2025/2026 Hybrid Powerunit speculation

[Tommy Cookers]

... if the MGUK is weaker than the ICE it can never fully arrest full-throttle ICE power...
... MGUK recovery ... Will it even be part-throttle or just extra, extra lean burn in that scenario? ....

the MGU-K can increase its current (torque) for full power at rpms below 10500 (2014-25 caps this torque at 5775 rpm)
2026 caps WOT generation at 250 kW - so much reducing ICE arrest scope

increased lean burn seems imo unlikely as they have dumped the 10% ethanol and have instead 3% methanol only

[vorticism]

Thanks both. How is ICE thermal efficiency affected when producing below peak ICE power? F.e. in the part-throttle charging regimes, when the engine is producing 100 or 200 hp or whatever to be absorbed by the MGUK, how reduced is the TE of the ICE compared to the peak power it was primarily designed to make? And in these low power output modes can they utilize leaning of the a:f ratio, in addition to, or in replacement of, use the ITBs to limit power output. Tommy, you are suggesting we might have seen peak dilution ratios in the current formula. Unless there is still development potential in the realms of CI, wave front ignition (whatever it's called), stratification, etc., within the limits of the injector, ignition, and fuel tech imposed by the regulations.

[gruntguru]

The MGU-K will not ''brakes'' the ICE with 150kw when the ICE is putting out 400kw.

Time to put an end to this nonsense.
2026 TECHNICAL REGULATIONS. https://www.fia.com/sites/default/files ... -06-24.pdf
.
1. This is the energy flow diagram published in the above technical regulations. Note the arrow in the yellow circle indicating energy can flow between the ICE and the MGU-K in either direction.

.
2. This is the technical regulation on part throttle fuel limits. Why would you need to limit the fuel flow at reduced PU output - when the driver is already limiting the power with his right foot. The answer is "because the ICE is permitted to make more power than the driver demand - with the excess going to the ES via the MGU-K".

.
3. This is a table showing permissible fuel energy flow for four values of "engine power" ("PU power"?) using the formula above. For simplicity I have assumed 50% TE at all outputs. Note that at only 218 kW driver demand, the maximum 3,000 MJ.hr is available - i.e. full ICE output is available - but only 218 kW is going to the rear wheels - the remaining 199 kW is going to the MGU-K.

[saviour stivala]

The MGU-K will not ''brakes'' the ICE with 150kw when the ICE is putting out 400kw.

Time to put an end to this nonsense.
2026 TECHNICAL REGULATIONS. https://www.fia.com/sites/default/files ... -06-24.pdf
.
1. This is the energy flow diagram published in the above technical regulations. Note the arrow in the yellow circle indicating energy can flow between the ICE and the MGU-K in either direction.
https://i.imgur.com/aDHTMHk.png
.
2. This is the technical regulation on part throttle fuel limits. Why do you need to limit the fuel flow at reduced PU output - when the driver is already limiting the power with his right foot. The answer is "because the ICE is permitted to make more power than the driver demand - and the excess sent to the ES via the MGU-K".
https://i.imgur.com/rpqNu90.png
.
3. This is a table showing permissible fuel energy flow for four values of "engine power" ("PU power"?) using the formula above. For simplicity I have assumed 50% TE at all outputs. Note that at only 218 kW driver demand, the maximum 3,000 MJ.hr is available - i.e. full ICE output available - but only 218 kW going to the rear wheels (surplus 199 kW going to the MGU-K)
https://i.imgur.com/wMG6lTY.png

''Time to put an end to this nonsense'' Far from it. The 2026 formula 1 regulations depicts a bidirectional energy flow arrow between the ICE and MGU-K through a newly simplified power unit that removes the MGU-H. The MGU-K will now have a dual function: It harvests kinetic energy from braking to store in battery, and it can also receive energy from the ICE to deliver power to the drivetrain, creating a more interconnected system.

[dren]

The MGU-K will not ''brakes'' the ICE with 150kw when the ICE is putting out 400kw.

