Why Are 4 F1 Teams Still Missing Approval for Their Fuel?
With the 2026 Formula 1 season drawing closer, attention in the paddock has begun to shift toward an unexpected area of concern. While preseason testing has offered the usual clues about performance and reliability, there is growing speculation that fuel homologation could become an early storyline, particularly for the teams running Mercedes power units.
Current rumours suggest that Petronas, the fuel supplier to Mercedes and its customer teams, is still working through the FIA certification process for its advanced sustainable fuel. If that process is not completed in time, four teams could be affected: Mercedes, McLaren, Williams and Alpine. Although no official warning has been issued, the situation has introduced a degree of uncertainty at a sensitive point in the development cycle.
The backdrop to this concern is the major regulatory shift arriving in 2026. Under the new rules, Formula 1 cars must run on fuels derived entirely from Advanced Sustainable Components. These fuels must be produced from non food biomass, municipal waste, or renewable non biological sources, while also meeting strict greenhouse gas reduction thresholds set by the FIA. The change is designed to preserve the performance DNA of Formula 1 engines while aligning the sport more closely with global decarbonisation goals.
What complicates matters is the technical and administrative depth of the homologation process. Certification, now overseen by the Zemo Partnership on behalf of the FIA, requires suppliers to demonstrate not only the sustainability of their fuel sources but also chemical consistency, energy performance and full regulatory compliance. Even for experienced suppliers, the process can be lengthy and highly detailed.
If Petronas does not secure approval before the season opening Australian Grand Prix, the Mercedes powered teams may need to rely on a temporary fuel specification. While this would keep them compliant with the regulations, it would not necessarily be ideal from a performance perspective. Modern Formula 1 power units are developed in close coordination with their fuel partners, and combustion characteristics are finely tuned over several seasons. Any late change to fuel chemistry risks disrupting efficiency, drivability and energy deployment strategies.
At this stage, teams are understood to be continuing preparations without public alarm. Preseason testing in Bahrain has provided little clarity because the use of sustainable fuel is not mandatory during testing, meaning suppliers can still be finalising their homologation work behind the scenes. That leaves the true competitive picture somewhat obscured as the opening race approaches.
Whether this becomes a genuine competitive issue will depend entirely on timing. Fuel homologation deadlines in Formula 1 often run close, and suppliers typically build contingencies into their programmes. Even so, the transition to fully sustainable fuel represents one of the most technically demanding elements of the 2026 regulations, and it is unsurprising that the paddock is watching closely.
If approval arrives in the coming weeks, the concern will likely fade into the background. If delays persist, however, four teams could find themselves starting a new regulatory era managing a variable that is usually one of the most tightly controlled elements of modern Formula 1 performance.
