A Pathway to climate neutrality for road transport

We bring industry actors together across the fuel and automotive value chain, offering a platform that bridges technical and regulatory expertise.

Who we are

The Working Group on Monitoring Methodologies of CO₂-Neutral Fuels (WGMM) brings together a voluntary coalition of stakeholders from across the automotive value chain – feedstock to end-users – which includes fuel manufacturers and suppliers, vehicle manufacturers and their supply chain, logistics and distribution, and the retail sector, including equipment and marketing.

Objectives

Our goal is to define a new EU vehicle class using CO₂-Neutral Fuels, as was agreed by regulators in the emission standards for light-duty vehicles (2023) and heavy-duty vehicles (2024). Our 2024 Technical Report is the source for our technical engagement and advocacy outreach in Member States and at the EU level. We aim to become the go-to partner on the regulatory landscape of CO₂-Neutral Fuels.

Activities

The WGMM generates visibility through events, publications and meetings with public officials and relevant stakeholders. The Working Group is composed of a Steering Group, a Technical Subgroup (SG1), and a Regulatory Subgroup (SG2), supported by a Secretariat, and compliance lawyers. Members meet regularly to discuss common issues and prepare the group’s activities and outcomes.

Eleven Monitoring Methodologies

Option 1: Mechanical Adaptation of Tank Filler / Nozzle

This Option ensures a dedicated connection between the filling station and the vehicle, preventing misfuelling by using specific nozzles that are incompatible with fossil fuel receptacles. However, for a complete monitoring system, this method must be paired with an upstream verification process to ensure the correct fuel reaches the station, is stored properly, and is dispensed correctly (like for example a certification scheme). The system varies based on fuel type. For liquid fuels, such as Diesel and gasoline- standardised nozzle spouts with different diameters are used. For gaseous fuels, where a leakproof connection is required, specific interface connector geometries are standardised for the different gas types (e.g. CNG, LPG, H2).

Download the Option 1 One-Pager here.

Option 2: Fuel Marker along Upstream and Downstream

The use of a CO₂-Neutral Fuels fuel marker additive, a chemical additive that is added to fuels to make them identifiable, often used to combat irregularities allows market participants to introduce climate-neutral fuel with two safety features—colour and a chemical identifier tag. This system requires minimal effort, enabling rapid implementation and flexibility for introduction within a short delay. Tested in previous projects, fuel markers help identify CO₂-Neutral Fuels liquid fuel products, which are easy to dispense and may include additional labelling. As synthetic fuels can be drop-in alternatives to fossil fuels, they share similar chemical compositions and have no adverse impact on vehicle emissions. However, this technology is not suitable for gaseous fuels. The system must be combined with a vehicle or gas station sensor to ensure compliance.

Download the Option 2 One-Pager here.

Option 3: 100% Digital Fuel Tracking System from Upstream to Downstream (DFTS w/ Digital Handshake)

Digital twins are already used in other industrial systems, and their application in fuels offers secure digital tracking and ledger accounting of CO₂-neutral fuel across the fuel supply system and in-vehicle operation. DFTS allows fast onboarding by utilizing existing data from the RED II framework in fuel supply infrastructure and vehicles. It digitalizes the entire fuel supply chain, from production to the end consumer, enabling stakeholders to utilize CO₂-Neutral Fuels as a new fuel variant with digital certification. DFTS tracks CO₂ and certifies sustainability reports along the supply chain, pairing the vehicle with the fuel supply through a digital handshake. It also incorporates a fuelling monitor in the vehicle, confirms CO₂-Neutral Fuels use for CNF-only vehicles, and ensures robustness with plausibility checks.

Download the Option 3 One-Pager here.

Option 4: Hybrid Approach: Upstream: Fuel Marker & Sensor until EU Border / Downstream: Digital Fuel Tracking System (DFTS) with Digital Handshake

The „Triple Solution“ enables market participants to introduce climate-neutral fuel by combining two safety features and a digital solution with minimal effort and maximum speed. The physical features, currently active in field tests, are colour and a chemical tag. This marking system includes CO₂ tracking and certification for CO₂ neutral fuel along the supply chain, from the fuel depot to the filling station, and a digital refuelling monitor in the vehicle. The vehicle performs a digital handshake with the petrol station to confirm the refuelling event. If the fuel is not CO₂-neutral, the vehicle reacts accordingly. It is important to note that this technology is unsuitable for gaseous fuels.

Download the Option 4 One-Pager here.

Option 5: On-Board Fuel Detection Function

A fuel detection function could be based on the existing vehicle and engine system technology without new sensors or interfaces. It is based on the difference in physical properties between regular, fossil fuels and future, Carbon-Neutral Fuels (CNF). With this function, it is also possible to alter engine operation when a non-carbon-neutral fuel is used. It could be implemented without requiring further data connections or services in a data cloud. This would protect the owner’s data privacy while being resilient against cyber-attacks, IT fraud and tampering. This detection function could be easily integrated in new vehicles or even be implemented on existing vehicles in the market. In cases where CNF is chemically identical to fossil fuel, e.g. Compressed Natural Gas (CNG), the proposed detection methodology may be limited.

