2026 Hybrid Powerunits

[dialtone]

.. there is a limit of energy usage per hour. For a typical race that translates to around 70 kg of fuel and that is what Scarbs meant.

it doesn't translate to around 70 kg per race
it translates to around 100 kg per race
the limit to what could be used

the heat rate per hour has been cut by 30% but the kg per heat rate has been raised eg by 15%

Could be fun if they ditch the energy max flow.

Some crazy last stints vs. fuel saving through the full race.

Nevertheless, as always, simulations should point to an optimum fuel load.

The right approach should have been to regulate the max fuel load, not the fuel flow, let the driver and team handle the race strategy and allow them to run out of fuel at the end like the good old times.

[BassVirolla]

it doesn't translate to around 70 kg per race
it translates to around 100 kg per race
the limit to what could be used

the heat rate per hour has been cut by 30% but the kg per heat rate has been raised eg by 15%

Could be fun if they ditch the energy max flow.

Some crazy last stints vs. fuel saving through the full race.

Nevertheless, as always, simulations should point to an optimum fuel load.

The right approach should have been to regulate the max fuel load, not the fuel flow, let the driver and team handle the race strategy and allow them to run out of fuel at the end like the good old times.

In my opinion, none of both. Let each team get their own compromises. While we still have racing without refueling, give some strategic leeway at the fuel management.

Also we were robbed of the tire management strategy because of Pirelli... Always is faster going slower.

[wuzak]

Depending on track, and the availability of braking energy recovery, the amount of fuel required for fuel burning is around 10kg - 12kg.

Say that the energy density is 41MJ/kg, the ICE efficiency is 48%, and the extra energy required by fuel burning is 4MJ (ie 4.5MJ from braking/lift-and-coast).

Fuel energy required is 4MJ/48% = 8.3MJ.
8.3MJ/(41MJ/kg) = 0.2033kg/lap.

Most races fall in the 50-60 lap range.

Extra fuel:
50 * 0.2033 = 10.2kg
60 * 0.2033 = 12.2kg

There may be a balance point where recovering extra energy per lap (up to the maximum) costs more in lap time than the extra energy deployment gains.

With the slightly lower minimum weight, I expect that the lap times will be more sensative to extra weight than in the last rule set.

The 2025 rules did not have a race fuel maximum usage. And the 2026 rules also don't have this limit.

I'd suggest that 85-90kg is more likely than 100kg.

This is based on 3000MJ for the race (2014-2016 rules had 100kg/h and 100kg race fuel), fuel energy density near the maximum (41MJ/kg) and the above calculation for extra fuel required.

3000MJ/(41MJ/kg) = 73.2kg.

73.2kg + 10.2kg = 83.4kg
73.2kg + 12.2kg = 85.4kg

[FW17]

Fuel energy required is 4MJ/48% = 8.3MJ.
8.3MJ/(41MJ/kg) = 0.2033kg/lap.

Most races fall in the 50-60 lap range.

Extra fuel:
50 * 0.2033 = 10.2kg
60 * 0.2033 = 12.2kg

That is 14 sec for a 100 sec lap (50 lap race), 73 kg fuel, 1.4 kg per lap
and 13 sec for a 80 sec lap (60 lap race) 73 kg fuel, 1.2 kg per lap

Even a third of it seems excessive lift and coast for each lap

[wuzak]

Fuel energy required is 4MJ/48% = 8.3MJ.
8.3MJ/(41MJ/kg) = 0.2033kg/lap.

Most races fall in the 50-60 lap range.

Extra fuel:
50 * 0.2033 = 10.2kg
60 * 0.2033 = 12.2kg

That is 14 sec for a 100 sec lap (50 lap race), 73 kg fuel, 1.4 kg per lap
and 13 sec for a 80 sec lap (60 lap race) 73 kg fuel, 1.2 kg per lap

Even a third of it seems excessive lift and coast for each lap

It does.

But it also includes part throttle and full throttle recovery.

Also, lift-and-coast isn't burning fuel to generate power.

4MJ is, likely, at the higher end of energy required for fuel burning.

[Tommy Cookers]

... Fuel energy required is 3000MJ/(41MJ/kg) = 73.2kg.
73.2kg + 12.2kg = 85.4kg

yes ....
and so with the 38 MJ/kg option total fuel consumption per 60 laps is 93.4 kg

and ....
if that fuel's explosive range was higher ie a leaner AFR (relative to stoichiometric) and higher TE was so enabled ....
maybe 1% or 2% more power & energy .....

[Schumix]

https://autoracer.it...rezza-alla-fia/



A source reveals that increasing the compression ratio is considerable: “It can reach +6/7% of the ICE power, +3/4% overall PU.
“We all have the skills to do it, it's not allowed. The FIA must be able to check it almost in real time” Binotto.

