Intro

The official CO₂ emissions and fuel consumption of passenger cars and vans are determined during a standardised laboratory test following the Worldwide harmonised Light-duty vehicles Test Procedure (WLTP). The WLTP is designed to represent real-world driving conditions and produce comparable results between vehicles.

As of 2021, new vehicles have to be equipped with on-board fuel consumption monitoring devices (OBFCM) to record the amount of fuel or electric energy used and distance driven in “real-world” conditions, i.e. when the vehicle is driven on the road.

Article 12 of Regulation (EU) 2019/631 setting CO₂ emission standards for cars and vans mandates the Commission to monitor the OBFCM in order to ensure that the official WLTP values remain representative of the real-world values. The real-world data has to be collected and reported by vehicle manufacturers and Member States as set out in Implementing Regulation (EU) 2021/392.

The Commission uses the reported data to calculate the “real-world gap”, which is the difference between the OBFCM values and the official WLTP values. A positive gap means that, on average, the vehicles concerned consumed more fuel and emitted more CO₂ when driven on the road than the official test results indicated. By looking at the time trends of the gap, the Commission assesses how the real-world representativeness of the WLTP is evolving.

The “Data” tab contains a visual overview of the main results for the first three years of the real-world monitoring (2021-2023). They are based on the data collected by vehicle manufacturers as of 2021 and by Member States as of 2023.

The latest dataset (“reporting year 2023”) includes the data recorded and collected by 54 manufacturers and 18 Member States throughout 2023 and reported by them in the following year. It covers new vehicles which were first registered in the EU in 2021, 2022 and 2023 (“registration year”).

After data cleaning and processing to remove outliers, the final real-world dataset used for the calculations includes 2.8 million cars and 63,000 vans first registered in 2021, 2.5 million cars and 274,000 vans first registered in 2022, and 1.2 million cars and 145,000 vans first registered in 2023.