How F1 cars use energy: what the new rear LED lights will show. The new F1 rear LED lights in 2026 will indicate how cars manage energy.

The new rear LED lights on Formula 1 cars will become a real indicator of energy management – a system to watch closely. A single flash shows that the MGU-K is no longer operating at full power, two consecutive flashes indicate that the electric motor generator is off, and when the lights flash repeatedly, super-clipping is active.

The 2026 F1 revolution revolves around the new Power Units, making energy management even more central than before. From the outside, however, understanding what phase a car is in will be far from simple: graphical information will remain limited, following the approach of previous regulations when FOM provided only basic indicators.

For safety reasons on track, though, it will still be possible to infer a car’s energy phase. The key reference will be the rear LED lights, which from this year will carry much more information than in the past.

At the rear, the central LED light has been redesigned with new functions and colors, also useful for identifying specific situations – from indicating a rookie driver to signaling different working programs, as seen in Barcelona testing with Aston Martin. Together with the two lights on the endplate, the LEDs in 2026 will become a richer, more informative tool – one to be interpreted carefully.

Until last year, the lights activated when the MGU-H was charging or, under braking, when the MGU-K recovered energy, flashing the LEDs. From this season, energy recovery will change even at full throttle, so the FIA modified the LED operation to provide a visual reference for observers.

There are three main uses of the lights, each linked to a specific energy recovery mode. A single flash means the MGU-K is still supplying energy to the system, but below the maximum 350 kW allowed. This affects the acceleration of the car ahead, which may no longer be as rapid as when the electric motor is delivering full power.

Two flashes indicate that the MGU-K is essentially “off”: it is not supplying or recovering energy. In this phase, the car moves forward relying solely on the internal combustion engine, which this year delivers just over 500 horsepower.

Conversely, when the rear LEDs flash rapidly and continuously, the signal is the opposite: the MGU-K is fully charging while the internal combustion engine continues to deliver full power, entering super-clipping. At high-speed zones, the driver may keep the throttle fully open while the MGU-K works against the engine to generate energy and recharge the battery.

This gives following drivers an immediate indication of rivals’ energy levels, but the main goal remains safety. During MGU-K charging, especially in super-clipping phases, sudden speed drops can occur. Warning the following car allows it to react in time and avoid potentially risky situations.

Teams will undoubtedly analyze the rear LED behavior carefully to gather data on competitors’ energy profiles. By combining these signals with telemetry, they can estimate how much power the MGU-K is delivering at specific track points or identify battery charging zones.

Beyond energy management, the LEDs can also indicate safety situations. In addition to showing energy modes, they may signal a Safety Car, a double yellow sector, engine shutdown on track, or, as in the past, that the car is on wet tires.

These new LED protocols transform the rear of the car into a real-time technical dashboard for fans and rival engineers alike. While the “super-clipping” phase might sound like a technical glitch to the uninitiated, the rapid flashing of the LEDs will soon become a familiar sight as drivers fight to balance raw speed with battery longevity.