As already revealed by AutoRacer , Audi is the team pushing hardest to check Brixworth's engine , and Mattia Binotto made no secret of this during his presentation: "If what they're talking about were actually true, the performance gap would be significant ," he admitted bluntly. Significant is exactly the right word, a term also used by another engine specialist well before Binotto spoke in the past few hours. As we've already reported , moving from a compression ratio of 16 to 18 would guarantee an advantage of more than 40 hp, with further benefits for the Power Unit in terms of efficiency, energy recovery, and other values ​​that explain Binotto's strong concern. Audi Technical Director James Key also briefly commented on the matter. "I think it would be like bypassing the purpose of the regulations, which are somehow intended to control this area. We trust the FIA ​​because no one wants to go through a season where someone has a significant advantage and there's no solution, since the Power Unit is homologated. We hope the FIA ​​makes the right decision." With the FIA ​​likely to fail to intervene very soon, the teams would have no choice but to protest in Australia, moving from words to action. However, it's not that easy: "You can protest if you know what you're protesting against," Mattia Binotto stated.

What Mattia Binotto is revealing is deplorable for the sport. Could someone explain why Ferrari's PU wasn't compliant with the regulations in 2019, forcing them to restrict their engine, and why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? If i remember correctly, in 2019, the fuel flow measurement of Ferrari's PU was compliant at the measurement intervals, but not between two measurement points. In other words, Ferrari's PU in 2019 complied with the regulations (measured flow) but not with the spirit of the regulations. I'm just trying to understand this situation that distorts the competition.

[diffuser]

it doesn't translate to around 70 kg per race
it translates to around 100 kg per race
the limit to what could be used

the heat rate per hour has been cut by 30% but the kg per heat rate has been raised eg by 15%

Could be fun if they ditch the energy max flow.

Some crazy last stints vs. fuel saving through the full race.

Nevertheless, as always, simulations should point to an optimum fuel load.

The right approach should have been to regulate the max fuel load, not the fuel flow, let the driver and team handle the race strategy and allow them to run out of fuel at the end like the good old times.

Weight has forever been the enemy of lap time. So when you suggest a race fuel qty limit, that's already been built into F1 for years.
The fuel calculation includes the density of your fuel, the more energy you're fuel has, less flow you're allowed ...

Fuel Energy Flow ≤ 3000 MJ per hour
Allowed density range: 720–785 kg per cubic meter

To convert that to fuel mass flow:
    m˙=LHV (MJ/kg)
        3000 MJ/h

The FIA fuel LHV window is:
- 38.0–41.0 MJ/kg.

LHV value	                Mass flow limit (kg/h)
38 MJ/kg (lower energy per kg)	3000 / 38 ≈ 79 kg/h
41 MJ/kg (higher energy per kg)	3000 / 41 ≈ 73 kg/h

So the allowed mass flow at the 3000 MJ/h cap is approximately:
≈ 73 – 79 kg per hour (that's right in with what Tommy said).
(depending on the certified fuel’s LHV)


To convert to Volume Flow Using Density
FIA fuel density range at 15 °C is:
- 720–785 kg/m³ (or 0.720–0.785 kg/L).

Now convert mass flow to litres per hour:

Volume flow (L/h)=Mass flow (kg/h)
                   Density (kg/L)

Lower end of density + lower LHV (worst-case high volume)
- 79 kg/h ÷ 0.720 kg/L ≈ 110 L/h

Upper end of density + higher LHV (lowest volume)
- 73 kg/h ÷ 0.785 kg/L ≈ 93 L/h

[Tommy Cookers]

... What Mattia Binotto is revealing is deplorable for the sport.
Could someone explain .... why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? ...
Ferrari's PU in 2019 complied with the regulations... but not with the spirit of the regulations...

could someone explain how the 2026 Ferrari doesn't exceed 16:1 at the design rpm and temperature ....
when at such rpm rods and crankshaft at TDC deflect upwards so as to increase significantly CR above the static CR
(as has been posted in another thread)

[mzso]

What Mattia Binotto is revealing is deplorable for the sport. Could someone explain why Ferrari's PU wasn't compliant with the regulations in 2019, forcing them to restrict their engine, and why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? If i remember correctly, in 2019, the fuel flow measurement of Ferrari's PU was compliant at the measurement intervals, but not between two measurement points. In other words, Ferrari's PU in 2019 complied with the regulations (measured flow) but not with the spirit of the regulations. I'm just trying to understand this situation that distorts the competition.

That was clearly illegal, it was only impossible to detect at the time. They got like two years with extra power because of that.
Here it's clearly stated that the 16:1 is to be measured at ambient temperatures. Not to mention that due to heat expansion the ration decreases for all engines to some degree. So none has 16:1 when running.

[diffuser]

What Mattia Binotto is revealing is deplorable for the sport. Could someone explain why Ferrari's PU wasn't compliant with the regulations in 2019, forcing them to restrict their engine, and why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? If i remember correctly, in 2019, the fuel flow measurement of Ferrari's PU was compliant at the measurement intervals, but not between two measurement points. In other words, Ferrari's PU in 2019 complied with the regulations (measured flow) but not with the spirit of the regulations. I'm just trying to understand this situation that distorts the competition.

