2025/2026 Hybrid Powerunit speculation

[AR3-GP]

The part missing in this conversation is this applies to the current cars which have a Cd approaching 1.0 Cd, this is substantially worst than most pickup trucks.

Part of the new rule set is to use active aero to reduce drag on the straights. This is the part the entire PU / hybrid rule set is banking on to make work, otherwise you end up in the situation Horner is describing. The aero / chassis rules haven’r been finalized and the teams wouldn’t be able to simulate those.

How will DRS work if cars are already trimming out on the straights? How would overtaking work?

Active aero is interesting enough for a qualy lap, but doesn't it have drawbacks for actual racing? So you can create all the dirty air you want in the corners, and then cloak your Cd on the straights.

Would they be relying on a push to pass system in that case?

That is the second part of the complaint made by Verstappen and Horner.

Read Max’s point here: https://us.motorsport.com/f1/news/f1s-2 ... /10490913/

He explicitly calls out this part of the 2026+ rules.

I personally like push to pass like used in DTM and Indy Car. Let the driver’s decide when to use it and takes the whole “did we get the DRS zones” right out of the equation, and if you use it up, you use it up.

I think that a push to pass system, if it's limited, could still create the same problems that we had before DRS. You have scenarios where both drivers use it at the same time and nothing happens, or you have a scenario where most people use it up, and then there's no more overtaking towards the end of the race. DTM and Indycar do not have active aero so they still benefit from slip streaming (although I think DTM had DRS at one point?, I don't know if you are talking about the GT3 cars or the previous gen).

[Hoffman900]

How will DRS work if cars are already trimming out on the straights? How would overtaking work?

Active aero is interesting enough for a qualy lap, but doesn't it have drawbacks for actual racing? So you can create all the dirty air you want in the corners, and then cloak your Cd on the straights.

Would they be relying on a push to pass system in that case?

That is the second part of the complaint made by Verstappen and Horner.

Read Max’s point here: https://us.motorsport.com/f1/news/f1s-2 ... /10490913/

He explicitly calls out this part of the 2026+ rules.

I personally like push to pass like used in DTM and Indy Car. Let the driver’s decide when to use it and takes the whole “did we get the DRS zones” right out of the equation, and if you use it up, you use it up.

I think that a push to pass system, if it's limited, could still create the same problems that we had before DRS. You have scenarios where both drivers use it at the same time and nothing happens, or you have a scenario where most people use it up, and then there's no more overtaking towards the end of the race. DTM and Indycar do not have active aero so they still benefit from slip streaming (although I think DTM had DRS at one point?, I don't know if you are talking about the GT3 cars or the previous gen).

Yes and no. The nice part about push to pass is that everyone has the same advantage. DRS, some teams are better able to utilize it than others, and it just so happens those teams happen to be the front running teams.

There is more strategy involved with PtP.

That said, I don’t see it happening, because with the hybrid rule set they just might use the extra power to charge as opposed to going faster, and it just complicates everything. For PtP you also need more fuel as that is how you do it, which is counter to the new rule set.

DTM is a fuel flow limited rule set and PtP increases the flow rate. The new 2026 F1 rule set is going the opposite way, so it won’t happen.

[vorticism]

Passing is a feature of horse and automobile racing. Over the decades the men of F1's engineering history developed the cars into four wheeled aircraft. Passing is not a feature of aircraft racing, which is largely time trial. That's why there's no such thing as a 'boring' F1 race, which are aero time trial races with vestigial auto racing features.

Hoffman900, Tommy and the others were talking about traction and braking limits on the rear axles wrt harvesting; he and they are not wrong about this. It's not an aero drag question (that specific topic). Yes, the comments by Verstappen and Horner were probably about net drag and ES charge depletion effects requiring downshifting to get the cars down Monza straights.

[Hoffman900]

Passing is a feature of horse and automobile racing. Over the decades the men of F1's engineering history developed the cars into four wheeled aircraft. Passing is not a feature of aircraft racing, which is largely time trial. That's why there's no such thing as a 'boring' F1 race, which are aero time trial races with vestigial auto racing features.

Hoffman900, Tommy and the others were talking about traction and braking limits on the rear axles wrt harvesting; he and they are not wrong about this. It's not an aero drag question. I'd ask if you're new here, but you're not.

