F1's hidden fuel war: the 'boring' topic that could define its new era

Fuel has long been the dullest part of Formula 1’s technical landscape, a silent constant that rarely merited more than a line in a press release. But that’s about to change.

The championship’s technical reset this year has been framed largely around aerodynamics and the new hybrid architecture, but the quiet revolution sits inside the combustion chambers.

The mandate for 100% advanced sustainable fuel, derived from non-fossil feedstocks and compatible with the most complex internal combustion engines in racing, represents one of the most ambitious energy transitions in motor sport history.

It is a leap that requires not just new engineering but new chemistry, new economics and, in some cases, new industrial partnerships.

Given the impact the new fuels can have on engine performance, the specifics of each team’s 2026 fuel remain tightly protected, with suppliers treating their blends as competitive assets.

Manufacturers have no incentive to reveal the nuances of combustion concepts still in development, but enough is public to build a clear picture of the philosophies, the alliances and the pressures shaping the 2026 fuel race, and of the uncertainties that will only come into focus in the final months before next season.

This is the hidden front of the 2026 reset. And it may turn out to be the most decisive. It also comes with a raft of technical terms, which we’ve explained in more detail with footnotes at the bottom of the page.

A new combustive era

The FIA’s new rules require every team to run on a fully sustainable, fully non-fossil fuel. These fuels must be ‘drop-in’: chemically compatible with existing infrastructure and combustion systems.

They must be produced from waste biomass (eg waste vegetable oil that has already been used and is no longer fit for human consumption), captured carbon, or synthetic processes and, critically, they must run efficiently within a power unit that will rely far more heavily on electrical power in 2026, with the MGU-K¹ output rising from 120kW to 350kW. (the equivalent of 161bhp to 469bhp)

The FIA’s ambition to show the global transport industry that synthetic and waste-derived fuels can perform at the highest level has shaped the entire 2026 fuel development process.

The challenge is not to be underestimated: sustainable fuels typically have lower energy density than fossil-derived gasoline. Without careful formulation, combustion speed drops and thermal efficiency² collapses.

For a 2026 engine, where energy-flow limits take precedence over traditional fuel-flow restrictions, any loss in energy content or combustion stability becomes a direct performance handicap on track.

Higher up the racing ladder, the FIA’s feeder categories have already begun the transition: both the FIA Formula 2 and Formula 3 championships have run on 100% sustainable fuel, supplied under a single contract for all teams. While this doesn’t differentiate between manufacturers, it has given engineers and regulators valuable early data on combustion characteristics, logistics and certification that feed into F1’s 2026 plans.

Suppliers now face the task of recreating the characteristics of fossil fuel using feedstocks that behave nothing like it.

The result is a chemistry arms race unfolding quietly in laboratories.

Energy density vs sustainability

Fossil fuel became the global standard not by accident but because it delivers high energy density, consistent volatility, excellent cold-start behaviour and predictable combustion across a broad temperature range.

Sustainable fuels, by contrast, begin life with disadvantages that technicians must reverse-engineer away.

Every permitted feedstock – whether waste biomass, alcohol-to-jet derivatives, synthetic hydrocarbons or carbon-capture-based RFNBO (Renewable Fuel of Non-Biological Origin) fuels – produces molecules that do not behave like conventional gasoline.

Their molecular chains can burn too slowly or too quickly, contain higher oxygen content, or introduce impurities that disrupt flame fronts in a high-pressure combustion chamber.

The 2026 power unit’s extreme reliance on electrical deployment only sharpens the problem.

With the MGU-K providing half of the total output, the internal combustion engine must operate with near-perfect thermal efficiency to stay competitive. Any shift in knock resistance, ignition timing, or charge cooling has an outsized effect on laptime.

Sustainable fuels are vastly more expensive to produce than fossil gasoline

This creates a technical tug-of-war with no easy solution for the engineers: Increase sustainability and the energy density tends to fall. Improve energy density and the synthesis process becomes more complex, expensive, or harder to certify.

Even batch-to-batch variation becomes a strategic risk, as a fuel that burns a few degrees hotter can throw off an entire engine map.

Unlike aerodynamics, which can be corrected over time, combustion chemistry is unforgiving: once the fuel is homologated, its characteristics are effectively locked in.

Behind the scenes, suppliers are chasing purity, consistency and stability as aggressively as outright energy content. The goal is to make a non-fossil molecule behave like a fossil one. Achieving that at laboratory scale is difficult enough, but achieving it at industrial scale is the real test.

Economics: The quiet crisis

The technical challenge is significant, but the economic challenge may be even larger, and it’s the one nobody in the paddock has discussed publicly at length.

Sustainable fuels, whether bio-derived or synthetic, are vastly more expensive to produce than fossil gasoline.

The processes involved — gasification³, Fischer-Tropsch synthesis⁴, electrolysis⁵, carbon capture⁶, hydroprocessing⁷ — demand enormous energy inputs and highly specialised equipment.

Even for the largest players, scaling production to consistent, race-grade volumes is costly and logistically complex.

“What makes it so expensive is that the whole supply chain and energy contribution needs to be green,” Mercedes boss Toto Wolff said earlier this year.

“To achieve all of that, you need a certain specification of ingredients that is very expensive – and it’s coming in much more expensive than anyone thought. So we need to look at whether there’s anything we can tweak to bring the per-litre price down. We want to be open-minded.”

Suppliers are absorbing these costs because F1 offers something invaluable: a proving ground with global visibility and a regulatory framework that pushes chemistry further than most commercial markets currently require.

But none of these companies are developing 2026 fuels just for Formula 1; they are developing them for aviation, freight, and future road-transport mandates.

For F1’s partners, the championship is an influential test bench. An R&D catalyst, not a profit source.

This is why the 2026 fuels race contains a quiet economic tension. Suppliers want to treat F1 as a showcase, but teams demand consistency and performance that far exceed typical industrial tolerances.

Reconciling those expectations is expensive, and as suppliers wrestle with certification, energy-input requirements, and supply-chain uncertainty, one unspoken reality sits in the background: without substantial investment and long-term policy support, these fuels remain difficult to scale beyond niche applications.

The irony is that F1, despite its tiny fuel volumes, may be pushing its suppliers closer to commercial feasibility than any other sector. But the path from laboratory breakthrough to industrial production is long, and not every company will be able to walk it without major external forces pushing in the same direction.

What teams and suppliers are not saying

Just like with F1’s plans to be Net Zero by 2030, the move to 100% sustainable fuel has become a flagship message for the championship, but much of the real story lies in the gaps between what is said and what is deliberately left unsaid.

No supplier is revealing its exact synthesis pathway or blend composition — not because they don’t know, but because the competitive landscape is still shifting. Until fuels are homologated, every molecule is a strategic secret.

Teams, meanwhile, are staying quiet about their concerns.

The 2026 power units will be highly sensitive to combustion stability, ignition timing and charge temperature, and engineers are already modelling the risks around knock, burn-rate variability and thermal loads.

Reliable batch consistency – something taken for granted in the fossil era – becomes a performance variable again. A small difference in molecular distribution or volatility curve can alter how an engine behaves in high ambient temperatures, or how aggressively it can be mapped for qualifying.