The key ingredients changing as F1's 2026 engine war shapes up

It was almost a decade ago that Formula 1’s turbo-hybrid era began. The move away from the 2.4-litre atmospheric V8s to the current 1.6-litre V6 turbo engines augmented by electric motors was, in its infancy, not entirely auspicious; complaints over a lack of noise were united with evident gulfs between each powertrain’s performance level. While many still yearn for a return to the ear-splitting V10 era, most have come to tolerate the modern-day soundscape of guttural roars rather than banshee-like screams, while performance levels have converged over the past nine and a bit years.

PLUS: Why F1's hard-to-love turbo-hybrid decade has been so important

For 2026, the turbo-hybrid powerplants will enter their next generation. F1’s current formula will therefore have been in service for 12 full years, making them longer-lived than many of the more celebrated engine formula spans: including the 2006-13 V8s, the 1995-2005 three-litre V10 (plus occasional V8 and V12 interlopers) era, and the 1987-94 expansion of the naturally aspirated engines to 3.5 litres.

Similarities will remain with the projected new power units, and a 1.6-litre V6 internal combustion engine will continue to underpin the overall package. But there are a range of key changes aimed at keeping Formula 1 relevant to not only the growing cast of automotive suppliers involved, but to the changing demands of the industry. With the growing repertoire of all-electric championships within the world of motorsport, F1 wants to prove that the internal combustion engine has a long-term future…

Greater emphasis on hybrid

When the current powertrain rules emerged, F1 had not done a particularly good job of promoting them as highly efficient hybrid engines that could churn out masses of power, all while using far less fuel than the previous naturally aspirated V8s. Now their value has been recognised – and F1 wants to expand upon that.

Currently, the MGU-K positioned on the rear axle can produce about 160bhp, producing anywhere between a 90/10 and an 80/20 split in the bias towards the internal combustion engine for propulsion. That’s set to shift to a formula approaching 50/50; the MGU-K is going to be responsible for 350kW (470bhp) of the total power output, with the internal combustion engine producing the rest. That’s the same circa-1000bhp output as the current powertrains, but achieved with less fuel.

Photo by: Mercedes AMG

Thomas says although the base 1.6-litre V6 turbo characteristics remain the same, the overall combustion system will change comprehensively

But the much-maligned MGU-H will be removed from the overall package. While useful in the environs of F1, where drawing waste energy from a turbine and using it to spool it back up to eliminate lag was beneficial, it has found little use in the wider automotive industry. To keep the current manufacturers involved in F1 and to tempt new ones in, deleting the MGU-H seemed to be the easiest way to satisfy both camps.

The overall mass of the power unit must be at a minimum of 185kg, up from 151kg in the current regulations, which allows for a weightier internal combustion engine and a larger motor generator unit to produce the upscaled level of power. But while the base 1.6-litre V6 turbo characteristics remain the same, the overall combustion system will change comprehensively. Mercedes engine chief Hywel Thomas explained that “it’s going to be a completely different combustion system, as the amount of fuel is reduced.

“There’s some details around compression ratio. There’s details around permissible boost pressure. So there’s just a different set of constraints on us. And that different set of constraints means that, while I’m sure to some eyes it will look very similar, it’s going to be completely different.”

F1 is hoping that the “drop-in” fuels produced can be upscaled to mass production since these fuels require no modifications to an existing internal combustion engine

Thomas added that the 2026 rules might, following the removal of the MGU-H, deliver an aspect to the new powertrains that many have found to be sorely lacking in the current specification. “With the removal of the MGU-H, even though we have still got a turbocharger, it won’t be removing as much of the energy as we’re currently doing. We know the combustion engine will be less efficient and so that will, by physics, mean that there’s more noise.”

Sustainable fuels

Fossil fuels will be consigned to F1’s past in 2026, with sustainable fuels feeding the new engines. Although the rules are intended to minimise the effect of a war between energy giants, they will nonetheless seek to accelerate their fuel technology in the F1 battleground. This will come down to composition, where there’s a degree of flexibility with how each supplier produces their hydrocarbon fuel – so long as it is not derived from feedstocks that affect the global foodchain. This must also tie into F1’s ‘zero carbon’ target.

It is expected that the compositions between fuel suppliers may vary; biowaste-derived ethanol can be blended with synthetic e-fuels, the latter becoming a growing technology as carbon captured from the atmosphere is forced to bond with hydrogen. As long as hydrogen gas is produced using only renewable energy, this is a sound – but energy-intensive – manner of producing a carbon-neutral fuel. Ultimately, the method of production will be largely open.

