F1 Fuel and Engine Oil Specifications for 2026

The fuel that runs through a 2026 Formula 1 power unit is one of the most tightly specified liquids in motorsport. Article 16 of the Technical Regulations sets out a comprehensive framework covering the fuel’s chemical composition, physical properties, production origin, approval process, and in-competition sampling procedure. The same article governs engine oil with equivalent precision. Together, these specifications represent the detailed regulatory expression of Formula 1’s commitment to 100% non-fossil sustainable fuel, while also establishing the performance envelope within which fuel and lubricant suppliers compete.

Fuel Specification Requirements

The Physical Properties Envelope

Article 16.3 defines the physical property limits for permitted fuel. The octane rating range is set between RON 95 minimum and RON 102 maximum, with a sensitivity (the difference between RON and MON) capped at 15.0. The lower heating value, which determines how much energy the fuel releases per unit mass, must fall between 38.0 and 41.0 MJ/kg. Density at 15°C is bounded between 720 and 785 kg per cubic metre.

The oxygen content specification is particularly significant for 2026: the regulations require a narrow window of 6.70 to 7.10 weight percent oxygen in the fuel. This is a high oxygen content for a petrol-type fuel, and it is directly connected to the sustainable fuel requirement. The molecular structures used to achieve the mandated non-fossil carbon content in the fuel tend to be oxygenated compounds, and the oxygen window reflects the compositions that result from blending sustainable components to the required concentration. Benzene is capped at 1 weight percent, sulphur at 10 mg/kg, and lead at 5 mg per litre, making this a very clean-burning fuel by any automotive standard.

Permitted Composition and Oxygenates

Article 16.4 sets the compositional limits. Aromatics are restricted to a maximum of 40 weight percent. Olefins are capped at 17 weight percent. Total diolefins must not exceed 0.1 weight percent, and the combined content of styrene and its alkyl derivatives is similarly capped at 0.1 weight percent. These compositional limits shape the molecular architecture of compliant fuels and influence how fuel suppliers approach their blend design.

The only oxygenate species permitted in the fuel are paraffinic monoalcohols and paraffinic monoethers, both subject to a final boiling point below 210°C. This provision limits which sustainable feedstocks and synthesis routes can be used in the final blend, since some sustainable fuel production pathways generate higher boiling point oxygenated species that would fall outside the permitted window. A non-sustainable additive package is permitted up to a maximum of 1.0% mass by mass, acknowledging that conventional performance additives such as lubricity improvers and deposit inhibitors remain part of the fuel formulation even where the base fuel is fully sustainable. The approved fuel article covers the full detail of the 2026 sustainable fuel requirement including the production pathways that generate the feedstocks used in compliant blends.

The Approval Process

No fuel may be used in competition without prior written FIA approval. Article 16.5 sets out the approval procedure: the fuel supplier submits two five-litre samples of each fuel they intend to supply to the FIA’s designated laboratory, accompanied by a certification of greenhouse gas reduction relative to fossil-derived petrol calculated according to the EU Renewable Energy Directive methodology. The fuel must also pass a compatibility test with the fuel bladder material specified in the safety regulations, since some aggressive fuel compositions can degrade bladder integrity over time.

During competition, the FIA takes samples from the car’s fuel system and analyses them using gas chromatography, comparing the sample’s chemical fingerprint against the pre-approved fuel. The density of the sampled fuel must be within 0.15% of the figure from the pre-approval sample. Peaks in the chromatograph showing variation greater than 12% from the approved reference are grounds for a finding of non-compliance. This sampling regime is part of how the FIA enforces the sustainable fuel requirement: the chromatographic profile of a 100% non-fossil fuel differs from that of a fossil-derived petrol in ways that are detectable by the analytical equipment. The 2026 power unit guide covers how the fuel flow limit connects to the fuel specification and energy management strategy.

Engine Oil Specifications

Physical Properties and Composition

Article 16.8 specifies the physical properties that engine oil must meet. The minimum kinematic viscosity at 100°C is 2.8 centistokes. The high-temperature high-shear viscosity at 150°C under a shear rate of one million inverse seconds must be at least 1.4 millipascal-seconds. The initial boiling point must be at least 210°C and the flashpoint at least 93°C. These specifications ensure the oil maintains adequate lubricating film thickness under the thermal and mechanical conditions inside a 2026 Formula 1 engine, where temperatures, pressures, and shear rates substantially exceed those in road car applications.

The permitted composition for engine oil covers Group I through Group V base stocks combined with performance additive packages. Organometallic petrol additives and octane-boosting additives are prohibited, preventing manufacturers from using the oil route to enhance combustion performance beyond what the fuel specification permits. Compounds with a boiling point below 210°C are limited to a maximum of 0.5% mass by mass in the final oil formulation, which addresses the risk of volatile oil fractions entering the combustion chamber and affecting the fuel’s effective composition as measured during sampling.

Approval and Used Oil Recovery

Like fuel, engine oil requires FIA approval before use in competition. The approval process requires submission of two one-litre samples to the FIA laboratory, accompanied by a complete compositional declaration. In-competition monitoring uses Fourier-transform infrared spectroscopy to compare used oil samples against the approved reference. This technique can detect the introduction of unapproved additive species that might affect combustion or lubrication performance in ways the regulations do not permit.

Article 16 also requires that all used engine oil from race weekend activities be collected and retained for potential inspection, and ultimately directed toward recycling or approved disposal routes rather than being discarded. This provision reflects the same sustainability direction built into the fuel regulations and ensures that the environmental management of waste lubricants from Formula 1 events is handled to a defined standard across all teams and at all circuits on the calendar.