I understand, but downforce is going to do more rear wheel tractive force than tire size. Also, more rear tire grip, will reduce braking zones, so you’re not really able to put more into it as much as you think.

This is why MotoGP was stuck at less than 2g’s forever in braking force regardless of tire size, until the aero wars of today which allows them to put more rear force on the bike.

The 2026 rules are as I say and the reasons for them. Simple as that, the concept is already written down and agreed upon. No use discussing anything else as it’s all for naught; 4wd, different tire sizes, etc. It’s all deviating from the topic.

[Big Tea]

That is the second part of the complaint made by Verstappen and Horner.

Read Max’s point here: https://us.motorsport.com/f1/news/f1s-2 ... /10490913/

He explicitly calls out this part of the 2026+ rules.

I personally like push to pass like used in DTM and Indy Car. Let the driver’s decide when to use it and takes the whole “did we get the DRS zones” right out of the equation, and if you use it up, you use it up.

I think that a push to pass system, if it's limited, could still create the same problems that we had before DRS. You have scenarios where both drivers use it at the same time and nothing happens, or you have a scenario where most people use it up, and then there's no more overtaking towards the end of the race. DTM and Indycar do not have active aero so they still benefit from slip streaming (although I think DTM had DRS at one point?, I don't know if you are talking about the GT3 cars or the previous gen).

Yes and no. The nice part about push to pass is that everyone has the same advantage. DRS, some teams are better able to utilize it than others, and it just so happens those teams happen to be the front running teams.

There is more strategy involved with PtP.

That said, I don’t see it happening, because with the hybrid rule set they just might use the extra power to charge as opposed to going faster, and it just complicates everything. For PtP you also need more fuel as that is how you do it, which is counter to the new rule set.

DTM is a fuel flow limited rule set and PtP increases the flow rate. The new 2026 F1 rule set is going the opposite way, so it won’t happen.

I would also mean we would not have the same cars holding up a 'train' of other cars all with the same advantage.
Once the advantage is used, it is back to driver skill or plain having a better car.

[Zynerji]

What is the thought about a non hybrid concept? Could the teams even make a race distance with 100kilo of fuel? Does moving to a more bespoke fuel help? Is the Turbo necessary for the lean-burn/tji concepts? Could it be simplified to a 2.2ishL v6 single turbo on synth fuel?

I feel that the simpler the concept, the quicker the convergence, the better the racing.

[Hoffman900]

What is the thought about a non hybrid concept? Could the teams even make a race distance with 100kilo of fuel? Is the Turbo necessary for the lean-burn/tji concepts? Could it be simplified to a 2.2ishL v6 single turbo on synth fuel?

I feel that the simpler the concept, the quicker the convergence, the better the racing.

1) they could but would have to sacrifice downforce (drag) and lap time. There are already fuel mileage competitions elsewhere and they are not exciting at all.

2) TJI no, but the TJI / HCCI hybrid combustion concepts, yes. They need a lot of excess air to work as does the Miller Cycle concept. A lean burn naturally aspirated engine would be the most anemic thing and still not be as efficient.

3) You can simplify anything. That’s what NASCAR and Indy Car attempt to do. That will not excite the manufacturers. They are looking at downsized, high specific output engines, to power a hybrid system. No different than has been used on trains, ships, and other heavy machinery for well over half a century.

Why would you want to add a L of displacement? That requires a much bigger PU. Single turbo is already a thing and more efficient, especially the dual feed single turbos.

I don’t get the synth fuel thing. You know where synth fuel is made? In a refinery and has a bunch of hazardous constituents as well. It’s just environmental whack a mole.

Lastly, none of this matters. The rules are mostly done and dusted.

[Zynerji]

What is the thought about a non hybrid concept? Could the teams even make a race distance with 100kilo of fuel? Is the Turbo necessary for the lean-burn/tji concepts? Could it be simplified to a 2.2ishL v6 single turbo on synth fuel?

I feel that the simpler the concept, the quicker the convergence, the better the racing.

1) they could but would have to sacrifice downforce (drag) and lap time. There are already fuel mileage competitions elsewhere and they are not exciting at all.

2) TJI no, but the TJI / HCCI hybrid combustion concepts, yes. They need a lot of excess air to work as does the Miller Cycle concept. A lean burn naturally aspirated engine would be the most anemic thing and still not be as efficient.