Time to put an end to this nonsense.
2026 TECHNICAL REGULATIONS. https://www.fia.com/sites/default/files ... -06-24.pdf
.
1. This is the energy flow diagram published in the above technical regulations. Note the arrow in the yellow circle indicating energy can flow between the ICE and the MGU-K in either direction.
https://i.imgur.com/aDHTMHk.png
.
2. This is the technical regulation on part throttle fuel limits. Why do you need to limit the fuel flow at reduced PU output - when the driver is already limiting the power with his right foot. The answer is "because the ICE is permitted to make more power than the driver demand - and the excess sent to the ES via the MGU-K".
https://i.imgur.com/rpqNu90.png
.
3. This is a table showing permissible fuel energy flow for four values of "engine power" ("PU power"?) using the formula above. For simplicity I have assumed 50% TE at all outputs. Note that at only 218 kW driver demand, the maximum 3,000 MJ.hr is available - i.e. full ICE output available - but only 218 kW going to the rear wheels (surplus 199 kW going to the MGU-K)
https://i.imgur.com/wMG6lTY.png

''Time to put an end to this nonsense'' Far from it. The 2026 formula 1 regulations depicts a bidirectional energy flow arrow between the ICE and MGU-K through a newly simplified power unit that removes the MGU-H. The MGU-K will now have a dual function: It harvests kinetic energy from braking to store in battery, and it can also receive energy from the ICE to deliver power to the drivetrain, creating a more interconnected system.

[Zynerji]

delete

[wuzak]

I have to ask, if the limit of energy recovery per lap is 8.5MJ (for some tracks it will be reduced) and the energy recovery comes only from braking, where will teh additional recovery come from for tracks like:

Albert Park: ~8.5s braking, 2,975KJ possible recovery (ie not even 3/4 of the battery capacity)
Red Bull Ring: ~8.6s braking, 3,010KJ possible recovery (just 3/4 of the battery capacity)
Monza: 9.25s braking, 3,237kJ (ie just over 3/4 of the battery capacity)
Silverstone: ~11s braking, 3,850kJ - still haven't filled the battery
Jeddah: ~11s braking, 3,850kJ - still haven't filled the battery
Singapore: ~17s, 5,950kJ (can fill the battery 1.5 times, but still not teh maximum 8.5MJ)
Monaco: ~19s, 6,650kJ (getting closer)
Baku: ~19s, 6,650kJ (7 of the braking events are classified as hard, 2 medium, 3 light)

These are data for the current cars.

The 2026 cars will have less downforce and grip so will brake for longer, but won't brake as hard. The amount of time that the maximum 350kW can be recovered may not be much greater, as they run out of grip.

The above times are for all braking events in a lap. That includes light brushes of the brakes in some corners.

Monaco, for example, has only 1 really heavy braking zone, out of the tunnel into the chicane. And that lasts for 2s.

[Zynerji]

I have to ask, if the limit of energy recovery per lap is 8.5MJ (for some tracks it will be reduced) and the energy recovery comes only from braking, where will teh additional recovery come from for tracks like:

Albert Park: ~8.5s braking, 2,975KJ possible recovery (ie not even 3/4 of the battery capacity)
Red Bull Ring: ~8.6s braking, 3,010KJ possible recovery (just 3/4 of the battery capacity)
Monza: 9.25s braking, 3,237kJ (ie just over 3/4 of the battery capacity)
Silverstone: ~11s braking, 3,850kJ - still haven't filled the battery
Jeddah: ~11s braking, 3,850kJ - still haven't filled the battery
Singapore: ~17s, 5,950kJ (can fill the battery 1.5 times, but still not teh maximum 8.5MJ)
Monaco: ~19s, 6,650kJ (getting closer)
Baku: ~19s, 6,650kJ (7 of the braking events are classified as hard, 2 medium, 3 light)

These are data for the current cars.

The 2026 cars will have less downforce and grip so will brake for longer, but won't brake as hard. The amount of time that the maximum 350kW can be recovered may not be much greater, as they run out of grip.

The above times are for all braking events in a lap. That includes light brushes of the brakes in some corners.

Monaco, for example, has only 1 really heavy braking zone, out of the tunnel into the chicane. And that lasts for 2s.

These questions lead me to the conclusion that this will be a disaster of compromises that simply no-one will like/enjoy. If the racing is the same for everyone, then it will be a close-enough approximation to the concept of Formula 1, but it will be the most contrived set of contradictions that lead to nonsense power management interference in the race. F1 used to be a Man-vs-Nature sport. Now it is Man-vs-Man(rules), and I'm definitely a cynic from what I've seen so far.

