The F1 Energy Flow Diagram: How Power Moves Through a 2026 Car

Understanding a 2026 Formula 1 power unit is easier when you trace the journey energy takes from the moment fuel enters the system to the moment power reaches the rear wheels. Unlike a conventional combustion engine, where the energy path runs in a single direction from fuel to crankshaft to wheels, a 2026 car manages energy flowing in multiple directions simultaneously, with the same rear axle both receiving power from the MGU-K and returning harvested energy to the Energy Store depending on what phase of the lap the car is in.

Energy In: The Fuel System

From Tank to Combustion Chamber

The energy journey begins in the fuel bladder, a safety-cell fuel container holding up to 70kg of 100% non-fossil sustainable petrol. From the bladder, fuel is drawn through the supply system and metered through the homologated Gill fuel flow sensor, which measures the energy flow rate in megajoules per hour. The regulations cap this at 3000 MJ/h, equivalent to approximately 70kg per hour, which sets an absolute ceiling on the rate of energy extraction from the fuel regardless of how the team calibrates the rest of the power unit.

Fuel reaches the injectors and enters the combustion chamber, where it mixes with compressed air forced in by the turbocharger. The ignition event releases the fuel’s chemical energy as heat. At an LHV of 38-41 MJ/kg, 70kg of race fuel contains between 2,660 and 2,870 MJ of chemical energy. Not all of this becomes mechanical work: a typical internal combustion engine converts around 40-50% of fuel energy into shaft power, with the remainder leaving as heat through the exhaust, cooling system, and friction. Formula 1 engines, operating at the edge of thermal efficiency, reach the higher end of this range. The full picture of how the 2026 power unit balances combustion and electrical energy sits at the center of the regulation changes for this era.

The Turbocharger’s Role

The turbocharger extracts energy from the exhaust gases that would otherwise be wasted. Hot, pressurized exhaust flows through the turbine wheel, spinning it at very high speed. The turbine shaft connects to the compressor wheel, which forces fresh air into the intake at above-atmospheric pressure, increasing the mass of air available for combustion and therefore the power output for a given displacement. In 2026, without the MGU-H to spin the turbo electrically during low-throttle phases, the turbocharger responds purely to exhaust gas energy, introducing more variable boost characteristics than the previous generation of cars exhibited.

Energy Conversion: The ICE to Crankshaft Path

Mechanical Power from Combustion

The combustion pressure acts on the pistons, converting the heat energy of combustion into reciprocating mechanical motion. The connecting rods and crankshaft convert that reciprocating motion into rotation. The crankshaft delivers approximately 400kW of mechanical power at peak output in 2026, down from higher levels in the outgoing era to reflect the roughly equal split between combustion and electrical contribution that the power unit regulations target. This mechanical power flows through the clutch and into the gearbox.

The gearbox, a mandatory eight-speed unit, multiplies torque and adjusts the speed relationship between the engine and the rear wheels. Power exits the gearbox through the differential and drives the rear wheels via the driveshafts and wheel carriers. The entire combustion-to-wheel path is a relatively conventional mechanical chain: the 2026 regulations specify materials and configurations for these components but do not change the fundamental mechanical architecture that has governed rear-wheel-drive Formula 1 cars for decades.

Energy Recovery: The Electrical Path

MGU-K Harvesting

The MGU-K sits on the rear axle side of the drivetrain and can operate in two modes during a lap. In harvesting mode, it acts as a generator, extracting kinetic energy from the rotating drivetrain and converting it to electrical energy. This happens primarily in two situations: when the driver lifts off the throttle and the car begins to decelerate, and under braking, where the MGU-K works alongside the rear brake-by-wire system to recover energy that would otherwise be dissipated as heat in the rear brake discs.

The harvested electrical energy flows through the power electronics to the Energy Store. The Energy Store, a lithium-ion battery system, accepts this charge and stores it as chemical energy. The regulations limit the harvest to a maximum of 9MJ per lap and require that the state of charge change per lap not exceed 4MJ. These two constraints together define the energy recovery envelope: the car can harvest aggressively in some phases of the lap if it is also deploying aggressively in others, as long as the net delta and the total throughput stay within their limits. The 2026 energy recovery guide covers how teams plan this budget across different circuit types.

From Energy Store Back to the Wheels

When the driver and energy management system call for electrical deployment, the stored chemical energy in the Energy Store converts back to electrical energy and flows through the power electronics to the MGU-K. The MGU-K operates as a motor in deployment mode, adding torque to the rear axle alongside the mechanical power from the ICE. The combined peak output of roughly 750kW, approximately 400kW from combustion and up to 350kW electrical, represents the highest available power in Formula 1 history and is the product of this two-path energy delivery architecture. The detailed mechanics of the MGU-K system and the Energy Store are covered in their dedicated articles.

Energy Out: Losses, Heat, and Efficiency

Where Energy Leaves the System

Not all the energy that enters the fuel bladder at the start of a race reaches the rear tyres as useful mechanical work. The combustion process rejects heat through the cooling system, accounting for a significant fraction of the fuel’s lower heating value. Exhaust gases carry energy away from the engine, though the turbocharger recovers a portion of this. Friction losses in the drivetrain, from the gearbox to the wheel bearings, convert some mechanical energy to heat. The MGU-K’s electrical conversion is not perfectly efficient, with losses in the motor windings and power electronics dissipated as heat.

The Energy Store itself loses energy in each charge and discharge cycle, and thermal management of the store at its target operating temperature of around 50°C is a continuous challenge during a race. Dielectric cooling keeps the cells within their operating window, but the cooling system itself consumes some of the power unit’s energy to operate. When all these loss pathways are totaled, the fraction of fuel energy that actually moves the car forward is considerably less than unity, and improving that fraction is one of the core engineering challenges driving development competition between the five power unit manufacturers in 2026. For the full picture of how these systems interact, the 2026 power unit guide traces the regulatory framework that governs each element of the energy path from tank to tyre.