F1 agrees to drop controversial 50/50 power unit split with 2027 rules tweaks

Further tweaks to Formula 1’s power unit regulations have been agreed, following the trial of the first round of changes in Miami last week, with the 50/50 power split between the battery and combustion elements dropped. 

As well as further refinements for the current season, more extensive updates for 2027 have been confirmed, including changes to hardware that were not practical for the short term.

The proposals were discussed today in an online meeting involving the FIA, F1, teams and power unit manufacturers as a follow-up to the similar gathering that took place on April 20.

The Miami package was generally well-received as a step in the right direction, although Max Verstappen described it as just a “tickle” with more needed.

Agreed in principle for 2027, there will be a nominal increase of around 50kW from the internal combustion engine [ICE] through a fuel flow increase, while the same power output will be reduced from the energy recovery system [ERS]. This will end the controversial 50/50 power delivery of the current power units.

However, these remain proposals only, with more detailed discussions with technical groups required before the final package is signed off. 

“I think honestly, it’s never easy to do a change during the season,” Ferrari boss Fred Vasseur said in Miami. “Because as soon as you want to change something on the regulation, you are impacting the relative performance of the car. 

“But I think for once that we were able to do, let’s say, good work, even if everybody wants to get more. But at the end of the day, I think we did a step forward, and I think it’s a good one.”

The gap since the last meeting and data gathered from Miami have created the opportunity for further study, which has been fed into today’s meeting.

The key longer-term elements are an increase in fuel flow – which, for example, would require future chassis to have a bigger fuel tank capacity – and bigger batteries.

There are also plans to trim downforce levels, although power units were the focus of today’s meeting.

“Hardware adjustments to the power unit in order to improve F1 in general, I personally think are required,” McLaren boss Andrea Stella noted in Miami.

“They will have to do realistically with the fuel flow to increase the power from the internal combustion engine, and I think they might have to do with harvesting more power than the power you actually deploy, because you spend much more time deploying electrical power rather than harvesting it. 

“So this can be rebalanced by harvesting to a larger power than we do today, like from 350, can we go to 400? Can we go to 450? And then I think we just need bigger batteries.”

Stella stressed that at this stage, 2028 was a more realistic target for the major hardware changes than next season. That would also need less support, under F1’s governance.

“If I think about these three requirements from a hardware point of view, and I see things from the perspective of a power unit manufacturer, I see this [will be] difficult for 2027,” he said. “Because the implication for the battery size and the implication for coping with higher fuel flow, they are normally longer lead time than the time available to go into the 2027 season.

“And actually, I would urge that possibly this conversation needs to be finalised. I would say before the summer break, to be in time to do it for 2028.

“And definitely, I would hope that that's the case, because while we have done a good job as an F1 community of looking constantly at improving the exploitation of the engine with what's available, I think we can extract more out of these regulations, but this will need some hardware tweak.”