2026 F1 Power Unit Explained: The 50/50 Engine Revolution

Formula 1 has used a hybrid power unit architecture since 2014. For twelve seasons, teams built their cars around a 1.6-liter turbocharged V6 engine working alongside two motor-generator units: the MGU-K on the drivetrain and the MGU-H on the turbocharger shaft. That configuration produced the most thermally efficient internal combustion engines ever built for a motorsport application, but it also created power units of extraordinary cost and complexity that made it practically impossible for a new manufacturer to enter the sport without a decade-long development program.

The 2026 technical regulations keep the basic architecture of a turbocharged V6 paired with an energy recovery system, but they remove one of its most complex components, substantially increase the power of the other, and rebalance the contribution of combustion and electrical power so that both sides of the system contribute approximately equally to the car’s total output. The result is a power unit that is meaningfully different from its predecessor in both engineering philosophy and competitive character.

The Internal Combustion Engine

The internal combustion engine at the core of the 2026 power unit retains the same fundamental specification as the unit it replaces: a 1.6-liter, 90-degree V6 configuration with a single turbocharger and direct injection. The bore and stroke dimensions, the engine speed limits, and the basic combustion cycle philosophy carry over from the previous regulations, preserving the decades of development knowledge that manufacturers have accumulated around this architecture.

Output and the Reduction From 2025

The ICE in a 2026 power unit produces approximately 400 kilowatts of power, equivalent to around 536 horsepower. This figure represents a deliberate reduction from the approximately 550 kilowatts that the best 2025 power units extracted from their combustion side. The reduction is not a consequence of less sophisticated engineering; it reflects a regulatory decision to rebalance the total power budget between the combustion and electrical components, with the freed-up performance to be provided instead by the expanded MGU-K.

The fuel energy flow limit is the primary regulatory tool that constrains ICE output. For 2026, the maximum fuel energy flow is 3000 megajoules per hour, equivalent to a mass flow rate of approximately 70 kilograms of fuel per hour. The previous limit was 100 kilograms per hour, meaning the combustion side of the power unit receives substantially less fuel energy than before. Manufacturers have responded to this constraint by pushing combustion efficiency to new extremes, extracting as much useful power as possible from the reduced fuel flow while managing the thermal loads that high-efficiency combustion cycles produce.

The fuel flow meter, which measures and enforces the 3000 megajoule per hour limit, is an FIA-supplied homologated component. It sits on every car’s fuel circuit and its readings are available to the FIA’s technical team in real time through the telemetry system. Any exceedance of the fuel flow limit during a session is a technical regulation violation that carries the same consequences as any other breach of the technical rules.

Advanced Sustainable Fuel and the ICE

Every 2026 Formula 1 car runs on Advanced Sustainable Fuel, a specification defined in Article 16 of the technical regulations. The fuel contains no new fossil carbon; its carbon content is derived from non-food biomass, municipal waste, or atmospheric carbon capture, and the production process must be powered by renewable electricity. The Research Octane Number requirement of between 95 and 102 RON means the fuel’s anti-knock characteristics are broadly comparable to the fossil-derived fuels it replaces.

The transition to Advanced Sustainable Fuel has required manufacturers to revisit their combustion calibration, injection timing, and thermal management strategies. The chemical composition of the new fuel differs from fossil-derived racing fuel in ways that affect combustion characteristics, even if the fuel is designed as a drop-in replacement that does not require fundamental engine modifications. The manufacturers who have spent the most time understanding these differences in their simulation and dyno work will have an advantage in extracting maximum performance from the reduced fuel flow allowance.

The race fuel allowance is 70 kilograms, down from 110 kilograms under the previous regulations. This reduction of more than one third affects race strategy directly. Teams have less margin for fuel-burning in the early laps, less buffer for safety car periods that delay fuel consumption, and less room for error in their fuel load calculations before the race. The 70-kilogram allowance also means the car starts a race with less fuel mass than before, contributing to a lower starting weight that improves early-lap performance.

