Volkswagen Dieselgate fix found to impact fuel economy

Autocar has accused Volkswagen of bungling the fix for models affected by the Dieselgate emissions cheating scandal by issuing a technical 'cure' that actually increases fuel consumption.

Carrying out real-world tests on a 2013 Volkswagen Touran (not sold in Australia) fitted with the EA189 1.6-litre diesel engine, researchers found NOx emissions almost halved from 0.639g/km to 0.351g/km following the fix.

Unfortunately, the British magazine also found fuel economy for the Golf-based people mover fell from 5.57L/100km to 5.93L/100km - a 6.5 per cent increase in fuel use.

Globally, VW claims its fix has no impact on a car's performance or economy.

The German car maker was quick to dismiss Autocar's findings, saying that more than 20 variables in the real-world test carried out could have affected the results - although the car maker did not state to the magazine what those variables were.

In European markets Volkswagen now has fixes for the 1.2, 1.6 and 2.0-litre versions of the EA189 engine. Factor in the transmission and car combinations and this involves an incredible 750 individual fixes.

According to Autocar, some customers driving the 2.0-litre EA189 post-fix have experienced breakdowns, increased fuel consumption, reduced performance, increased smoke and more problems associated with the diesel particulate filters.

If that's not enough, others say they have suffered exhaust gas regeneration valves, turbochargers and fuel injection failures.

In response, VW says the problems are not related to the fix and could be down to poor maintenance.

In the UK alone, Autocar claims, up to 1.2 million Volkswagens are fitted with the 'defeat device' that led to the emissions scandal - so far, up to 600,000 have received the car maker's fix.