Plug-in hybrids (PHEVs) on average emit 3.5 times more CO2 than in laboratory testing, according to data from the European Commission.
That equates to 4L/100km or 100g CO2/km more than their official WLTP test values. That means their real-world CO2 emissions were only 23 per cent lower than for conventional cars.
The European Commission warns PHEVs “are currently not realising their potential, largely because they are not being charged and driven fully electrically as frequently as assumed”.
The data has also revealed petrol and diesel vehicles’ CO2 emissions were higher than their official claims – by 23.7 per cent for petrol cars and 18.1 per cent for diesel cars.
It says such a discrepancy was to be expected, and the gap is half as wide as comparing real-world emissions and claims under the old NEDC test standard.
The European Commission has released the first data from a sample of 617,194 cars, representing 7.2 per cent of cars first registered in 2021. The data also includes 6667 vans.
A further 288,231 vehicles were filtered out for various reasons such as having mileage of under 500km.
You can access the full dataset here, and the Commission’s report here.
The data has been gathered from on-board fuel consumption monitoring (OBFCM) devices, which have been required since January 2021 on all new cars and small vans and also record vehicles’ energy consumption and mileage.
This data is collected by carmakers and sent annually to the Commission, which received its first set of data in April 2022. It’s this 2021 data that has been released in the inaugural report.
The body says it will continue monitoring this gap between real-world and claim figures as it collects more data, as one year’s worth of data isn’t enough to be able to achieve an adequate analysis.
It says it will assess whether further steps should be taken to avoid it growing further such as adjusting the WLTP standard, which was introduced in 2017.
It has confirmed it will introduce changes from 2025 on how it calculates PHEVs’ utility factor, or the expected share of distance driven electrically.
The European Commission says it expected a gap given laboratory testing can’t fully replicate real-world factors such as traffic and road conditions, landscape, ambient temperature, use of air-conditioning and electronics, and driver behaviour.
It called out the poor coverage of the 2021 vehicle fleet, with most manufacturers reporting data for less than five per cent of their vehicles first registered that year.
Companies like JLR (43 per cent), Ford (34 per cent), Mercedes-Benz (27 per cent) and Volvo (24 per cent) supplied much more data.
The European Commission says road transport is responsible for around one fifth of the European Union’s total greenhouse gas emissions, and within this light-duty vehicles – i.e. passenger cars and light commercial vehicles – are responsible for around 70 per cent of the total.
The European Union is set to ban the sale of new petrol and diesel cars by 2035, including plug-in hybrids.
Electric vehicle demand has cooled of late in Europe, while PHEVs have maintained their market share – and in February, they even recorded a higher rate of growth than EVs.
Compared to February 2023, EV sales in the EU were up nine per cent, while PHEV sales were up 11.6 per cent.
EVs nevertheless outsell PHEVs in Europe. In February, they held a market share of 12 per cent, compared with 7.3 per cent for PHEVs.
Conventional hybrids beat them both, with 28.9 per cent market share. Their sales were also up by 24.7 per cent.
Some companies, including Bentley and Aston Martin, have chosen to delay upcoming EVs to prioritise PHEVs instead.