The MGU-K: A Transformed Component

The motor-generator unit on the kinetic side, the MGU-K, is the component that has changed most dramatically between the 2025 and 2026 power unit specifications. Where it was previously a supplementary performance booster adding around 160 horsepower to the system, it is now a co-primary power source delivering nearly 470 horsepower, nearly equal to the contribution of the internal combustion engine itself.

From 120kW to 350kW

The MGU-K’s maximum continuous output has increased from 120 kilowatts to 350 kilowatts. This is not a small incremental step; it is a fundamental change in the component’s role within the power unit. At 120 kilowatts, the MGU-K provided a meaningful but secondary contribution to acceleration. At 350 kilowatts, it delivers more power to the rear wheels in its operating range than many entire race cars in other series produce from their complete powertrains.

The physical consequences of this output increase are significant. The minimum weight specification for the MGU-K assembly has risen from 7 kilograms to 16 kilograms, reflecting the larger motor windings, stronger structural components, and expanded thermal management provisions required for the higher power levels. The geared connection between the MGU-K and the drivetrain is separately specified at a minimum of 4 kilograms, and the entire assembly is now required to sit within the survival cell rather than in the rear of the car as was possible with the lighter 120-kilowatt unit.

The cooling requirements for the 350-kilowatt MGU-K are substantially greater than for its predecessor. The Energy Store, which stores and supplies the electrical power the MGU-K consumes and generates, is cooled by dielectric fluid, a non-electrically-conductive oil that can come into direct contact with the battery cells without creating short circuits. The cooling system operates at temperatures in the region of 50 degrees Celsius. The larger radiator packages required to manage these thermal loads contribute to the changes in sidepod and bodywork design that distinguish 2026 cars visually from the previous generation.

Energy Recovery: 9MJ Per Lap

The MGU-K recovers energy from the car through three mechanisms. Under braking, the motor runs as a generator, converting the kinetic energy of the car’s deceleration into electrical energy that flows into the Energy Store. During coasting, where the driver is neither accelerating nor braking hard, the MGU-K can harvest smaller amounts of energy from the drivetrain. On throttle, the turbocharger’s excess energy, which would previously have been managed by the MGU-H, can now be harvested indirectly through changes to the engine’s operating point that feed additional mechanical energy to the rear axle and through it to the MGU-K.

The maximum energy that the MGU-K can recover per lap is 9 megajoules. Given the Energy Store’s maximum usable capacity of 4 megajoules delta state of charge, the 9 megajoules per lap recovery limit means the battery cycles through its usable capacity more than twice per lap at theoretical maximum recovery rates. In practice, recovery rates vary substantially through the lap, with the heaviest braking zones providing the majority of recovery energy and the medium-speed and high-speed sections contributing less.

At maximum recovery and deployment rates, the hybrid component of the power unit is available at full output for approximately 25 seconds per lap, which is a significant portion of the lap time at most Formula 1 circuits. The precise distribution of that deployment across the lap is managed through the recharge and deployment maps that teams load onto the Standard ECU before each session. Drivers can select between pre-programmed profiles to manage energy availability, and can modify the deployment balance through the steering wheel controls during the lap.

The Rampdown Function

The MGU-K rampdown is one of the more technically specific elements of the 2026 power unit regulations. At speeds below 290 kilometers per hour, the MGU-K can deploy its full 350 kilowatts to the rear wheels. Above 290 kilometers per hour, the regulations introduce a progressive reduction in available electrical power. By the time the car reaches 355 kilometers per hour, the MGU-K’s contribution to propulsion has reduced to zero.

The rampdown exists to prevent the combination of X-mode aerodynamics and maximum hybrid output from producing terminal velocities that would be unsafe on the fastest circuits. A car in X-mode already has dramatically reduced aerodynamic drag compared to a car in its standard configuration. Adding 350 kilowatts of additional propulsive force at those drag levels without a speed ceiling would produce top speeds that exceed the safety parameters of even the fastest circuit sections in Formula 1’s calendar.

