Formula 1 teams being allowed to run non-homologated fuels in pre-season testing that would be illegal on race weekends has been a subject of intrigue in recent weeks.
The permission to do so originated in an unintended ambiguity in the regulations that was ultimately considered a pragmatic approach, given the complexity of introducing advanced sustainable fuels in 2026.
Reports that the Petronas fuel used by Mercedes and its customers has not yet been certified and the implication it was illegal led to team principal Toto Wolff angrily denouncing such suggestions as "nonsense" when asked by The Race about them during Thursday's press conference.
It’s understood that the fuel being used by Mercedes is the advanced sustainable blend that is intended for racing throughout the season, but like most, if not all, fuel suppliers in testing, Petronas is running what is called a ‘surrogate’ fuel.
In simple terms, this is a fuel that is mixed to the recipe of the race fuel, but with the allowance for components used in it to be sourced outside of the intended sustainable supply chain. This will not be permitted after testing is complete this year, or in the future.
While the FIA does not know what fuels are being run in testing given this freedom, meaning competitors can run any fuel they want, it would be illogical to run an unrepresentative blend. But this measure allows for any problems in producing the prodigious amount of fuel needed for pre-season testing to be worked around, and could perhaps also mean a reduction in costs.
FIA single-seater director Nikolas Tombazis explained that the rules were not originally conceived to allow for the use of surrogate fuels in pre-season testing, and why it was deemed pragmatic not to tighten those rules.
“The regulations, just to be clear, were not completely explicit that during testing fuel had to be certified,” said Tombazis when asked by The Race to explain the reasoning. “That was originally an oversight rather than intended.
“As it became quite clear that also the certification was quite time-consuming and complicated, rather than intervening to adjust this not-originally-intended space in the regulations, we felt it was practical and realistic to adjust for this first year to permit the usage of surrogate fuels.
“So it was not an intended hole in the regulations, it had been unintended, but with the benefit of hindsight when we got closer to the date and it became obvious that some people would need a bit of that in order to be able to be comfortable, we felt it was a pragmatic approach.”
The FIA’s intention is that, as Tombazis says, “we want people to be certified before going racing, and that’s the target”.
However, some in the F1 paddock have suggested that there could be a lag in this process given its complexity.
Effectively, this could create a situation where the fuel supplier has completed its part of the process, but the final rubber-stamping depends on the completion of auditing by the specialist company, Zemo, that oversees the certification process.
This would mean there’s no prospect of any suppliers not having a fuel to race in Australia, but the FIA is anyway adamant its intention is for certification to be complete by the Australian Grand Prix.
“I don't think I should comment on who is fully certified or not, because that is for each fuel supplier,” said Tombazis.
“It is fair to say the new process is more complicated than what it has normally been, because not only do we look after the chemistry of the fuels, meaning we don't want to have more than a certain percentage of particular chemicals and certain combustion properties and certain energy content properties, [but] in addition to that, we have all the sustainability requirements for fuel. Each fuel has to be sustainable, and it has to achieve a certain reduction of greenhouse gas emissions. That’s a core part of this formula.
“Each fuel contains maybe 100 different components, different elements that go into the final blend of the fuel. In order to be sure that this fuel is sustainable, we need to check every component. That means to check the suppliers of these components, because they are not all necessarily made in a particular single factory. We need to check that each one of these suppliers uses methods that are reducing the carbon footprint and not originating from fossil components.
“All of that process is quite complicated, and we are learning from it. We have of course the support of Zemo, a certifying company for that. As a result, it has been a bit of a challenge.”
Five companies will supply fuel to teams in F1 this year - Petronas (Mercedes teams), Shell (Ferrari teams), ExxonMobil (Red Bull teams), Aramco (Aston Martin-Honda) and BP (Audi).