3) You can simplify anything. That’s what NASCAR and Indy Car attempt to do. That will not excite the manufacturers. They are looking at downsized, high specific output engines, to power a hybrid system. No different than has been used on trains, ships, and other heavy machinery for well over half a century.

Why would you want to add a L of displacement? That requires a much bigger PU. Single turbo is already a thing and more efficient, especially the dual feed single turbos.

I don’t get the synth fuel thing. You know where synth fuel is made? In a refinery and has a bunch of hazardous constituents as well. It’s just environmental whack a mole.

Lastly, none of this matters. The rules are mostly done and dusted.

To answer:

1. Reducing the size of the cars, and un-restricting the front wing/ floor/diffusor would still get you there.Dynamic vector differentials would also add skill and help the cornering.

2. Thanks. I like the turbo-leanburn-HCCI concept.Its literally more bang for the buck!

3. Adding .6L of Displacement can be done with stroke alone, I imagine. Its like a half-inch difference. A 2.2 just gives more lean-burn/output torque opportunities that may prevent an RPM war. Keep the 8 speed for this purpose.

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

Lastly. I'll be a fan when the regulations after this come about. Even if this cycle is still effected by the psyop, the next one doesn't need to be.

[Hoffman900]

[quote=Zynerji post_id=1144257 time=1688575227 user_id=35056]
[quote=Hoffman900 post_id=1144235 time=1688571456 user_id=41250]
[quote=Zynerji post_id=1144231 time=1688571000 user_id=35056]
What is the thought about a non hybrid concept? Could the teams even make a race distance with 100kilo of fuel? Is the Turbo necessary for the lean-burn/tji concepts? Could it be simplified to a 2.2ishL v6 single turbo on synth fuel?

I feel that the simpler the concept, the quicker the convergence, the better the racing.
[/quote]

1) they could but would have to sacrifice downforce (drag) and lap time. There are already fuel mileage competitions elsewhere and they are not exciting at all.

2) TJI no, but the TJI / HCCI hybrid combustion concepts, yes. They need a lot of excess air to work as does the Miller Cycle concept. A lean burn naturally aspirated engine would be the most anemic thing and still not be as efficient.

3) You can simplify anything. That’s what NASCAR and Indy Car attempt to do. That will not excite the manufacturers. They are looking at downsized, high specific output engines, to power a hybrid system. No different than has been used on trains, ships, and other heavy machinery for well over half a century.

Why would you want to add a L of displacement? That requires a much bigger PU. Single turbo is already a thing and more efficient, especially the dual feed single turbos.

I don’t get the synth fuel thing. You know where synth fuel is made? In a refinery and has a bunch of hazardous constituents as well. It’s just environmental whack a mole.

Lastly, none of this matters. The rules are mostly done and dusted.
[/quote]

To answer:

1. Reducing the size of the cars, and un-restricting the front wing/ floor/diffusor would still get you there.

2. Thanks. I like the turbo-leanburn-HCCI concept.Its [i]literally[/i] more bang for the buck!

3. Adding .6L of Displacement can be done with stroke alone, I imagine. Its like a half-inch difference. A 2.2 just gives more lean-burn/output torque opportunities that may prevent an RPM war. Keep the 8 speed for this purpose.

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

Not necessarily. You can have less frontal area and still have more drag. A longer / bigger car may treat the air better. The concept of aero downforce is just going to have an opposite effect on what you want to do to reduce drag.

Adding more stroke raises the deck height, now you have to move the plenum out too to keep your intake runners where you need them for mass flow and cylinder motion, and now the exhaust is pushed out as well. Engines exist in cars, not just dynos, and their physical dimensions matter. There is no rpm war, they can’t use all the rpm they have now because the combustion won’t support it. The engines are constant boost, varying lambda, the higher rpm they go the more diluted the charge, until they get to a point where the piston speed outruns the combustion process.

Wasting potable water supplies and increasing fertilizer runoff is not a solution.

[Hoffman900]

[quote=Zynerji post_id=1144257 time=1688575227 user_id=35056]
[quote=Hoffman900 post_id=1144235 time=1688571456 user_id=41250]
[quote=Zynerji post_id=1144231 time=1688571000 user_id=35056]
What is the thought about a non hybrid concept? Could the teams even make a race distance with 100kilo of fuel? Is the Turbo necessary for the lean-burn/tji concepts? Could it be simplified to a 2.2ishL v6 single turbo on synth fuel?