The rampdown function applies to all cars in standard operation. The shape of the rampdown curve, starting at 290 kilometers per hour and reaching zero at 355 kilometers per hour, has been set by the FIA based on analysis of terminal speed data across the full calendar of circuits. It applies to both qualifying and race conditions, meaning that even with the benefits of X-mode and maximum hybrid output, the power unit is physically limited in the speed contribution it can make at the upper end of the speed range.

The MGU-H: Removed

The Motor Generator Unit, Heat side, which sat on the turbocharger shaft and was capable of both extracting energy from exhaust gas heat and using stored electrical energy to motor the turbocharger to eliminate lag, has been deleted entirely from the 2026 power unit specification. Its removal is one of the most significant single changes in the entire regulatory package, with consequences that extend from power unit engineering to the commercial viability of the regulations for new entrants.

What the MGU-H Did

The MGU-H was positioned between the turbine and compressor wheels on the turbocharger shaft. In energy recovery mode, exhaust gas flowing through the turbine drove the shaft, and the MGU-H converted the rotational energy into electrical power that could be stored in the Energy Store for later deployment. In motor mode, stored electrical energy was used to spin the compressor independently of exhaust gas pressure, eliminating the turbo lag that conventional turbocharged engines experience at low engine speeds and throttle opening.

The combination of these functions made the MGU-H extraordinarily valuable. It improved low-speed throttle response by effectively eliminating turbo lag, recovered energy that would otherwise have been wasted as exhaust heat, and allowed the turbo to operate at a different speed from the one dictated purely by exhaust gas pressure. The thermal efficiency levels that Formula 1 engines achieved under the 2014 to 2025 regulations, exceeding 50 percent in the best cases, were made possible in large part by the MGU-H’s ability to recover waste heat energy.

The component was also of extraordinary engineering complexity and cost. Developing an MGU-H required years of work and tens of millions of dollars in investment, with the operating speeds involved, exceeding 100,000 rpm on the turbocharger shaft, demanding materials and manufacturing techniques that were far beyond the capabilities of most engineering organizations. For the existing manufacturers who had developed the technology over more than a decade, this created a barrier to competition that protected their investment. For new entrants attempting to build a competitive power unit from scratch, it represented a near-insurmountable development challenge.

Why It Was Removed and What Replaces It

The MGU-H was removed from the 2026 specification at the request of incoming manufacturers who identified it as the primary barrier to entering Formula 1 as a power unit supplier. Honda, Audi, and Ford’s partnership with Red Bull Powertrains all made their involvement conditional on the MGU-H’s deletion, arguing that without this change, the development timeline and cost required to produce a competitive unit made participation commercially indefensible.

The functions previously performed by the MGU-H are partially compensated for in the 2026 architecture. The elimination of turbo lag, which the MGU-H handled by motoring the compressor at low speeds, is now addressed through a combination of turbocharger design optimization and changes to how the ICE manages its operating range in the absence of the motor assist. The energy recovery that the MGU-H provided from exhaust heat is not replaced directly, which is one reason why the overall thermal efficiency of the 2026 power unit is expected to be lower than the figures achieved by the best 2025 units despite the continued advancement in combustion engineering.

The consequence for drivers is a change in throttle response characteristics, particularly when exiting low-speed corners where the MGU-H’s anti-lag function was most valuable. Teams and engine manufacturers have invested heavily in software and mechanical solutions to manage this transition, and the first races of 2026 will provide the first on-track evidence of how successfully different manufacturers have addressed the loss of one of the most technically impressive components in motorsport history.

The Energy Store

The Energy Store is the battery unit that sits within the survival cell and manages the electrical energy flowing between the MGU-K and the rest of the power unit. Its specification under the 2026 regulations reflects the substantially increased demands placed on it by the 350-kilowatt MGU-K.

