The regulatory revolution of 2026 presents numerous innovations and fuels are among them. The reason is twofold, because if on the one hand the petrols must have advanced sustainability and can no longer be synthesized from fossil materials, on the other the technical regulation places emphasis on different aspects compared to the past. In fact, with the limit on the flow of energy entering the engine, the game is played above all on the density of the fuel to reduce the weight and dimensions of the car, as explained to FormulaPassion Valeria Loreti, Shell Motorsport Technology Manager.
The importance of density
Traditionally, the most important parameter of a fuel is the energy content, i.e. the chemical energy released during its combustion that can be converted into power to be transmitted to the wheels. With the old power units this value had to fall within a narrow window, with a maximum threshold also for the quantity of petrol injected into the engine at each time interval. The 2026 regulation, however, introduces a substantial changedirectly limiting the flow of chemical energy of the fuel injected into the combustion chamber.
All this changes priorities for suppliers, including Scuderia Ferrari HP partner Shell, giving greater emphasis to other parameters. “In addition to energy content, density is also important,” explains Valeria Loreti. “The bulk flow of gasoline is no longer regulated, which is why if you have little energy in a certain volume of fuel, you need more and therefore increase the weight”. The higher the energy density, however, the lower the quantity of petrol consumed for the same energy flow, thus being able to design a smaller tank, to the advantage of weight distribution and aerodynamic dimensions.
“In theory, the most disparate solutions can be created,” continues Loreti. “I think it’s the first time based on how we make the fuel, we can even bring the idea of changing the shape of the carfor example where the tank goes.” A high energy density also allows you to complete the distance of a Grand Prix with less petrol on board, reducing the weight of the car in race configuration and further reducing consumption. “The less you put in, the better”, confirms the Delivery Manager of Shell Motorsport. “There will be a limit on the flow of energy, so if I have a high energy density fuel, that’s an advantage.”
A great opportunity
Loreti underlines how the development of 2026 fuels also focuses on other aspects: “The temperatures, the combustion pressures, the stoichiometric ratio… All the parameters that define the relationship between the fuel and the engine are fundamental. As formulators, we develop these special fuels based on the chemist’s knowledge, i.e. molecules, combustion chemistry, burning rate, efficiency, etc. But then we have to complement each other with the engineer’s knowledge, because I have to understand how the differences in combustion can have an effect for him. Vice versa, I can propose a certain composition over another to optimize different parameters”.
The new engines maintain the V6 architecture of the previous generation, but, despite appearances, what happens inside them is profoundly different. The 2026 regulation prescribes different limits for the compression ratio and turbo pressure, also allowing a single spark plug ignition versus the previous five, significantly changing the combustion speed and the way it is controlled. All this forces Shell and other suppliers to review the formulation of their fuels. “Every time there is a change in the regulation and something can be changed in terms of the thermodynamics of combustion, for us it is a‘opportunity to improve and reshuffle the cards”, comments Loreti. “It’s a process of continuous exchange: the engineers share their vision, where they want to go and what parameters they want to change. From this we understand how we can start to formulate the fuel.”
New development techniques
2026 will be yet another regulatory cycle that Shell and Ferrari will face together, renewing a collaboration that has continued for 75 years. Over this period of time, development techniques for petrol have changed continuously and this occasion was no exception: “In the early 2000s, everything was done in the lab. There were some very good people with great experience who assessed by eye what to mix and then measured the parameters. 30-40 different fuel candidates were prepared and about ten, perhaps even fewer, were chosen. Those were produced in larger quantities for engine testing.”
“Now the number of tests on the engine is limited. Furthermore, having a digital model, we can choose the candidates with the greatest probability of giving maximum performance in certain aspects, optimizing one or the other parameter.” Exactly as for aerodynamics, therefore, also in the petrol field the game is played on the correlation of virtual development models. Loreti concludes: “For the fuel we have on the track, we ran over a million simulations to choose onewhich is certainly not the same as starting with 20 or 30 candidates. Even in this case, however, a validation test is carried out, because it is not certain that the model is correct. It is a continuous circle, in which this model interacts with those that Ferrari engineers develop to make predictions from their point of view.”
