WLTP fuel efficiency standards ‘failing consumers’

A new investigation into real-world fuel consumption has thrown the legitimacy of the European WLTP fuel efficiency ratings into question, with average fuel economy and emissions found to be around 20 per cent higher than official figures.

The report, released by the European Union’s First Commission, is said to have analysed as many as 600,000 vehicles’ real-world data, and the findings have shown that petrol cars were 24 per cent less efficient compared to official WLTP claims.

Diesels, meanwhile, were around 18 per cent shy of the official claims (L/100km), while the biggest offenders were plug-in hybrids (PHEVs) that emitted around three-and-a-half times the CO2 emissions, compared to WLTP claims.

In response, the EU is now set to mandate even tougher criteria for PHEVs that will be introduced as soon as 2025.

The Commission hopes that overhauling the way it formulates an overall L/100km figure will help paint a clearer picture of a PHEV’s real efficiency, representing when the vehicle will rely on its electric power or combustion engine.

Prompting the renewed scrutiny over PHEVs is evidence that most owners do not bother to recharge their vehicle anywhere near the original estimates that underpinned the WLTP figure.

Without topping up the battery, the advanced powertrain has to rely on its combustion engine and, with the added weight of the battery and electric motor to carry around, the plug-in hybrids can return poorer economy than a non-electrified vehicle.

To tackle the discrepancy between the laboratory fuel efficiency of petrol and diesel cars, the Commission announced that “further steps” were needed – a hint that the WLTP test regime would be reinvented to be both more stringent and representative to paint a more accurate picture of a car’s efficiency.

Originally introduced in 2017 following the ‘dieselgate’ scandal, the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) was designed to be indicative of what motorists would achieve in real-world driving.

However, many motorists and industry commentators have subsequently claimed the gap between lab and what’s achievable has widened.

If you’re wondering how the EU Commission managed to attain such a huge volume of real-world fuel efficiency data, since 2021 cars automatically log and store real-world fuel efficiency in their ECUs that can be downloaded by dealers.

As well as tightening up efficiency tests going forward, the Commission has also vowed to address “electric vehicle affordability” while providing sufficient charging infrastructure in all member states.

The EU also said it was working on a plan to help secure a supply of the raw materials needed to produce batteries in a bid to reduce the high cost of producing EVs.

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