F1 limits the fuel's chemistry and energy flow, the ERS-K's power and recharge, and each driver's season-long power-unit pool.

The governing rules and version used here

This page applies only to the 2026 FIA Formula One World Championship. The controlling public texts checked on 26 August 2026 are the FIA Formula 1 Regulations: Section A, General Regulatory Provisions, Issue 03 dated 25 June; Section B, Sporting Regulations, Issue 08 dated 5 August; and Section C, Technical Regulations, Issue 20 dated 5 August.

Section A Article A9.1.1 makes the 2026 regulations effective from 1 January 2026 for the calendar year. The latest Section B and C issues record World Motor Sport Council approval on 3 August 2026. These rules do not govern Formula 2, Formula E, endurance racing or a national single-seater series.

Legal fuel does not make every use of it legal

1. Specification: does the fuel satisfy FIA Article C16 and match an approved reference fuel?
2. Use: did all fuel pass through the homologated meter, stay inside the energy-flow limits and remain untouched during the prohibited period?
3. Proof: can the FIA obtain the required representative sample and verify the sensor data?

A car can therefore use an approved fuel and still breach a flow, refuelling or sampling requirement. Conversely, carrying less fuel than a rival is not by itself a breach.

No fuel may be added or removed during the Race

Section C Article C6.4.4 states the direct rule. Sporting Article B5.1.4 starts the protected period earlier: once a car has left the pit lane for its reconnaissance lap or laps, fuel may not be added or removed until the end-of-session signal.

Fuel handling at other permitted times is not unrestricted. Article B1.5.9 confines refuelling to the team's designated garage, caps transfer at 0.8 litres per second, requires the engine to be stopped and prescribes fire-protection and grounding precautions. When the car is running after leaving the garage, C6.4.2 says its fuel must not be colder than the lower of 10°C below ambient or 10°C; deliberate on-car fuel cooling is prohibited.

What “no refuelling” means: a pit stop during the Race cannot add fuel. It does not mean teams are forbidden to fuel or drain the car in the garage at every other point of the Competition; those operations have their own timing and safety rules.

The required sample is 0.70 litres

Under Section C Article C6.5.2, a team must ensure that a 0.70-litre fuel sample can be taken from the car at any time during the Competition. If, after a practice session, the car did not return to the pits under its own power, it must provide that sample plus the FIA-determined amount it would have consumed returning.

Articles C6.5.3–C6.5.4 require a representative sample from the collector area without starting the engine. Article C16.5 then governs testing: density must be within −0.15% to +0.25% of the pre-approval figure, and gas chromatography compares the Competition sample with the approved reference fuel. A change consistent with evaporative loss can conform. Mixing with another FIA-approved Formula 1 fuel used by the team can also conform up to 10% of the sample, but systematic abuse does not.

Electrical assistance tapers with speed

When Overtake is not active, the published C5.2.8 curve reduces the permitted propulsive ERS-K power as speed rises. It reaches zero at 345km/h. When Overtake is active, a different curve extends assistance to 355km/h. Both remain subject to the 350kW absolute ceiling and any event-specific limitations supplied under B7.2.

The FIA gives teams the circuit's Recharge values, Detection Gap and Detection and Activation Line positions at least four weeks before a Competition. It may make exceptional safety or orderly-conduct amendments before or during the event. There is therefore no single Detection Gap or Recharge setting that should be stated as universal for every Grand Prix.

Practice and qualifying do not use the Race gap test

Section B Articles B7.2.2–B7.2.4 distinguish two session families:

• Lap Time Classified Sessions: in free practice, Sprint Qualifying and Qualifying, Overtake is activated whenever it is enabled, so the driver may use it without first satisfying a following-distance test.
• Total Time Classified Sessions: in the Sprint and Race, Overtake is initially disabled and is enabled after the leader first crosses the Detection Line. A car's Overtake is activated at the Activation Line only if it was less than the event's Detection Gap behind another car at the Detection Line.
• Safety Car or low grip: Overtake is disabled. The Race Director may also disable and later re-enable it for safety.
• Notification failure: the team may request Race Director permission for manual operation, but then bears responsibility for using it only when the normal conditions are met.

Overtake changes the permitted electrical deployment curve. Driver Adjustable Bodywork has its own Article B7.1 activation rules; the two systems are related to passing performance but are not the same permission.

