2 Halo system

As in Formula 1, a fairing may now also be fitted to the halo system in Formula E.

Article 16.1 Fire extinguishing system

This article has been largely deleted and renamed: It is now called Battery Flooding System, which was previously sub-article 16.1.2.

Article 16.5 Safety tethers

There have been some editorial changes regarding the tethers used to hold the wheels to the monocoque in the event of a suspension failure. Editorial changes have also been made to the section describing the tethers used to attach the rear impact structure to the car's gearbox. However, there are no changes to the content.

Drawing 8 Functional circuit diagram

In this drawing, the two emergency stop switches (see Articles 8.4 and 8.5) have been removed.

Drawing 12 Maximum volume for designing handles

This drawing, which was initially missing from the first publication of the regulations, has been added.

Drawing 13 Manufacturer maximum volumes

This drawing was also missing when the regulations were first published and is now available.

Appendix 1 Suspension members

The pushrod on the rear suspension of the cars developed by the manufacturers may now be mounted a maximum of 60 cm above the base plate of the car instead of 50 cm.