DfT ordered to disclose details on emissions ‘defeat devices’

The Department for Transport (DfT) has been ordered to disclose details about how ‘defeat devices’ operate in certain vehicles.

It follows a legal complaint to the Information Commissioner’s Office (ICO) after the DfT refused to share the information in full last year. 

‘Defeat devices’, revealed in the 2015 Dieselgate scandal, affect the operation of emission control systems – switching them off or reducing their effectiveness under certain conditions. This means vehicles can be much more polluting on the road than they are in the lab.

The law currently prohibits the use of defeat device technology, subject to some limited exceptions. However, environmental group ClientEarth claim an estimated 19 million vehicles are still on roads across the UK and EU suspected of using these illegal devices. 

Last year, in response to investigations into potential illegal practices, the DfT received information from some auto manufacturers – including VW Group, Mazda and Stellantis – on which conditions affect the performance of emission controls in certain vehicle models. However, the Government refused to provide this information in full to ClientEarth.

The DfT had argued that the information was commercially sensitive and could harm the intellectual property rights of manufacturers.

In July 2023, ClientEarth challenged this position in a complaint to the ICO.  

This week, the ICO has issued a decision which supports ClientEarth’s argument that information on how vehicle engines control harmful emissions cannot be kept secret just by virtue of being commercially sensitive.  

ClientEarth lawyer Katie Nield said: “This decision makes it crystal clear that information about how and when defeat device technology is used should not be concealed by the Government for the sake of protecting industry ‘trade secrets’.”

The DfT now has 35 days to provide the information, though it has the right to appeal within 28 days.  

Nield said: “This decision is a critical step towards more transparency and effective regulation for a sector with a scandal-ridden past.

“The Government must act to lift the lid on the widespread use of dodgy emissions practices once and for all and ensure that manufacturers - not consumers - are made to foot the bill for the excessive pollution that illegal defeat devices continue to cause.”