Vauxhall Zafira TourerVauxhall has issued a strongly-worded statement insisting its cars do not have any emission test detection devices – despite the suggestion by BBC’s Panorama that they do.

Such ‘defeat device’ software as used by Volkswagen has been proven to detect test conditions and alter engine settings to produce fewer harmful NOx emissions than in real-world driving.

The Panorama test appeared to show a disparity between tailpipe emissions of a Vauxhall Zafira Tourer 1.6 diesel when strictly run under official test conditions and when a single parameter – the temperature of the engine – was changed.


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The engine ‘outside’ test cycle conditions produced three times the amount of NOx as the test cycle-compliant engine. This could indicate the presence of software that detects a vehicle is undergoing an emissions test.

Not so, says Vauxhall. Its products “comply with all regulatory requirements, including the in-service emissions testing program, according to EU rules. These requirements are periodically audited by the approval authority.”

Vauxhall: Panorama used a poorly-performing car

So what caused the difference in emissions found by Panorama? Either a test that wasn’t correctly set up, insists Vauxhall, or a vehicle that was not performing correctly.

“Panorama has refused to share information on the technical accuracy of the test prior to the broadcast.”

This lack of information is why Vauxhall believes the car was not performing as it should: when Panorama conducted the emissions test strictly by the book, NOx emissions were still twice as high as legislation permits.

Panorama also ran the Zafira Tourer through a regular real-world procedure, and found that NOx emissions went “off the scale” of the testing equipment.

A test engineer at the Czech Republic lab used by Panorama said that although emissions will increase in real-world driving, it should be by ‘tens of percent’.

“There is no reason for the emissions to be three times, five times, ten times higher.” Vauxhall did not respond to this observation in its statement.