Letting a faster Formula 1 car through under blue flags is no longer simply a question of choosing the best racing line. Under the 2026 regulations, even partially lifting the throttle during a lapping manoeuvre can interfere with the MGU-K deployment curve, potentially using more electrical energy than intended and leaving a driver with a depleted battery. Esteban Ocon has explained why blue flags have consequently become a particularly difficult scenario for modern power-unit software.
The problem became especially relevant during the recent Hungarian Grand Prix, when a malfunction affecting the automatic blue-flag system created confusion for drivers who have become accustomed to receiving highly precise information. That normally includes the car number to which the warning applies, an important detail when several drivers are fighting closely and cannot simply rely on messages from their race engineers.
Hungarian GP blue-flag failure exposed a wider F1 problem
At a twisting circuit such as the Hungaroring, the malfunction inevitably created traffic situations that drivers were no longer used to dealing with in this way. Valuable tenths were lost during battles, as could be seen in the fight involving Oscar Piastri and Carlos Sainz. The circumstances formed part of the wider automated blue-flag problems at the Hungarian Grand Prix.
There is, however, an even more technically interesting aspect to blue flags under the current Formula 1 regulations: the way the power unit can change its behaviour when the driver alters the throttle to allow another car through.
With limited electrical energy available in the battery, teams have to manage deployment extremely precisely at different points around the lap. During the first part of the season, some unusual situations emerged in which even a small throttle lift of around three or four per cent could reset the MGU-K usage curve and result in more energy being consumed than originally planned.
The same behaviour can also influence wheel-to-wheel battles. Similar effects had already been seen at Suzuka through the high-speed 130R corner, illustrating how a seemingly minor change in throttle position can have consequences beyond the immediate moment.
Why MGU-K energy deployment has become so complicated
Formula 1 and the FIA have attempted to refine the regulations based on what emerged during the opening part of the season, making the new cars easier to manage. Considerable progress has been made, but the logic determining when electrical energy should be used and how it should be deployed remains highly complicated even for the teams themselves.
The challenge forms part of a much wider transformation in how drivers interact with Formula 1’s new generation of power units. Power-unit software and energy deployment have become central performance factors, with drivers having to understand not only what the car is doing mechanically but also how its programmed energy strategies will respond to their inputs.
“I think there have been a lot of improvements. Things like automatic launch, the power reset in certain areas, where we no longer have to manage the throttle manually. It had been a very long time since you saw lift and coast in qualifying, and now these are things that… it is quite crazy to say. But it is still better compared to when I started,” Esteban Ocon explained in Hungary.
However, Esteban Ocon believes that even if the FIA and Formula 1 continue along the positive path they have already taken, there will eventually be less room for further intervention. The restrictions built into the regulations will continue to define how and when the available energy can be used.
That is where the connection with blue flags becomes particularly interesting.
Esteban Ocon says engineering meetings now involve far more energy work
Technical meetings between drivers and engineers have become substantially more complicated because teams now have to discuss detailed mappings and precisely how electrical energy should be exploited. For teams running further down the order, that work can even include planning how the driver should behave when being lapped.
“There is much more work. Much more work compared to the past. Before, we focused much more on the car: the setup, the ride heights. Now we have to divide up how much work we do, and a large part of it concerns the energy-management side,” Esteban Ocon added.
The French driver explained that teams must prepare for numerous specific situations rather than concentrating only on conventional car setup.
“You also have to test the starting map, you have to test a slow lap, the formation lap. There are so many different scenarios where something can go wrong. And for us, blue flags are a killer scenario: if you lift on a straight at 60 or 70 per cent, you can see the battery suddenly dropping.”
The consequences can be significant once the battery has been emptied unexpectedly.
“You get to zero because you are using all the electrical power and the engine is not pushing, because you are lifting. If you do it on the wrong straight, it completely ruins you: you lose two seconds of race time until the car recharges on the following lap.”
Why letting a faster car through is no longer just about choosing the right place
In previous Formula 1 eras, choosing where to allow a faster car through was primarily about identifying the point at which the slower driver would lose the least possible time while still respecting blue-flag warnings and avoiding a penalty.