That was clearly illegal, it was only impossible to detect at the time. They got like two years with extra power because of that.
Here it's clearly stated that the 16:1 is to be measured at ambient temperatures. Not to mention that due to heat expansion the ration decreases for all engines to some degree. So none has 16:1 when running.

The at Ambiant temperature was only ssen in Oct 2025. The inclusion of the “at ambient temperature” requirement happened as part of the Technical Regulations update for the 2026 Formula 1 season, with the wording publicly acknowledged around October 2025 when the regulation draft language was finalized and communicated to teams.

[Bill]

What Mattia Binotto is revealing is deplorable for the sport. Could someone explain why Ferrari's PU wasn't compliant with the regulations in 2019, forcing them to restrict their engine, and why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? If i remember correctly, in 2019, the fuel flow measurement of Ferrari's PU was compliant at the measurement intervals, but not between two measurement points. In other words, Ferrari's PU in 2019 complied with the regulations (measured flow) but not with the spirit of the regulations. I'm just trying to understand this situation that distorts the competition.

That was clearly illegal, it was only impossible to detect at the time. They got like two years with extra power because of that.
Here it's clearly stated that the 16:1 is to be measured at ambient temperatures. Not to mention that due to heat expansion the ration decreases for all engines to some degree. So none has 16:1 when running.

The at Ambiant temperature was only ssen in Oct 2025. The inclusion of the “at ambient temperature” requirement happened as part of the Technical Regulations update for the 2026 Formula 1 season, with the wording publicly acknowledged around October 2025 when the regulation draft language was finalized and communicated to teams.

A wing can pass a static test but if it flexes it will not be allowed to run even though it passed .so it fia allow all those alleged tricks on compression ratio because they pass the test at ambient temperature it will imply that the wings of mclaren and redbull that got banned were infact legal.they is ground for fia to be sued for lost points and revenue.

[Badger]

That was clearly illegal, it was only impossible to detect at the time. They got like two years with extra power because of that.
Here it's clearly stated that the 16:1 is to be measured at ambient temperatures. Not to mention that due to heat expansion the ration decreases for all engines to some degree. So none has 16:1 when running.

The at Ambiant temperature was only ssen in Oct 2025. The inclusion of the “at ambient temperature” requirement happened as part of the Technical Regulations update for the 2026 Formula 1 season, with the wording publicly acknowledged around October 2025 when the regulation draft language was finalized and communicated to teams.

A wing can pass a static test but if it flexes it will not be allowed to run even though it passed .so it fia allow all those alleged tricks on compression ratio because they pass the test at ambient temperature it will imply that the wings of mclaren and redbull that got banned were infact legal.they is ground for fia to be sued for lost points and revenue.

Nonsense, every wing flexes, and 99% of the time the FIA looks the other way.

[gearboxtrouble]

The CR issue is a storm in a teacup imho. The non Mercedes and RBPT manufacturers are making noise because it is important to confirm what is and isn't allowed to direct future development. Every engine will be running a CR > 16 at operating temperature, the only difference is that two of them were designed to deliberately maximize what is a normal fact of thermodynamics. I very much doubt it will be something like the Mercedes is at 18 and the others are at 16 at all times which are the numbers used to generate the worst case numbers everyone is throwing around. The reality is there are many other factors at play that could have a much bigger impact on overall performance than just the CR. Fuel composition is likely going to be a major factor this season with the rules allowing a 17% range in energy density thats measured in a homologation test to calibrate a fuel flow meter. Imho this could be a major area of gamesmanship and its perfectly plausible that (hypothetically) Shell develop a fuel for Ferrari thats 15% more energy dense than the Petronas one in the Mercedes that reaches the same efficiency at a lower CR, allowing them to start the race with a lower fuel weight. Put simply, this is one small thing in a much larger picture that will determine overall efficiency and performance.

[Tommy Cookers]

... What Mattia Binotto is revealing is deplorable for the sport.
Could someone explain .... why these PUs that manage to circumvent the 16:1 ratio are deemed compliant in 2026? ...
Ferrari's PU in 2019 complied with the regulations... but not with the spirit of the regulations...

could someone explain how the 2026 Ferrari doesn't exceed 16:1 at the design rpm and temperature ....
when at such rpm rods and crankshaft at TDC deflect upwards so as to increase significantly CR above the static CR
(as has been posted in another thread)

at TDC before the power stroke and 12000 rpm ......

the rod will be 0.4 mm longer due to c.4 tons (inertial-pressure) load on the rod (piston&rod mass 1200 gm) ....
and the crank will be eg deflected up at the big end journal adding (a guess) 0.2 mm to the above ....
giving to a 'running' geometric CR of 19:1 in an engine with 'bathtub' combustion chamber and 16:1 nominal CR
(a deflection far less than in Austin 7 engines that eg Colin Chapman and Eric Broadley used in their 750 MC days)

thermal expansion effects on CR are nil if all the parts have the same expansion coefficient and temperature
yes the thermal expansion could reduce (or increase) the 19:1 CR depending on the metals used for each part