2025/2026 Hybrid Powerunit speculation

[Zynerji]

Here are some nice quotes from the Reddit user GaryGiesel, a verified F1 vehicle dynamicist, about what might happen in 2026. Found in the comments in here: https://www.reddit.com/r/formula1/comme ... _terrible/

This one with respect to the claim on a YouTube video that turbo lag returns:

I know better than the F1 YouTube channel, given I have actual experience of engineering F1 hybrid power units

A lack of authority from the MGUK is very unlikely to be a problem; it’s more laptime efficient to keep the K not delivering torque until the point where the ICE is delivering full power (in fact, we’re likely to end up running the MGUK in generator mode in part-throttle conditions - this is something we do with the current engines, effectively converting fuel directly into electrical energy).

I can promise you that we as engineers will not accept poor drivability from turbo lag. Where there’s performance to be found we will find it

Another one:

We already use the K to fill in torque holes with the current PUs. Reducing turbo lag isn’t the main purpose of the H; it’s there to recover energy on full throttle.

Yes there will be much more clipping with the new regs. It’ll be similar to the last generation of LMP1 cars; massive power out of the corners, but then relatively low top speeds because you don’t have the energy available to sustain. I don’t see it being the death of good racing that so many people here seem to be expecting though, because any sort of overtake button is going to be vastly more powerful. I think we’ll see cars doing big deployments to pass , and then really struggling to keep ahead as they desperately try to recover that extra energy spend. Could be very interesting!

Ugh. A bunch of 50kph to 150kph drag races...

[Rodak]

4. Synth fuel can be straight ethanol or nitro-methane. I prefer the nitro. I don't care where it's made.

Interesting topic and some good thoughtful input here; I hope the FIA is as diligent. As to using nitro-methane, you wouldn't get very far on 100 kg as the air/fuel ratio is about 1.7:1 ....

The 2026 engine formula certainly wouldn't work very well at Indy.....

[wuzak]

I have previously talked about deployment on the straights, but there will be corners where more power than the ICE alone can deliver, so deployment will be required.

[Cs98]

Here are some nice quotes from the Reddit user GaryGiesel, a verified F1 vehicle dynamicist, about what might happen in 2026. Found in the comments in here: https://www.reddit.com/r/formula1/comme ... _terrible/

This one with respect to the claim on a YouTube video that turbo lag returns:

I know better than the F1 YouTube channel, given I have actual experience of engineering F1 hybrid power units

A lack of authority from the MGUK is very unlikely to be a problem; it’s more laptime efficient to keep the K not delivering torque until the point where the ICE is delivering full power (in fact, we’re likely to end up running the MGUK in generator mode in part-throttle conditions - this is something we do with the current engines, effectively converting fuel directly into electrical energy).

I can promise you that we as engineers will not accept poor drivability from turbo lag. Where there’s performance to be found we will find it

Another one:

We already use the K to fill in torque holes with the current PUs. Reducing turbo lag isn’t the main purpose of the H; it’s there to recover energy on full throttle.

Yes there will be much more clipping with the new regs. It’ll be similar to the last generation of LMP1 cars; massive power out of the corners, but then relatively low top speeds because you don’t have the energy available to sustain. I don’t see it being the death of good racing that so many people here seem to be expecting though, because any sort of overtake button is going to be vastly more powerful. I think we’ll see cars doing big deployments to pass , and then really struggling to keep ahead as they desperately try to recover that extra energy spend. Could be very interesting!

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. You'll also charge a lot less. Seems like a much more useful tool when you have an 800+ HP ICE and a sub 200 HP MGU-K.

b, His reference to LMP1. It's a closed wheel low drag series, F1 is not (even with fancy active aero). The Toyota had dual axle regen, the Porsche had front axle regen and exhaust gas regen. F1 will be stuck with only rear axle regen and a 50/50 power split. Seems to me these regulations were designed in the image of the Toyota GR050, except with more drag, less overall power and no front axle regen, which kind of defeats the entire concept.

