A new European-wide analysis argues that in real-life driving conditions, plug-in hybrids They emit COâ‚‚ levels very close to those of a conventional gasoline or diesel passenger car. The data collected shows that the gap between laboratory and road figures is wide, with results that even estimate actual emissions. up to about five times above what was declared in homologation.
The work, led by the organization Transport & Environment and based on records of fleets registered on the continent between 2021 and 2023, concludes that the effective climate advantage of these models remains at a 19% compared to traditional cars, far from the 75% reduction often assumed on paper.
How the data was obtained and what it reveals
The research uses actual meter readings OBFCM integrated into the vehicles themselves, with a universe of analysis that covers around 800.000PHEV sold in Europe. On this basis, the comparison with the WLTP protocol shows a growing divergence: in 2021 it was around 3,5 times and in 2023 it was already approaching the threshold of five times what was announced.
The authors point to a structural problem: laboratory tests are based on overly favorable assumptions about user behavior, which amplifies the difference with everyday experience. In terms of emissions, this gap has widened over time, which reinforces the need to adjust assumptions and metrics.
Why COâ‚‚ savings fall short
The key element is the so-called utility factor, which measures what percentage of kilometers are traveled in electric mode. While the homologation assumes that electric driving covers approximately 84% of the route, the actual readings remain around 27%. Even when driving in electric mode, the combustion engine comes into operation during a considerable part of the journey.
Adding to this usability gap are design issues: relatively small batteries, higher weight of the vehicle and electric motors that require frequent use of the combustion engine when facing slopes, acceleration or long journeys. All of this means that the PHEV operates like a gasoline engine more often than expected, but carrying the ballast from a battery.
When the battery is depleted and the car goes into so-called depleted charge mode, emissions can register much higher peaks as expected from the catalogue. In load maintenance situations, the combustion engine takes on a large part of the work, producing COâ‚‚ levels similar to those of a car conventional combustion.
Daily charging is also a bottleneck: many drivers do not plug in as often as they would like due to a lack of public infrastructure, the impossibility of installing a home charging station, or the lack of fast charging for most PHEVs. The result is a low-electricity usage pattern and, therefore, a reduction in COâ‚‚ emissions. very modest.
Effects on standards and on the pocketbook
According to the report, the underestimation of emissions has allowed several large automotive groups avoid fines of COâ‚‚ for a cumulative amount of more than 5.000 billion euros between 2021 and 2023. In parallel, some manufacturers defended more lax standards, presenting PHEVs as a transition alternative in view of the objectives of zero emissions of the next decade.
Independent experts have reviewed and validated the methodology used. Researchers from the Institute Fraunhofer, for example, have highlighted that the gap between official figures and the real world is greater in PHEVs than in purely petrol or diesel vehicles, supporting the need for to correct the factors used.
For users, the gap also has an economic dimension: fuel consumption in practice can amount to about 500 Euros additional annual maintenance costs compared to what the data sheets suggest, especially when the car is used on long trips or without frequent recharging. The feeling of acquiring a "cleaner" vehicle does not always correspond to its climate impact real.
What can change from now on
The European Union is reviewing its COâ‚‚ regulatory framework at a time when there is a debate about whether to maintain exceptions for plug-in hybrids beyond 2035. Among the recommendations that emerge are recalibrating the utility factor with real-world data and accelerating the transition to plug-in hybrid vehicles. pure electric accompanied by a suitable cargo net.
For PHEV technology to deliver what it promises, design adjustments would be necessary (batteries with greater usable capacity, stricter energy management strategies) and, above all, a change of charging habits supported by reliable infrastructure. Without these elements, COâ‚‚ reductions will still be much lower than expected on paper.
The picture drawn by the evidence is clear: with current usage and existing load conditions, plug-in hybrids achieve a reduction of emissions modest and present notable differences compared to laboratory tests; a combination that impacts regulation, personal finances, and the climate strategy of transport.