Capacity, Charging, and Operating Limits

The maximum usable capacity of the Energy Store, expressed as the maximum delta state of charge, is 4 megajoules. This figure represents the total electrical energy available for deployment from the battery at any given moment, and it sets an upper limit on how much stored power can be released in a single sequence before the Energy Store requires replenishment through recovery. The 4-megajoule limit is not the total physical capacity of the battery; it is the maximum swing in charge level the regulations permit during operation, a distinction that affects how teams calibrate their energy management strategies.

The interaction between the 4-megajoule storage limit and the 9-megajoule per lap recovery limit means that the battery does not simply accumulate energy across the lap and discharge it all at once. Instead, energy flows in and out of the store continuously, with the instantaneous state of charge at any point in the lap depending on the balance between recovery and deployment in all the preceding lap sections. Modeling this dynamic accurately is one of the most computationally demanding aspects of race simulation and strategy work.

The Energy Store operates at high voltage, consistent with the safety and performance requirements of a 350-kilowatt electrical system. The cooling system using dielectric fluid prevents the battery cells from exceeding their safe operating temperature range during periods of intense cycling, such as back-to-back braking zones where high recovery is followed immediately by high deployment for corner exit acceleration. The physical dimensions and mounting provisions of the Energy Store are specified in the regulations to ensure it can be accommodated within the survival cell’s structural envelope without compromising the cell’s crash performance.

The Overtake Mode Energy Provision

When a driver uses the MGU-K override proximity function, described in the aerodynamics section in the context of its interaction with X-mode, the regulations provide for an additional 0.5 megajoules of energy recovery allowance above the standard 9 megajoules per lap. This additional recovery capacity is available only on the lap following an overtake mode deployment, giving the team the opportunity to rebuild Energy Store charge that was consumed during the override phase.

The 0.5 megajoule additional allowance is a relatively small amount compared with the total lap recovery budget, but it provides meaningful support for strategies that involve sustained use of the MGU-K override across multiple consecutive laps. Teams executing an overtaking sequence that extends over several corners and straights, requiring repeated override activations, can plan their energy budgets around the additional recovery provision rather than accepting a growing energy deficit with each successive deployment.

Five Manufacturers Creates New Competition

The 2026 regulations are contested by five power unit manufacturers, of which one is entirely new and two have returned to the sport in new or expanded capacities. The combination of manufacturers with deep development histories and those working from clean-sheet designs creates a competitive environment that is genuinely unpredictable in its opening phase.

The Established Manufacturers

Mercedes and Ferrari are the continuity names, carrying their manufacturer status directly from the previous era and with it years of accumulated knowledge about extracting performance from the turbocharged V6 hybrid architecture. Mercedes powers the works team alongside Williams, Alpine, and World Champions McLaren, giving it the broadest customer footprint on the grid. Ferrari supplies the works team, Haas, and new constructor Cadillac.

Honda returns as a fully-fledged manufacturer after several years in a transitional supply arrangement with Red Bull and AlphaTauri. For 2026, Honda supplies Aston Martin with a power unit developed entirely to the new specification. The lessons from Honda’s previous involvement in the 2014 to 2025 era, including the period when it struggled to close the performance gap to the leading units, have informed the architectural decisions made for the 2026 program.

The New and New-ish Entrants

Red Bull Powertrains, in partnership with Ford, supplies both Red Bull teams with a power unit built around the 2026 specification from the outset. Ford’s involvement as an official partner brings a major American automotive brand back into Formula 1 in a formal capacity for the first time since the Ford Cosworth era, and the collaboration has been structured entirely around the new regulations rather than adapting an existing architecture.

Audi, having taken over the Sauber operation, is the sole genuinely new manufacturer on the 2026 grid. Its power unit has been developed without any previous Formula 1 engine program to draw on, making it the most closely watched new entry in the field. Cadillac, entering as an 11th constructor, runs as a customer of one of the existing manufacturers while General Motors develops its own power unit for a future date. The five-manufacturer lineup reflects how successfully the 2026 regulations have made Formula 1’s power unit program commercially viable for major automotive groups.

Want more F1Chronicle.com coverage? Add us as a preferred source on Google to your favourites list for the best F1 news and analysis on the internet.