Download the Option 5 One-Pager here.

Option 6: Vehicle on-board fuel molecular sensor

This option employs a single, advanced Near-Infrared (NIR) spectroscopy sensor, which provides precision akin to a „DNA fingerprint“ by scanning thousands of molecules in the fuel, accurately identifying its molecular structure. NIR technology allows for detailed and reliable differentiation of CO₂-neutral fuels, far beyond what traditional physical properties like viscosity or density can reveal. It can be seamlessly integrated with regulatory geofencing systems, enabling the application of constraints based on the vehicle’s location, further enhancing its versatility and adaptability. This technology is not suitable for gaseous fuels and molecular identical fuels like eFuels.

Download the Option 6 One-Pager here.

Option 7: Bidirectional Communication between Vehicle and Filling Station

The option targets two main aspects using Near Field Communication (NFC), Bluetooth Low Energy (BLE), or Wi-Fi: How to generate trust in the CO₂ neutral fuel (CO₂-neutral fuels) delivering partner? How to ensure that no manipulation takes place during the whole fuel transfer duration (anti-tampering)? This solution contains an authentication method of the CO₂-Neutral Fuels delivering partner before the start of fuel transfer and tampering protection during the fuel transfer. For the authentication of the delivering partner, at least one needs an internet connection to an authentication authority, which provides a digital authentication service accessible via the internet. Additionally, digital communication between the two partners is necessary. Data communication between the filling nozzle and the filler neck in the vehicle is used to initiate the authentication process and to ensure robustness against tampering during the refilling process.

Download the Option 7 One-Pager here.

Option 8: EU Market Exclusively Supplied with CO₂-neutral fuels

This option explores the potential of a full CO₂-neutral fuel market after 2035 in EU-27. Fossil-based liquid and gaseous road transport fuels would be banned and therefore unavailable in the EU for some or all vehicle categories. All affected vehicles would have to use CO₂-neutral fuels. When crossing the borders (entry) into the EU, suitable measures may still be defined. This framework must be set by political decision makers. This option assumes that CO₂-Neutral Fuels availability would be sufficient to meet demand.

Download the Option 8 One-Pager here.

Option 9: Mass-Balanced CO₂-Neutral Fuels Supply to Each CO₂-Neutral Fuels Vehicle

Mass-balancing is one of the simplest ways of tracking CO₂-Neutral Fuels (CO₂-NEUTRAL FUELS). The advantage is that an existing infrastructure can be used without adaption at gas filling stations or vehicles. The CO₂-Neutral Fuels requirements of the vehicle would be delivered via the current fuel infrastructure of fossil fuels. The fuel requirements of the vehicle are exactly matched with the same quantity of CO₂-Neutral Fuels supplied into the overall fuel supply system (e.g. a pipeline, terminal, or retail station) and matched with the vehicle securely with a digital system. The consumption of CO₂-Neutral Fuels vehicles can be met by statistical values (average mileage) or digital tracking (submitting mileage).

Download the Option 9 One-Pager here.

Option 10: Fuel Usage Balancing (FUB)

FUB tracks every fuelling event directly at the individual vehicle level and matches these amounts with certified CO₂-Neutral Fuels volumes in the cloud. The reported fuelling amounts and corresponding certificates are recorded and voided in a Union-wide Data Base (UDB), ensuring transparency and accountability. If a vehicle falls short of meeting regulatory CO₂-Neutral Fuels requirements, the onboard FUB device can trigger a wide range of inducement actions to ensure compliance. This creates a robust, transparent system that guarantees carbon accountability without the need to physically trace individual fuel molecules (mass balancing). While physical tracking offers conceptual clarity, mass balancing achieves the same end goal — verifiable carbon neutrality — while offering a crucial advantage: it removes CO₂-neutral fuels-specific infrastructure availability as a barrier. By decoupling carbon compliance from the physical fuel path, mass balancing unlocks the entire existing fuelling network immediately, allows CO₂-Neutral Fuels to scale fast, and ensures drivers can refuel anywhere without disruption.

Download the Option 10 One-Pager here.

Option 11: Combines – Upstream: Mass Balancing – Downstream: DFTS with Digital Handshake

This Option works together with a mass balancing methodology (method 9) by combining it with a digital fuel tracking system (method 3), which is required when the renewable fuel is distributed through a grid, like for example bioCNG. Under this system, customers who opt for CO₂-Neutral Fuels are guaranteed that an equivalent amount of CO₂ neutral fuel is supplied to the market and consumed in Europe, aligning with the principles of sustainability and environmental responsibility based on the Renewable Energy Directive (Directive (EU) 2023/2413) approved certification schemes. This method emphasizes the importance of digital tracking to maintain the integrity of the CO₂ neutral fuel claims.

Download the Option 11 One-Pager here.

Our 2025/2026 Summary Report on Feedstock Availability

Europe’s sustainable feedstock base could be sufficient to supply CO₂‑neutral fuels for all transport modes. This summary report outlines key findings on feedstock types, potential supply up to 2050, and the synergies between road, aviation, and maritime fuel decarbonisation.