[gruntguru]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

[Tommy Cookers]

... the new formula will be championed again for achieving so much with so little fuel burned like the one before it.

it will achieve less
because the prime mover (the ICE) will be less efficient (2026 c.47% vs 2024 c.50%) as exhaust recovery is now banned

the increased KE recovery from the 350 kW MGU-K is recovery from an arbitrary load system (car in an F1 motor race)
if the load system was different eg race on the circle on Bonneville salt flats there would be zero recovery

recovery from a load system doesn't increase the prime mover efficiency

the 2026 car is like a dog whose tail is as big as the rest of the dog
yes it's interesting

[wuzak]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

Given that most F1 tracks have full throttle of between 60% to 80%, how much time at part throttle that has low enough power that the MGUK could recover a meaningful amount of energy?

I'm sure there will be a lot of part throttle corners where the power required is greater than the ICE can deliver alone.

[Cs98]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

We're not talking about braking, we're talking partial throttle. Getting perfect regen under braking is a pre-requisite to make this even remotely work, and it's still not close to enough, which is why he made the partial throttle argument.

I don't think you will find much regen in partial throttle zones for the reasons I outlined. You need 3x more regen and your combustion engine is 40% less powerful. F1 tracks are like 70% full throttle, 10% and a bit braking. And that's with 800-1000HP engines. Imagine you have 500HP, how much partial throttle do you really think we're gonna have? The cars would have to be ridiculously slow for there to be a lot of partial throttle with a 500HP ICE. And for the very limited time you have partial throttle you obviously won't get the full 350kW, but a limited amount based on the power demand at the rear wheels.

[AR3-GP]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

These cars are going to sound like they have CVT transmissions....

What with the engine load no longer being in-sync with the driver inputs...

[Hoffman900]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

We're not talking about braking, we're talking partial throttle. Getting perfect regen under braking is a pre-requisite to make this even remotely work, and it's still not close to enough, which is why he made the partial throttle argument.

I don't think you will find much regen in partial throttle zones for the reasons I outlined. You need 3x more regen and your combustion engine is 40% less powerful. F1 tracks are like 70% full throttle, 10% and a bit braking. And that's with 800-1000HP engines. Imagine you have 500HP, how much partial throttle do you really think we're gonna have? The cars would have to be ridiculously slow for there to be a lot of partial throttle with a 500HP ICE. And for the very limited time you have partial throttle you obviously won't get the full 350kW, but a limited amount based on the power demand at the rear wheels.

No one knows what the aero is going to be.

Horsepower in a vehicle is pointless to discuss without knowing how much horsepower is consumed by aero drag and friction (tires, bearings, etc).

I did the very rough math once for a 2013 era RB car that was published, and it was near 750hp consumed to go 190mph. The current cars are likely draggier. The new rule set the cars are supposed to be much less draggy in a straight line with their active aero. The whole engine concept is contingent on that reducing drag.

[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.

[Cs98]

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

We're not talking about braking, we're talking partial throttle. Getting perfect regen under braking is a pre-requisite to make this even remotely work, and it's still not close to enough, which is why he made the partial throttle argument.

I don't think you will find much regen in partial throttle zones for the reasons I outlined. You need 3x more regen and your combustion engine is 40% less powerful. F1 tracks are like 70% full throttle, 10% and a bit braking. And that's with 800-1000HP engines. Imagine you have 500HP, how much partial throttle do you really think we're gonna have? The cars would have to be ridiculously slow for there to be a lot of partial throttle with a 500HP ICE. And for the very limited time you have partial throttle you obviously won't get the full 350kW, but a limited amount based on the power demand at the rear wheels.

No one knows what the aero is going to be.

Horsepower in a vehicle is pointless to discuss without knowing how much horsepower is consumed by aero drag and friction (tires, bearings, etc).

I did the math once for a 2013 era RB car that was published, and it was near 750hp consumed to go 190mph. The current cars are likely draggier. The new rule set the cars are supposed to be much less draggy in a straight line with their active aero. The whole engine concept is contingent on that reducing drag.

