"The current Formula 1 MGU-K uses a radial flux design, not axial flux.
Here’s why:
Radial flux machines (rotor inside, stator outside) are preferred in F1 because they offer:
Lower rotational inertia, which is critical for ultra-fast response times (milliseconds) during gear shifts and energy deployment.
Better cooling and packaging for high-speed operation (up to 50,000 rpm).
Axial flux machines (disc-shaped) are generally more compact and can have higher torque density, but they have greater rotational inertia, which makes them less suitable for F1 where rapid transient response is essential. This was explicitly noted in technical discussions: axial flux designs are considered inferior for F1 because they slow response and could cost lap time during shifts. [f1technical.net]
So, the MGU-K in F1 is a high-speed permanent magnet synchronous machine with a radial flux configuration."
Yes. You are right and I was wrong in my quoting of the Formula 1 MGU-K motor flux direction, my quoting was unintentionally the other way round.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 10 Dec 2025, 15:19
by JonoNic
Would a driver who is trying to charge his depleted battery be hoping for some yellow flag zones? Then he charge aggressively without being overtaken. Is this a viable stratergy?
Would a driver who is trying to charge his depleted battery be hoping for some yellow flag zones? Then he charge aggressively without being overtaken. Is this a viable stratergy?
Sent from my SM-S9380 using Tapatalk
I would say yes. Generally, everyone will be able to recover a lot of energy during yellow and safety car conditions - there will be no differential.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 10 Dec 2025, 23:37
by djos
The sim racing crowd are already making 2026 mods to simulate performance.
This video has some interesting deployment experiments with the new PU Config.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 11 Dec 2025, 00:08
by hsg
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
well ....
they will be braking earlier because the aero downforce is less so grip is less
so usefully more time is available for regeneration at 350 kW (though grip and regen power will fall as the car slows)
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
Electric devices don't make these decisions. The regs are the way they are because someone chose to make the regs this way. Really all the stopping early stuff is because they removed the MGU-H, the other way we had to charge the battery.
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
There are two ways: They could just brake earlier as you mentioned in order the recover 350 kW under braking for longer.
Or they could recover up to 250 kW under full throttle and still have around 150 kW of Powertrain power available for driving the wheels (assuming a power output of 400 kW for the ICE alone).
I guess, the second one is better for the laptime.
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
There are two ways: They could just brake earlier as you mentioned in order the recover 350 kW under braking for longer.
Or they could recover up to 250 kW under full throttle and still have around 150 kW of Powertrain power available for driving the wheels (assuming a power output of 400 kW for the ICE alone).
I guess, the second one is better for the laptime.
It is highly unlikely for a 2026 formula 1 car to recover up to 250 kw under 'full throttle' and still have around 150 kw of powertrain power available simultaneously. Energy recovery primarily occurs during braking phases, not under 'full throttle'.
Is it true that driver will must brake earlier on straights to fill the battery, in short, is it possible they need to drive "slower" because of this stupid electric engines, and at the end make better lap time?
There are two ways: They could just brake earlier as you mentioned in order the recover 350 kW under braking for longer.
Or they could recover up to 250 kW under full throttle and still have around 150 kW of Powertrain power available for driving the wheels (assuming a power output of 400 kW for the ICE alone).
I guess, the second one is better for the laptime.
It is highly unlikely for a 2026 formula 1 car to recover up to 250 kw under 'full throttle' and still have around 150 kw of powertrain power available simultaneously. Energy recovery primarily occurs during braking phases, not under 'full throttle'.
I am more and more under the impression that you might be kind of an AI, that simply keeps repeating itself again and again without updating its own model.
The specific rules have already been presented to you again and again in this very thread.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 11 Dec 2025, 15:02
by the EDGE
I’m a little confused… Would there ever be a time a driver would want to turn his ICE into a generator to store up electrical power?
Surely this would be wholly inefficient, not only would you have to carry more fuel which would obviously increase your lap time, without the MGU-H, you be wasting the vast majority of its energy as you did so
Perhaps this has already been explained further back, it I’d appreciate it if someone could explain, in simple language
I’m a little confused… Would there ever be a time a driver would want to turn his ICE into a generator to store up electrical power?
Surely this would be wholly inefficient, not only would you have to carry more fuel which would obviously increase your lap time, without the MGU-H, you be wasting the vast majority of its energy as you did so
Perhaps this has already been explained further back, it I’d appreciate it if someone could explain, in simple language
Yes, you want to be able to use as much power as you have available. You're effectively using fuel to do that.
Or ask yourself this question: Would you rather race with a 200hp engine with 50l of fuel or a 400hp engine with 100l of fuel when the max allowable power is 400hp?
I’m a little confused… Would there ever be a time a driver would want to turn his ICE into a generator to store up electrical power?
Surely this would be wholly inefficient, not only would you have to carry more fuel which would obviously increase your lap time, without the MGU-H, you be wasting the vast majority of its energy as you did so
Perhaps this has already been explained further back, it I’d appreciate it if someone could explain, in simple language
Yes, you want to be able to use as much power as you have available. You're effectively using fuel to do that.
Or ask yourself this question: Would you rather race with a 200hp engine with 50l of fuel or a 400hp engine with 100l of fuel when the max allowable power is 400hp?
Well, that would depend on what the math says, but that’s my point, I don’t understand how that would mathematically be possible, surely burning petrol to generate electricity is wholly inefficient. That is What I want explaining
Your example would require 100% Efficiency, and that is not possible
I’m a little confused… Would there ever be a time a driver would want to turn his ICE into a generator to store up electrical power?
Surely this would be wholly inefficient, not only would you have to carry more fuel which would obviously increase your lap time, without the MGU-H, you be wasting the vast majority of its energy as you did so
Perhaps this has already been explained further back, it I’d appreciate it if someone could explain, in simple language
Yes, you want to be able to use as much power as you have available. You're effectively using fuel to do that.
Or ask yourself this question: Would you rather race with a 200hp engine with 50l of fuel or a 400hp engine with 100l of fuel when the max allowable power is 400hp?
Well, that would depend on what the math says, but that’s my point, I don’t understand how that would mathematically be possible, surely burning petrol to generate electricity is wholly inefficient. That is What I want explaining
Your example would require 100% Efficiency, and that is not possible
Correct, and it is a stupid idea, but they wanted a stronger MGUK component along with shitcanning the expensive MGUH. So these are the regulations they get to work with.
... surely burning petrol to generate electricity is wholly inefficient. That is What I want explaining
F1 is a series of rolling-start drag races
if drag races were energy-limited eg ....
it would be better to do the first 500 ft at 8000 hp and the second 500 ft at 4000 hp (rather than 1000 ft at 6000 hp)
burning for electricity, storing, then re-using it is (in isolation) about 90% as efficient as simultaneous 'burning & turning'
but the ES allows F1 to be run as a series of the above hypothetical drag race so there is a time benefit overall
time benefit in cars built to the mandatory minimum weight of course