2025/2026 Hybrid Powerunit speculation

[Cs98]

Christian Horner:
“Obviously one of the biggest weight additions as well is the cell weight. The size of the battery is colossal for these 2026 regs.”

https://www.autosport.com/f1/news/why-h ... /10491959/

Why does he keep saying that? The SOC requirements have not changed, so one would expect the cells to be the same as specified for the current regulations - that is, between 20kg and 25kg.

Addition items are included in the ES minimum weight of 35kg.

From 2022 rules:

ENERGY STORE (ES)
The difference between the maximum and minimum state of charge of the ES may not exceed 4MJ at any time the car is on track.

5.5.3 The total mass of the part of the ES that stores energy, i.e. the cells (including any clamping plates) and electrical connections between cells, must be no less than 20kg and must not exceed 25kg.

From the 2026 rules:

5.4.8 The difference between the maximum and the minimum state of charge of the ES may not exceed 4MJ at any time the car is on the track.

5.19.9 The minimum mass for the ES Main Enclosure and the elements residing inside of it (articles 5.19.7 and 5.19. is 35.0kg. The procedure which will be used to determine this value may be found in the Appendix to the Technical and Sporting Regulations.

The referenced articles:

5.19.7 The following elements of the power unit must be fitted inside the ES main enclosure and be installed within the ERS reference volume:
a. ES elements as defined in items 26 (ES) and 29 (HV elements) of Appendix 3 to these regulations.
b. The HV safety elements and sensors defined in items 27 (DC sensor, IMD) and 28 (safety devices) of Appendix 3 to these regulations.
c. Any DC-DC converter and its connection to the ES HV DC bus. Includes active parts, enclosure, brackets and supports.
d. CU-K. Includes active parts, enclosure, brackets and supports.
e. HV DC connections between ES and CU-K/DC-DC converter. Includes all conductors, insulation, EMC screening, mechanical and thermal shielding.

5.19.8 In addition to the components listed in Article 5.19.7, the following elements may also be fitted within the ES main enclosure:
a. Low voltage Power Distribution Board (PDB).
b. PU Electric pump Driver units.
c. Low Voltage systems passive protection devices - Fuse box.
d. Low Voltage looms exclusively used: for PU functionalities or power supply chassis devices.
e. Any Electronic Box devices exclusively used for PU functionalities.
With the exception of wiring or any mechanical supports for these components, no additional elements may be fitted in the ES main enclosure.


So why would the battery be heavier? Bigger CE?

Wattage and heat. You take a small battery (same size they have now) and run 350kW through it, the battery will be toast in no time. So the more power you have, you need a bigger battery just for longevity and heat management.

[saviour stivala]

Doomsaying talk prior to every rule change in formula 1 was always the norm. RB agreed and signed off on the new power unit formula. Their talk - 'Having to change gear down before end of straight' is political. Their real problem is the CHASSIS RULES are still up in the air. From its start the new formula was engine dominated and everybody went - 'this is dumb', now-a-days it became chassis dominated, and for those dominating it is great while it lasts, but are now feeling unsure if they would still be able to produce a dominant chassis in 2026, so they start push-out politics to maneuvers things around. Running out of battery power at some long end of straights is not going to be a new thing as it is there nowadays. Normally it is compensated for by adjustment of how much full battery deployment after corner exit tappers off once car reaches full speed, but this adjustment depends on how good the car aero efficiency is.

If any team can be confident of delivering a top rate chassis it's Red Bull. They've been consistently doing it for many years.

cceleration is king.

As far as F1 is from its traditional features currently, wheel fairings would not be out of place. Just be forwarned, everyone. Newey designed the Gran Turismo X cars... 13 years ago.

By "designed" you mean vaguely specified some attributes that felt right to him.

I have no doubt that Red Bull can deliver a top rate chassis, and that is why I believe they will do all in their power to keep the formula as is - chassis dependent.

[saviour stivala]

Verstappen "F1 needs to serously look at this (the 50/50 power unit rule) before it is to late and made it clear he is worried that the engine will be a dominant factor in the performance agaim''. I have no doubt of his genuin worries as I have no doubt that they at RB wants the formula to remain chassis dependent.

