Much has been said about how the removal of the MGU-H and the increased importance of the electric component will be the key to the upcoming season. However, the expected changes go far beyond the power unit architecture, extending to sustainable fuels and tyres, two elements that could prove just as decisive.
F1 2026 – The new regulations have now officially come into force. The updated rules introduce a 50-50 split between electric power and power generated by the internal combustion engine. However, the changes imposed by the FIA are far more deeply rooted than they may appear from the outside, affecting multiple areas of car design and operation.
The variables at play are extremely numerous. Alongside the increase in electric power generated by the MGU-K and the removal of the MGU-H, combined with several other modifications applied to the turbocharged V6 engine, Formula 1 will also introduce 100% sustainable fuels and a completely revised aerodynamic framework. These two changes are closely linked to the Power Unit and, unsurprisingly, carry significant importance for overall performance.
F1 2026: significant freedom in sustainable fuel production
The new hybrid power units will introduce, for the first time in Formula 1 history, the use of 100% sustainable fuels. Unsurprisingly, doubts and questions remain, given the scale and number of changes expected for the upcoming season. “I think sustainable fuels, at least initially, could represent a performance factor,” said Hywel Thomas, director of the Mercedes High Performance Powertrains department.
The FIA has guaranteed a certain degree of freedom in the development of these new sustainable fuels. Raw materials, known as feedstocks, are not subject to particularly restrictive limitations. At the same time, the FIA aims to avoid production systems designed specifically to manufacture certain substances solely for fuel creation. Likewise, the use of materials that are still considered ‘useful’, such as those suitable for human consumption, including vegetable oils, is prohibited. This is because the entire production system must be sustainable, not just the final product.
Paula Pérez-López, a specialist in environmental and social sustainability at MINES, highlighted this crucial aspect. “For a product to fall under the definition of sustainable, it must meet specific environmental, social and economic criteria and consider these aspects at every stage of its lifecycle,” the researcher explained. She also clarified that “the term sustainable is not the same as low-carbon. A product or process can be low-carbon but still produce high emissions or other pollutants, meaning it is not truly sustainable,” as she told Science Focus.
The FIA has appointed Zemo Partnership to create the Sustainable Racing Fuel Assurance Scheme, a third-party framework designed to certify the use of sustainable fuels in Formula 1. Under this scheme, fuels must be produced using at least 99% certified advanced sustainable components derived from renewable sources of non-biological origin, urban waste or non-food biomass.
Despite the considerable effort made by Formula 1 and its partners, some voices within the industry continue to urge caution. Fraser Browning, founder of Kurb Carbon, a consultancy firm specialising in emissions reduction strategies, shared his concerns about the project. “The main question is what impact this will have on Formula 1. Has it been done because it is part of the sport’s sustainability journey, or is it one of those initiatives without a realistic end goal?” the British expert said in comments to Science Focus.
At the same time, Browning also stressed the fundamental role that motorsport innovation has historically played in transferring advanced solutions to road cars. “I believe we would not have hybrid vehicles in their current form without sporting innovation. However, it needs to be done in a transparent and responsible way,” he added.
F1 2026: what will be the performance impact of sustainable fuels?
The challenge, however, does not lie solely in creating a fully sustainable product. It is more accurately described as a compromise, a balance that must be found between sustainability, performance and efficiency. It is precisely in this last area that several difficulties have already emerged.
This year, the governing body will introduce a new type of fuel control. Rather than imposing a direct limit on fuel flow, restrictions will be placed on energy flow. Until last season, limits were defined in terms of mass per unit of time. From now on, the limit will be expressed in terms of energy, measured in megajoules per hour, specifically 3000 MJ/h above 10,500 engine revolutions per minute.
This decision was far from accidental. Given the radical changes in fuel production, the FIA will assess how much chemical energy is released during combustion in order to apply more precise limitations. This opens the door to several development paths, each offering specific advantages and disadvantages depending on the characteristics of the fuel used. For the same mass, a fuel with higher energy density will allow teams to use a smaller quantity.
The difference in energy flow between two fuels with different energy densities can reach around 20 percent, a significant margin when considering its impact on the overall efficiency of the Power Unit. Some insiders suggest that fuel suppliers such as Shell, Petronas and Aramco have already reached a very high technical level. In particular, there is notable optimism surrounding Aramco’s work.
According to GP Blog, “Aston Martin’s fuel advantage puts them on par with Mercedes and Red Bull.” This is certainly an intriguing scenario, although it must be approached with appropriate caution. Sustainable fuels remain, by nature, less energy-dense than those derived from fossil fuels, which were traditionally easier to manage and optimise.
Sustainable fuels also carry behavioural risks. They may burn faster or slower, or contain internal impurities that can interfere with flame stability under high pressure. Even small differences in chemical composition can cause noticeable changes in engine behaviour, particularly at high temperatures and across different engine mappings.
Finally, the economic scale of the investment should not be underestimated. Many insiders have been surprised by the associated costs, pointing out that prices have exceeded initial expectations.
F1 2026: tyres, another major unknown in an enigmatic season
Tyres will also change for the upcoming season. Pirelli will introduce a new range characterised by reduced dimensions compared to the past. The wheels will remain 18 inches in diameter, but the contact patch will be reduced by 25 mm at the front and 30 mm at the rear.
Mario Isola, speaking to Motorsport, clearly explained the scale of the impact that active aerodynamic profiles will have on tyre behaviour. “We had to study maximum straight-line speeds, which will be higher, and the variations in aerodynamic load with the wings open or closed to understand the stresses the tyres will face, especially considering the overall reduction in downforce,” the Milan-based Pirelli executive explained.
“For us, everything starts from Straight Line Mode. The importance of power units is clear, particularly due to the different ways energy is deployed, but what will really make the difference for us are the wings being open or closed, because we will experience two very different situations,” Mario Isola added.
The same interview also highlighted a particularly delicate issue. Pirelli works closely with the teams to receive estimates of the load values expected by the end of the season, allowing the company to prepare tyres suited to those conditions. However, with a regulatory overhaul affecting so many areas simultaneously, obtaining precise estimates is extremely difficult.
Last year, teams used mule cars during several Pirelli-organised test days to explore load conditions similar to those drivers are expected to experience this season. Nevertheless, these remain estimates and are not directly comparable to the values anticipated by the end of 2026.
As a result, teams may struggle to hit the correct performance window with the new tyres, which will inevitably be produced based on overestimated assumptions. Pirelli has worked to increase the performance gaps between different compounds, a point confirmed by Mario Isola himself. Based on the data received, he estimated differences of up to 20 percent between teams. These figures date back to last June and should therefore be treated with extreme caution.
The countdown to the first collective test session, scheduled for 26 January in Barcelona, is now well underway. Before that, however, another key milestone awaits: the presentation of the Ferrari 678 on 23 January.
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