Photo by: Red Bull Content Pool

F1's new regulations have proven attractive to OEMs, with Ford signing up as a partner of the Red Bull Powertrains project

To mitigate an escalating arms race between fuel suppliers, the fuel flow limits have been changed. Rather than measuring the amount of fuel injected into the engine by mass, the 100kg/hour limit will now switch to a limit based on energy, pencilled in at 3000MJ/hour. This hence prioritises efficiency in the powertrain, rather than stuffing potential energy into a single drop of fuel.

F1 is hoping that the “drop-in” fuels produced can be upscaled to mass production; since these fuels require no modifications to an existing internal combustion engine, it ensures that the products seen powering 20 (or 22, perhaps?) F1 cars can translate to the garage forecourt.

Increased manufacturer competition

The 2026 engine regulations have attracted the most manufacturers on the grid since 2008, with the two seasons tied on having six engine suppliers. Mercedes, Ferrari, and Renault have maintained their interests, and Honda makes a ‘return’ having realistically never left the championship. Red Bull Powertrains has linked up with Ford, the Blue Oval returning to the grid for the first time since it left at the end of 2004, and Audi becomes an F1 constructor for the first time through its majority purchase of Sauber.

The circumstances of having six manufacturers on the grid, however, are very different; back in 2008, there was something of a supplier drain when financial crises and constraints prompted Honda, BMW and Toyota to depart over the next two years, and it was only at the behest of Bernie Ecclestone and Max Mosley that Cosworth was returned to the fold for 2010.

This time around, new manufacturers have actually been tempted in by the progression of the regulations. It’s not just F1’s growing popularity and more favourable financial terms that have provided the incentive to join, although those will have surely greased the wheels.

Initial hybrid introductions were not overwhelmingly popular in 2009 when KERS (the precursor to the MGU-K) was made available. BMW, Renault, McLaren-Mercedes and Ferrari produced their own 80bhp motors, but the first two dropped it partway through the season having found limited potential. Ultimately, it attracted no new manufacturers – it’s only in recent years that the more sophisticated hybrid systems have been of interest…

Photo by: Sutton Images

F1 will have more engine manufacturers in 2026 than at any point since 2008, the last for Honda as a works entry before BMW and Toyota quit the year after

Key battlegrounds

Teams have a key concern about the 2026 engine specifications: in their simulations, excessive lifting was required to charge the battery enough to deliver the full power promised by the motor generator unit. Max Verstappen reported that in his earliest simulations of the 2026 package, he had to downshift along the straight at Monza to help recharge for the rest of the lap.

F1 chief technical officer Pat Symonds refuted that, explaining that more advanced simulations show that this would not be necessary following modifications to the rulings. He stated that “the performance profile of a 2026 car in simulation now doesn’t look terribly different to 2023”, given the evolution of the regulations that were initially put out.

Ultimately, it will be up to the teams to find ways of recovering energy throughout the course of a lap to ensure that the 350kW MGU-K maintains its up-time for as long as possible. Determining where the car needs the full 1000bhp and where it doesn’t will be key to that, so mapping out usage will continue to play a part. Like Formula E, software will become a hotly contested area for performance gains.

The concerns over not having enough energy recovery do not extend to every circuit, merely the very fast ones, but Symonds and F1 are adamant that this won’t be a problem once 2026 rolls around

Powertrain efficiency will continue to be important, as per the 3000MJ/hour energy flow regulation set out for 2026. The current internal combustion engines are just over 50% efficient, meaning that they convert over half of the raw energy available in an uncombusted fuel into forward propulsion; this may drop slightly with the removal of the MGU-H, since teams may burn more fuel off-throttle to help spool the turbo up and eliminate lag on corner exit.

Active aerodynamics are also set to tie in to the 2026 regulations, and F1 is still in the process of defining the boundaries for this. Although the overall desire is to create a situation that eliminates DRS trains, the active aero package will also have a role to play in helping the cars regenerate energy to ensure that the full 350kW of power is available from the motor. It is expected that, to replace DRS, wings will be flattened on the straights; with the reduced drag, this puts much less demand on using the energy in the battery pack to generate speed.

The concerns over not having enough energy recovery do not extend to every circuit, merely the very fast ones, but Symonds and F1 are adamant that this won’t be a problem once 2026 rolls around. It’s likely just posturing – and once F1 reaches its all-new rules cycle, don’t be surprised if those issues don’t end up occurring.

Photo by: Zak Mauger / Motorsport Images

Will Verstappen's concerns about having to downshift on Monza's long straights to charge the battery be rendered moot as development progresses?