Fitting an element is not the final test

Under B8.2.8, an element is deemed used when the car's timing transponder shows that it has left the pit lane with that element. A replacement driver is treated as the original driver for power-unit usage, so changing the person in the seat does not create a fresh pool.

If more than one penalised element of the same type is introduced at one Competition, only the last one fitted may be used at later Competitions without a further penalty. This prevents a team from taking one event's penalty and banking several freely reusable units of the same type.

The first extra of each type costs ten places

1. First additional element of a type: ten grid places for the Race at the first Competition where it is used.
2. Each later additional element of that type: five grid places for the Race.
3. Different types: the drops are cumulative. An extra ICE and an extra MGU-K are assessed separately.
4. Appeal: Article B1.9.7 makes a grid drop imposed under B8.2 non-appealable.

These are the specific sporting consequences for exceeding the pool. A fuel, ERS or homologation non-compliance is a different kind of breach: it is reported and adjudicated under the general FIA process, and the applicable sanction depends on the rule and decision rather than automatically becoming the component grid penalty.

Not every internal replacement spends a new element

Article B8.2.9 requires the FIA to seal relevant power-unit elements before first use and adds post-Race seals to used ICE, turbocharger and MGU-K elements. If an FIA seal is damaged or removed, the affected part may not be used again unless the seal was removed under FIA supervision.

There are defined exceptions. PU-ANC components may be transferred between a driver's sealed elements under B8.2.4. Parts classified “EXC” and FIA-approved Minor Parts may be changed under B8.2.10–B8.2.11 without the normal B8.2.8 penalty, subject to homologation and seal-supervision conditions. The FIA may also authorise or mandate certain standard-supply component changes for safety, policing or reliability.

The FIA combines samples, sensors and records

• Fuel chemistry: approval samples, density checks and gas chromatography establish whether Competition fuel conforms to the reference.
• Fuel delivery: the homologated flow meter, FIA-measured fuel properties, pressure and temperature signals, and FIA data logging test the C5.2 and C5.9 limits.
• ERS: two mandatory DC sensors measure energy into and out of the Energy Store and ERS-K; C5.2.14 requires all relevant electrical flow to be measured.
• Component usage: declarations, the timing transponder, homologation dossiers and FIA seals identify which element entered a driver's pool and whether it remained controlled.

How to analyse a fuel, ERS or component question

1. Name the issue: fuel specification, fuel handling, energy flow, ERS deployment or season component use.
2. Name the session: practice/qualifying and Sprint/Race use different Overtake logic; the no-refuelling period has a defined start and end.
3. Apply the technical ceiling: check the absolute limit and any lower rpm, speed, state-of-charge, Recharge or event-specific limit.
4. Check the exception: examples include evaporative sample change, approved incidental fuel mixing, the ECU start-safety torque and supervised sealed-part work.
5. Identify the trigger: a PU element counts on pit-lane departure; Overtake eligibility is tested at the Detection Line; a sample must be available whenever requested during the Competition.
6. Choose the correct consequence: component overuse has specified grid drops; technical non-compliance goes through the FIA's general adjudication and sanction process.

Four shortcuts that produce the wrong answer

• “The car has a 3000MJ fuel tank limit.” The cited 3000MJ/h rule is an energy-flow rate.
• “350kW is available everywhere.” It is an absolute ERS-K ceiling; lower speed curves, Recharge and event settings also apply.
• “Overtake always needs a car within one second.” The FIA publishes the Detection Gap for each event, and qualifying does not use the Race gap test.
• “A new driver gets new engines.” B8.2.7 treats the replacement as the original driver for usage accounting.

Continue with Formula 1

• F1 2026 regulations overview
• Overtake and driver-adjustable bodywork
• Grid penalties and power-unit component rules
• Car weight, scrutineering and legality checks
• Formula 1 rules in five minutes

Event instructions can complete the picture

Section B requires the FIA to issue circuit-specific energy-deployment information, including the Detection Gap, line positions, Recharge limits and any permitted power-curve adjustments. Section A also allows FIA F1 Documents to supply binding technical installation details or non-binding guidance; those documents are ordinarily available through the FIA portal and may be confidential.

For a disputed real-world result, use the version in force at that Competition together with its FIA documents, Technical Delegate report and stewards' decision. Do not apply the figures on this 2026 page to another season without checking that season's published issues.