Under the 2026 regulations, that calculation has another major variable. Drivers and engineers must also consider how the power unit will interpret the lift or change of pace. The question is therefore no longer simply where to let another car through, but how to do so without disturbing the control system and its predetermined deployment sequence.
The issue illustrates why energy management has become such an important part of driving the current cars. Lewis Hamilton has also discussed how the latest regulations have altered the nature of racing, with energy management affecting the traditional wheel-to-wheel challenge that drivers have to deal with.
Why a partial throttle lift can continue draining the battery
If a driver does not lift completely off the accelerator and instead reduces the throttle only partially, the MGU-K can continue to deliver energy because it still has to complete its programmed reduction sequence.
The problem arises when the internal combustion engine is no longer operating at full load but the demand placed on the electric motor remains. The MGU-K can therefore continue deploying electrical energy at a point where that extra assistance may not actually be necessary, such as while the driver is deliberately slowing to be lapped.
This sensitivity to relatively small changes in throttle input has been one of the recurring technical themes of the new regulations. Charles Leclerc has previously highlighted how small throttle reductions can influence subsequent energy delivery, demonstrating how tightly driving technique and hybrid deployment are now connected.
“There are so many scenarios where, if something is different from what we expect, and in a race that always happens, things go wrong. So you try to plan the scenarios in advance, but sometimes you cannot predict all of them,” Esteban Ocon added.
In practical terms, that means the driver can suddenly end up using electrical energy differently from the strategy programmed before that particular phase of the race.
Why simply lifting completely is not always the answer
The only way to make the MGU-K stop delivering power immediately is to create a negative demand, which means the driver must lift completely off the accelerator to remove the request for electrical assistance.
That may sound like a straightforward solution, but it introduces another compromise. On high-speed circuits or particularly long straights, completely lifting off the throttle may cost considerably more lap time. The driver therefore risks losing more time than necessary simply to make sure the hybrid system behaves as intended.
This is what makes lapping strategy more complicated than before. The driver needs to respect the blue flags, minimise the time lost, avoid unnecessarily compromising the following part of the lap and simultaneously understand what the power-unit software is likely to do when the throttle input changes.
The problem is another example of the complexity behind energy deployment and power-unit management in modern Formula 1, where software behaviour can now have a direct influence on decisions that once depended largely on positioning and driving technique.
Isack Hadjar experienced a similar power-unit problem at Spa
There is another complication: drivers do not always know exactly how the power unit will react to an unusual situation. Isack Hadjar had already explained this at Spa when attempting to provide a tow for Red Bull teammate Max Verstappen.
“The difficult part is understanding what the engine is going to give you, because when you stop at the exit of Turn 14 and then have to put the power back down, the engine is a little confused, because you stopped without a real reason, and the software gets confused,” Isack Hadjar explained.
The unusual throttle sequence produced different results across the two attempts.
“So on the first attempt in Q3 I had far too much power and I pulled away from Max. On the second attempt, instead, I did not have enough, so Max was catching me, and I was not able to give him the tow for the entire section. It was very difficult to judge.”
The experience underlines the same underlying problem described by Esteban Ocon. Modern power-unit strategies are built around expected sequences of acceleration, lifting, recovery and deployment. When something unusual happens on track, the software can respond differently from what the driver anticipates.
F1’s new energy rules make unpredictable race situations difficult to programme
Formula 1 races are inherently unpredictable. Traffic, blue flags, battles, Safety Cars and unexpected changes of pace can all force a driver away from the sequence that engineers expected when preparing the energy strategy.
The challenge for teams is therefore to anticipate as many of these circumstances as possible, while recognising that it is impossible to programme every eventuality. Even sophisticated control strategies cannot remove the uncertainty created when a race situation requires the driver to behave differently from the assumptions built into the deployment map.
The FIA is already continuing to work on the broader hybrid framework, with further changes to energy deployment and recovery planned for 2027. For now, however, teams and drivers must continue working within the characteristics of the current system.
Blue flags are therefore no longer just a traffic-management issue. Under Formula 1’s 2026 power-unit regulations, the apparently simple act of moving aside can affect battery state, electrical deployment and race time well beyond the moment when the faster car passes. For drivers, that has turned one of racing’s most familiar procedures into another scenario that must be carefully planned with the engineers before the car even reaches the track.
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