This is an open wheel series, those tyres are probably the draggiest thing on the entire car and that's not going to change. That's one of the reasons why LMP1 is not a good comparison for 2026.

You also forget weight, seems like that isn't going down either. In 2013 cars weighed what? 600 kgs? 650? Power/weight is more important for the sense of speed and acceleration than drag.

So my concern isn't just top speed, it's overall speed.

[Hoffman900]

We're not talking about braking, we're talking partial throttle. Getting perfect regen under braking is a pre-requisite to make this even remotely work, and it's still not close to enough, which is why he made the partial throttle argument.

I don't think you will find much regen in partial throttle zones for the reasons I outlined. You need 3x more regen and your combustion engine is 40% less powerful. F1 tracks are like 70% full throttle, 10% and a bit braking. And that's with 800-1000HP engines. Imagine you have 500HP, how much partial throttle do you really think we're gonna have? The cars would have to be ridiculously slow for there to be a lot of partial throttle with a 500HP ICE. And for the very limited time you have partial throttle you obviously won't get the full 350kW, but a limited amount based on the power demand at the rear wheels.

No one knows what the aero is going to be.

Horsepower in a vehicle is pointless to discuss without knowing how much horsepower is consumed by aero drag and friction (tires, bearings, etc).

I did the math once for a 2013 era RB car that was published, and it was near 750hp consumed to go 190mph. The current cars are likely draggier. The new rule set the cars are supposed to be much less draggy in a straight line with their active aero. The whole engine concept is contingent on that reducing drag.

This is an open wheel series, those tyres are probably the draggiest thing on the entire car and that's not going to change. That's one of the reasons why LMP1 is not a good comparison for 2026.

You also forget weight, seems like that isn't going down either. In 2013 cars weighed what? 600 kgs? 650? Power/weight is more important for the sense of speed and acceleration than drag.

So my concern isn't just top speed, it's overall speed.

Drag consumes the most power on a straightaway and power needed to increase is the cube of speed. The numbers I used, a change of 0.15 Cd was near 20hp at 190mph.

Discussing horsepower and its effects on the car is pointless without knowing power consumed and masses involved.

This is also why comparing PU performance from traps speeds is a pointless exercise when they start getting within a few percent of each other. Also pointless because if you can make 50hp more than a competitor, you just add 50hp more of downforce (expressed in drag). 50hp might get you 2-3mph at 190mph or it can get you half a second over a lap because you can run that much more downforce.

[Cs98]

No one knows what the aero is going to be.

Horsepower in a vehicle is pointless to discuss without knowing how much horsepower is consumed by aero drag and friction (tires, bearings, etc).

I did the math once for a 2013 era RB car that was published, and it was near 750hp consumed to go 190mph. The current cars are likely draggier. The new rule set the cars are supposed to be much less draggy in a straight line with their active aero. The whole engine concept is contingent on that reducing drag.

This is an open wheel series, those tyres are probably the draggiest thing on the entire car and that's not going to change. That's one of the reasons why LMP1 is not a good comparison for 2026.

You also forget weight, seems like that isn't going down either. In 2013 cars weighed what? 600 kgs? 650? Power/weight is more important for the sense of speed and acceleration than drag.

So my concern isn't just top speed, it's overall speed.

Drag consumes the most power on a straightaway and power needed goes up with the cube of speed. The numbers I used, a change of 0.15 Cd was near 20hp at 190mph.

Well, we're losing 300-500HP at top speed, so unless you plan on shedding so much drag it becomes a low drag roadcar, I'm not holding out hope. And like I said, even with active aero, this is an open-wheel formula car, it's always going to be relatively draggy.

Overall speed is also more important than top speed, which is why weight and big HP matter. Acceleration is king.

[NL_Fer]

So even if the ice would be allowed to deliver full power under braking, to let the MGU-K generate, there isn’t enough fuel, because then the ICE would be at full power a whole lap. Never enough for more than 20-30% full throttle with ERS deployment.

It really means downshifting down the straight, or the drag must become 0 on the straight.