[vorticism]

They could go heavy on rear weight bias (although the published regs afaik make no mention of this). 70:30. 80:20?

If they reduce the wheelbase then the weight bias would move further to the rear.

Win win? More rear axle braking, reduce temptation for front axles motor(s), and it would also effectively force boxier sidepods like those seen from the 80s-00s. No more coke bottles, or at least...



Smol front wheels would also help driver visibility. Would they be so bold? And would complement the need for reduced front axle unsprung weight with a more rear shifted weight bias.




That said the LENGTH is largely irrelevant when internals and chassis design determine weight distribution. You could still have looong cars with a high rear weight bias. And you could even still have tall tires in the front, just reduced to pizza cutters.

But would it help much when during braking most of the load shifts to the front?

Yes, for the same reason mid engine all wheel drive cars usually have a rear biased torque distribution. Bowlby on the Deltawing:

The car is unique in that 60 percent of the braking occurs at the rear wheels, but that doesn’t mean we could ignore the front. https://pfc.parts/motorsports/deltawing/

By "designed" you mean vaguely specified some attributes that felt right to him.

That is the very definition of the term, in some sense.

[Cs98]

Pat Symonds on 2026:
“When we conceived the car, the idea was to have front axle recovery. The manufacturers ditched that, so that made our life really difficult. But it doesn't make it impossible."

Makes it pretty bad though doesn't it. That's half your regen power out the window pretty much.

More:
"“The performance profile of a 2026 car in simulation now doesn't look terribly different to 2023.

“So all of this thing about hitting the top speed in the middle of the straight, it's not like that anymore.

"Performance profile", vaguery. My guess is it's going to be an abomination on the aero side to try and make up for the deficits of the engine.

[wuzak]

Symonds added that, while teams are mindful of the challenges of the 50/50 split between combustion power and electrical energy, there was always the acceptance that the regulations would evolve once they had been published.

“We needed to get a set of regulations out for the engine, and put some energy management numbers in there,” he said.

“They were very immature. We knew that they wouldn't work and we knew that they needed to be developed. And where we've got to in the nine months since is transformational.

“The performance profile of a 2026 car in simulation now doesn't look terribly different to 2023.

“So all of this thing about hitting the top speed in the middle of the straight, it's not like that anymore.

“You have to bear in mind that these cars don't reach top speed at the end of the straight anymore; so all this thing about changing down gears on the straight simply isn't true.”

https://www.autosport.com/f1/news/f1-ch ... /10492684/

So there is scope to change the ICE/MGUK balance before the final regulations are published.

It would be nice for the FIA to publish some example of how they see the power being deployed, the speeds cars can achieve, etc.

While Symonds says that the current cars don't achieve to speed at the end of the straight, they are pretty close to the end and they will peak much earlier in 2026.

[vorticism]

Why does Formula 1 have a Chief Technical Officer and why is it Pat Symonds?

[wuzak]

Why does Formula 1 have a Chief Technical Officer and why is it Pat Symonds?

The answer to the first is that the FIA needs to develop new rules without over reliance on the teams.

The answer to the second is: not a clue.

[NL_Fer]

So using your numbers and lets assume there is enough fuel to generate to the max 350kW wherever possible (yes I know there isn't enough). The ICE runs at 350kW for 90% of the lap. For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels). During braking (10% of the lap) there is 350 kW going to the ES.

So total storage is:
Laptime x [(350 x 20% x 1/2) + (350 x 10%)] = Laptime x 70 kW

The average power available for the remaining 70% is therefore
350 + (Laptime x 70)/(Laptime x 70%) = 450kW

Of course the stored energy would be deployed in bursts with output power varying from 350 - 700 kW during that 70% of the lap.

I think 20% of the lap requiring less than 350kW is optimistic.

It would be funny to se an F1 car go around Lowes Hairpin at Monaco at 50 or 60km/h with the ICE at WOT and the MGUK recovering energy.