I feel that the simpler the concept, the quicker the convergence, the better the racing.
[/quote]

1) they could but would have to sacrifice downforce (drag) and lap time. There are already fuel mileage competitions elsewhere and they are not exciting at all.

2) TJI no, but the TJI / HCCI hybrid combustion concepts, yes. They need a lot of excess air to work as does the Miller Cycle concept. A lean burn naturally aspirated engine would be the most anemic thing and still not be as efficient.

3) You can simplify anything. That’s what NASCAR and Indy Car attempt to do. That will not excite the manufacturers. They are looking at downsized, high specific output engines, to power a hybrid system. No different than has been used on trains, ships, and other heavy machinery for well over half a century.

Why would you want to add a L of displacement? That requires a much bigger PU. Single turbo is already a thing and more efficient, especially the dual feed single turbos.

I don’t get the synth fuel thing. You know where synth fuel is made? In a refinery and has a bunch of hazardous constituents as well. It’s just environmental whack a mole.

Lastly, none of this matters. The rules are mostly done and dusted.
[/quote]

To answer:

1. Reducing the size of the cars, and un-restricting the front wing/ floor/diffusor would still get you there.

2. Thanks. I like the turbo-leanburn-HCCI concept.Its [i]literally[/i] more bang for the buck!

3. Adding .6L of Displacement can be done with stroke alone, I imagine. Its like a half-inch difference. A 2.2 just gives more lean-burn/output torque opportunities that may prevent an RPM war. Keep the 8 speed for this purpose.

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

Not necessarily. You can have less frontal area and still have more drag. A longer / bigger car may treat the air better. The concept of aero downforce is just going to have an opposite effect on what you want to do to reduce drag.

Adding more stroke raises the deck height, now you have to move the plenum out too to keep your intake runners where you need them for mass flow and cylinder motion, and now the exhaust is pushed out as well. Engines exist in cars, not just dynos, and their physical dimensions matter. More stoke also needs a larger diameter crankcase for the throws and counterweights. There is no rpm war, they can’t use all the rpm they have now because the combustion won’t support it. The engines are constant boost, varying lambda, the higher rpm they go the more diluted the charge, until they get to a point where the piston speed outruns the combustion process.

Wasting potable water supplies and increasing fertilizer runoff is not a solution.

[Zynerji]

Nah. A deeper oil pan, maybe. No need for deck height.

And we could literally see combustion based upon RDE igniter designs. No need for a flame front when the compression wave ignites everything instantly.

They would run more RPM if they could feed it with fuel. Increasing explosions per second is a thing that makes more power, I believe.

Don't mind the fertilizer and potable water. There is plenty available for a single race series. I'm also a fan of hot-swappable CNG pods. Bulk refueling without a liquid connection outside the car.

[Tommy Cookers]

Help what? Tommy is wrong and I have no idea what he is talking about.
The rules are as I said, less IC power and more EC power, and to keep them from running out of charge, they’re going to allow active aero to reduce drag.

as I said ....
if the DF on braking is conventional the 350 kW MG will recover for less % of the braking time than the 120 kW MG does

if the DF on braking is less than conventional the braking time and braking distance will increase ....
but ok yes that will increase the recovery energy

[Hoffman900]

Nah. A deeper oil pan, maybe. No need for deck height.

And we could literally see combustion based upon RDE igniter designs. No need for a flame front when the compression wave ignites everything instantly.

They would run more RPM if they could feed it with fuel. Increasing explosions per second is a thing that makes more power, I believe.

Don't mind the fertilizer and potable water. There is plenty available for a single race series. I'm also a fan of hot-swappable CNG pods. Bulk refueling without a liquid connection outside the car.

If you increase the stroke you have more swept volume, and thus the deck height has to increase. A piston can’t go through the head. I think like you often do, you’re just throwing word salads out there without understanding why or what you’re proposing.

They can’t feed it more fuel because they are fuel limited per rules. So either they run out at the end or they just simply exceed the flow rate.

[saviour stivala]

Sitting back and reflecting in total amazement how all those technical brains directly involved voted in all this doom and gloom into formula one of the future. But then somebody passing by reminded me that pre and past 2014 is repeating itself and chances are that the new formula will be championed again for achieving so much with so little fuel burned like the one before it.

[karana]

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!