The technical fix for European cars implicated in the Volkswagen emissions scandal may be ineffective, according to the findings of an Italian consumer group.

Altroconsumo, which tested an Audi Q5 to analyse the effects of the fix for the affected cars offered by VW, found that after the defeat device was removed, NOx emissions were 25 percent higher than before. The fix imposed on European cars affected by the scandal currently involves a software update for 1.2 and 2.0-litre engines, while 1.6-litre units require a new flow transformer in addition to the software tweaks.

The Italian consumer group is a member of the European Consumer Organisation (BEUC), which issued a statement regarding the findings: “This is another blow for EU consumers and a new dimension of the VW scandal. This test by our Italian member clearly demonstrates that VW’s solution to deactivate the defeat device is not reliable.

“It is imperative that the German testing agency who approved the fix, but also their national counterparts, urgently re-examine the solutions to repair the affected cars and that they publish these results. Consumers need to be 100 percent certain that their car will be in conformity with emission thresholds after the recall. National public authorities must finally take action and put pressure on VW to correct their misbehaviour.”

 A spokesman for BEUC revealed that the organisation, in light of the findings, will be looking into retesting other cars that have been fixed, but also stated that the retesting of vehicles should be the responsibility of public authorities, as well as Volkswagen itself re-examining the tests it may have carried out on the vehicles, post-recall. The test results should be made public for full transparency and to give consumers a full understanding of the effects of the service action being requested, he continued.

The BEUC spokesman also criticised Volkswagen’s handling of the recall and fix. “It’s a wake-up call for Volkswagen to communicate; the information people have been getting and which has been made public is very unclear," he said. "In some states the recall is mandatory and in others it’s voluntary.

“The delays will only confuse people further, so a plan of action needs to be fully communicated more effectively.”

“If consumers are concerned about the effect of the fix upon their vehicle, they need to ask the relevant authorities if they should do the fix or not, rather than just do what VW advises them to do. A retesting procedure is necessary because they need to know that the fix is the best thing to do.”

Meanwhile, governments of countries affected by the scandal need to ramp up pressure on Volkswagen, the BEUC representative said. “It’s also a wake-up call for the governments to enforce their power upon Volkswagen; these practices can’t go on any more," he said. "The governments need to act on the behalf of the consumer.”

Autocar UK has contacted Volkswagen for a response to the group’s findings and is awaiting a reply.