[DenBommer]

I have to ask, if the limit of energy recovery per lap is 8.5MJ (for some tracks it will be reduced) and the energy recovery comes only from braking, where will teh additional recovery come from for tracks like:

Albert Park: ~8.5s braking, 2,975KJ possible recovery (ie not even 3/4 of the battery capacity)
Red Bull Ring: ~8.6s braking, 3,010KJ possible recovery (just 3/4 of the battery capacity)
Monza: 9.25s braking, 3,237kJ (ie just over 3/4 of the battery capacity)
Silverstone: ~11s braking, 3,850kJ - still haven't filled the battery
Jeddah: ~11s braking, 3,850kJ - still haven't filled the battery
Singapore: ~17s, 5,950kJ (can fill the battery 1.5 times, but still not teh maximum 8.5MJ)
Monaco: ~19s, 6,650kJ (getting closer)
Baku: ~19s, 6,650kJ (7 of the braking events are classified as hard, 2 medium, 3 light)

These are data for the current cars.

The 2026 cars will have less downforce and grip so will brake for longer, but won't brake as hard. The amount of time that the maximum 350kW can be recovered may not be much greater, as they run out of grip.

The above times are for all braking events in a lap. That includes light brushes of the brakes in some corners.

Monaco, for example, has only 1 really heavy braking zone, out of the tunnel into the chicane. And that lasts for 2s.

These questions lead me to the conclusion that this will be a disaster of compromises that simply no-one will like/enjoy. If the racing is the same for everyone, then it will be a close-enough approximation to the concept of Formula 1, but it will be the most contrived set of contradictions that lead to nonsense power management interference in the race. F1 used to be a Man-vs-Nature sport. Now it is Man-vs-Man(rules), and I'm definitely a cynic from what I've seen so far.

So what do you suggest?

[Zynerji]

I have to ask, if the limit of energy recovery per lap is 8.5MJ (for some tracks it will be reduced) and the energy recovery comes only from braking, where will teh additional recovery come from for tracks like:

Albert Park: ~8.5s braking, 2,975KJ possible recovery (ie not even 3/4 of the battery capacity)
Red Bull Ring: ~8.6s braking, 3,010KJ possible recovery (just 3/4 of the battery capacity)
Monza: 9.25s braking, 3,237kJ (ie just over 3/4 of the battery capacity)
Silverstone: ~11s braking, 3,850kJ - still haven't filled the battery
Jeddah: ~11s braking, 3,850kJ - still haven't filled the battery
Singapore: ~17s, 5,950kJ (can fill the battery 1.5 times, but still not teh maximum 8.5MJ)
Monaco: ~19s, 6,650kJ (getting closer)
Baku: ~19s, 6,650kJ (7 of the braking events are classified as hard, 2 medium, 3 light)

These are data for the current cars.

The 2026 cars will have less downforce and grip so will brake for longer, but won't brake as hard. The amount of time that the maximum 350kW can be recovered may not be much greater, as they run out of grip.

The above times are for all braking events in a lap. That includes light brushes of the brakes in some corners.

Monaco, for example, has only 1 really heavy braking zone, out of the tunnel into the chicane. And that lasts for 2s.

These questions lead me to the conclusion that this will be a disaster of compromises that simply no-one will like/enjoy. If the racing is the same for everyone, then it will be a close-enough approximation to the concept of Formula 1, but it will be the most contrived set of contradictions that lead to nonsense power management interference in the race. F1 used to be a Man-vs-Nature sport. Now it is Man-vs-Man(rules), and I'm definitely a cynic from what I've seen so far.

So what do you suggest?

Something small, compact, and lightweight enough to generate 600+ft/lb, and 1000hp. Inline 5 supercharged would sound like v10s, 2 stroke Inline 6 could rev to the moon. Modern TJI-like fuel efficiency with nothing in the exhaust tract, placed in a non-electrified, 600kg 2008-sized chassis would be my preference,

[saviour stivala]

The 2026 MGU-K will have its power output increased to 350 kw, this will allows it to recover more energy as well as provide a much larger power boost, roughly 470 hp. The 2026 'extra' energy recovery comes from doubling of energy recovery system power, which will be 8.5 mj per lap, and the removal of the MGU-H, leading to a much more potent MGU-K, while 8.5 mj is the target recovery, some teams may not achieve this on every lap and will need to manage energy strategically to make up the difference.

[diffuser]

The 2026 MGU-K will have its power output increased to 350 kw, this will allows it to recover more energy as well as provide a much larger power boost, roughly 470 hp. The 2026 'extra' energy recovery comes from doubling of energy recovery system power, which will be 8.5 mj per lap, and the removal of the MGU-H, leading to a much more potent MGU-K, while 8.5 mj is the target recovery, some teams may not achieve this on every lap and will need to manage energy strategically to make up the difference.

