2027 Formula 1 engines to deliver more energy as turbo and battery rules change
The power unit regulation changes approved for the next two Formula 1 seasons are proving to be more extensive than initially expected. To increase the output of the internal combustion engine, the FIA has acted not only on the permitted fuel energy flow but also on turbocharger boost pressure, which will return to levels similar to those seen in 2025.
Alongside revising the balance between the combustion engine and the hybrid system, the governing body has also decided to increase battery capacity. That decision will require manufacturers to invest in new development work that was not originally planned, all while remaining within the constraints of Formula 1’s engine budget cap.
Larger and more powerful batteries
One of the most significant changes for the coming years has largely gone unnoticed. According to the updated regulations, battery capacity will increase from the current 4 MJ to 4.5 MJ in 2027, before rising again to 5 MJ in 2028.
This will allow teams to deploy more electrical energy and keep the electric motor delivering power for longer periods. However, it will also require greater energy recovery throughout each lap. To support this, the maximum charging power will increase from 350 kW to 375 kW in 2027, before reaching 400 kW the following year.
Overall, Formula 1 batteries will become both larger and more powerful over the next two seasons, inevitably increasing their size and weight. Despite this, the FIA has not revised the minimum weight requirements. The battery pack will continue to have a minimum weight of 35 kg, while the complete power unit will remain at 185 kg in 2027 before increasing slightly to 187 kg in 2028.
The regulatory updates also extend to the software side, giving manufacturers greater freedom in their energy management strategies. The FIA has approved an increase to 10 MJ of recoverable energy during installation laps, formation laps and Safety Car periods in races, as well as during slow laps and pit exit laps in qualifying.
In addition, the FIA has removed the requirement to progressively reduce electric motor power once the car exceeds 290 km/h. That rule had originally been introduced for safety reasons, amid concerns that the new generation of cars could reach excessively high top speeds. In practice, however, teams naturally concentrate electric power deployment at the beginning of straights to reach maximum speed as quickly as possible.
One important restriction will remain in place. Teams will still be prohibited from cutting electric power instantly and will instead be required to reduce it progressively.
Higher turbo boost pressure
The second package of changes focuses on the internal combustion engine, with the aim of extracting more power and rebalancing the relationship between the thermal and electrical components of the power unit.
The FIA has revised the permitted fuel energy flow, effectively increasing the amount of chemical energy that can be introduced into the engine. In 2027, the maximum limit will rise from 3,000 MJ/h to 3,150 MJ/h, before increasing further to 3,400 MJ/h in 2028. That could eventually require larger fuel tanks.
However, the increase in combustion engine power will also come from changes to the turbocharger itself. Maximum turbo boost pressure will increase from the current 4.8 bar absolute to 5.0 bar in 2027, before climbing to 5.5 bar in 2028.
Those figures will bring Formula 1 back to boost pressures similar to those used by the previous generation of hybrid power units. Although there was no formal boost limit under those regulations, turbochargers typically operated between 5.5 and 6.0 bar absolute pressure.
To reach the agreed performance targets, further hardware changes will arrive in 2028. Several geometric parameters of both the turbine and compressor will be revised, with increases to the impeller diameters as well as the axial length of the turbocharger assembly.
Budget cap challenge for manufacturers
The technical regulation changes make it inevitable that engine manufacturers will have to update their power units, creating additional challenges under Formula 1’s engine budget cap. When the original regulations were drafted, manufacturers were not expecting to develop an entirely new battery specification for 2027.
However, the updated regulations now explicitly allow manufacturers to carry out the necessary work to comply with the new technical requirements. Looking further ahead, the FIA has also planned a new homologation window for updated power units in 2028, enabling every manufacturer to respond to the even more significant regulation changes scheduled for that season.
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