Well that are still manual transmission, so assume they will be at low or medium rpm at the hairpin. So yeah loud, but still rumbling low. This also limits the possibility of the ICE delivering 350Kw constantly, it will be lower at low rpm. So even with 20% partial and off-throttle, it won’t be charging 350kw even all that 20%.

[Tommy Cookers]

Well that are still manual transmission, so assume they will be at low or medium rpm at the hairpin.
This also limits the possibility of the ICE delivering 350Kw constantly, it will be lower at low rpm. So even with 20% partial and off-throttle, it won’t be charging 350kw even all that 20%.

the ICE torque is constant below 10500 rpm
for 350 kW the MGU-K will need proportionately increased torque when rpm falls below 10500 rpm
the permitted generation is capped so the torque is capped (at roughly double the normal) below c.5500 rpm

increased K torque is increased K current
10500 rpm-worth of voltage and current may be preferable to excursions halving that voltage and doubling current
though we know Honda now generates into the low rpm region (though we don't know if eg they double the current)

[NL_Fer]

Well that are still manual transmission, so assume they will be at low or medium rpm at the hairpin.
This also limits the possibility of the ICE delivering 350Kw constantly, it will be lower at low rpm. So even with 20% partial and off-throttle, it won’t be charging 350kw even all that 20%.

the ICE torque is constant below 10500 rpm
for 350 kW the MGU-K will need proportionately increased torque when rpm falls below 10500 rpm
the permitted generation is capped so the torque is capped (at roughly double the normal) below c.5500 rpm

increased K torque is increased K current
10500 rpm-worth of voltage and current may be preferable to excursions halving that voltage and doubling current
though we know Honda now generates into the low rpm region (though we don't know if eg they double the current)

Bu this rule:

5.4.4 Below 10500rpm the fuel energy flow must not exceed EF(MJ/h)=0.27*N(rpm)+ 165

This would limit the torque generated by the ICE, to prevent the ICE to reach full power at lower RPM?

[CaribouBread]

https://www.autosport.com/f1/news/fuel- ... /10493187/

Fuel burn set for F1 return as result of 2026 engine plan

Speaking at the British Grand Prix, Mercedes F1 engine chief Hywel Thomas, said that manufacturers have long known about the fuel burn aspect.

"Absolutely that will be a thing," he said. "We will be running the engine when the driver is not asking for much torque in order to charge the battery.

"It was well understood when we were coming up with these regulations that that was going to be a part of them. And, with the fuel being sustainable fuel, it was considered that that was an acceptable and relevant approach to that problem."

----
Although there was no firm evidence yet about just how much noisier the 2026 engines will be, all indications pointed towards a much-improved situation.

"We haven't got any measurements, and haven't done anything like that," added Thomas. "But surely with the removal of the MGU-H, even though we have still got a turbocharger, it won't be removing as much of the energy as we're currently doing.

"We know the combustion engine will be less efficient and so that will, by physics, mean that there's more noise."

___________
They will have less fuel available, the engines will be less efficient, they will burn fuel for electric power - all while maintaining similar power levels? Make it make sense.

[wuzak]

Although there was no firm evidence yet about just how much noisier the 2026 engines will be, all indications pointed towards a much-improved situation.

"We haven't got any measurements, and haven't done anything like that," added Thomas. "But surely with the removal of the MGU-H, even though we have still got a turbocharger, it won't be removing as much of the energy as we're currently doing.

"We know the combustion engine will be less efficient and so that will, by physics, mean that there's more noise."

___________
They will have less fuel available, the engines will be less efficient, they will burn fuel for electric power - all while maintaining similar power levels? Make it make sense.

The turbo may take out less energy than now, but there will be less exhaust energy before the turbine.

So, the improved exhaust noise is speculation. If the ICE had the same fuel flow and power as now, then it would be better.

[mzso]

Fuel burn set for F1 return as result of 2026 engine plan

I guess right now they use the fuel without burning it...

[mzso]

I wonder how likely it is for the PU regulations to be amended. Two team leaders at least spoke up about it.

I wouldn't mind if they added an MGU-H as a standard supply component, and avoid all that foolishness of the engine running just to run the K...