I don't think you're trying to say "The 2026 'extra' energy recovery comes from doubling of energy recovery system power, which will be 8.5 mj per lap, and the removal of the MGU-H," The removal of the MGU-H is hindering energy recovery. Yes, they are removing it but the removal is not helping the recovery.

What's Ironic to me is they're removing the MGU-H right at the time when many of the manufactures are actually using them on the street. The 2026 Porsche 911 turbo will run a MGU-H, they call it e-turbo but it does the exact same thing. It actually even has a small MGU-K, although the MGU-K design is different than what we see in F1. You can see how the MGU-H makes the power band almost flat. They said at 1500 rpm, they hit max boost 2 seconds before the 2025 Porsche 911 turbo. Naturally, the higher the rpm the smaller the boost lag difference. They're putting 700hp in a Porsche 911, that's a race car! All that extra power and the MGU-H, MGU-K and the lithium battery only way 85lbs more than the 2025 car.

[Badger]

I have to ask, if the limit of energy recovery per lap is 8.5MJ (for some tracks it will be reduced) and the energy recovery comes only from braking, where will teh additional recovery come from for tracks like:

Albert Park: ~8.5s braking, 2,975KJ possible recovery (ie not even 3/4 of the battery capacity)
Red Bull Ring: ~8.6s braking, 3,010KJ possible recovery (just 3/4 of the battery capacity)
Monza: 9.25s braking, 3,237kJ (ie just over 3/4 of the battery capacity)
Silverstone: ~11s braking, 3,850kJ - still haven't filled the battery
Jeddah: ~11s braking, 3,850kJ - still haven't filled the battery
Singapore: ~17s, 5,950kJ (can fill the battery 1.5 times, but still not teh maximum 8.5MJ)
Monaco: ~19s, 6,650kJ (getting closer)
Baku: ~19s, 6,650kJ (7 of the braking events are classified as hard, 2 medium, 3 light)

These are data for the current cars.

The 2026 cars will have less downforce and grip so will brake for longer, but won't brake as hard. The amount of time that the maximum 350kW can be recovered may not be much greater, as they run out of grip.

The above times are for all braking events in a lap. That includes light brushes of the brakes in some corners.

Monaco, for example, has only 1 really heavy braking zone, out of the tunnel into the chicane. And that lasts for 2s.

These values have been known for over 3 years and the calculation for this is quite simple as you've demonstrated. I can't believe people are only realising now

To answer your question, how will they solve this? They won't "solve" it, they'll just create a different problem. That is, to increase the amount of harvest time they'll be forced to cut power to the wheels towards the end of straights, and also lengthen the braking zones. At the cost of speed and performance (the new problem).

This is roughly how I imagine it will work in race trim. You're going along the straight at 420 kW or whatever the ICE generates. Several hundred meters before the end of the straight (exact number will vary depending on the track) the MGU-K will start harvesting which will start cutting power to the wheels gradually. See the diagram that gruntguru posted to see the kW numbers the regulations allow for here. After a few seconds of harvesting this way (car will decelerate slowly) you'll hit the active braking zone. This will be a longer braking zone than what we have currently (especially in race trim), the cars will try to harvest as much kinetic energy as possible on the rear axle by braking as little as possible with the front. It's basically going to be a massive brake migration from rear to front as the car slows down from high speed, initally almost no front brakes, and then gradually the front takes over as normal when the car slows down for the final apex.

You'll also have mid corner harvesting for when you are not demanding full power to the wheels, you can send the rest to the battery.

So they'll find the harvest time, it will just come at the cost of performance, and probably spectacle as we no longer get those high G braking events.

[saviour stivala]

MGU-K energy recovery during cornering in 2026 against an increased ICE revs will require the driver to also lightly brake, in short the brake pedal will have to be used. The increased ICE revs will be allowed to happen even if driver lifts off throttle by special maps.

[Tommy Cookers]

in the 2014-2025 rules the 100 kg/hr fuel rate and 100 kg fuel consumption twins were sacred
then to help some teams give a better impression the fuel consumption limit was slipped to 105 kg
then to help it was slipped to 110 kg (when the fuel blend was dumbed-down)

for 2026 there seems to be no consumption limit ?? - only a fuel (heat) rate limit
again to help the least competitive teams give a better impression eg by having sufficient electrical energy