Australian study finds VW diesel using up to 14% more fuel in real world driving after emissions upgrade
Emissions analysis commissioned by the Australian Automobile Association (AAA) has found an affected VW diesel vehicle to be using up to 14% more diesel after being recalled for the mandated emissions system fix.
Conducted in partnership with the Fédération Internationale de l’Automobile (FIA), the real world testing was commissioned to quantify performance changes associated with the software upgrades being implemented on affected vehicles.
The recall fix was implemented by VW after 2015 when it was revealed that more than 11 million VW diesel vehicles had been sold with a defeat device installed, which detected when a vehicle’s engine was being tested and subsequently changed performance to improve emission results.
In late 2016, AAA commissioned research firm ABMARC to run two tests on an affected VW vehicle—one before recall and one immediately after.
The test result indicates that a 2010 model Euro 5 VW Golf used an average of 7% more fuel (0.5 liters/100 km) after it had the recall completed. This ranged from using 2% more fuel while driving in urban areas, 7% more fuel on rural roads and 14% while driving on highways.
The tests showed a reduction in emissions of NOx carbon monoxide and particulate matter occurred after the recall fix. However, the NOx emissions were still 4.11 times the laboratory limit after the recall when tested under real driving conditions.
The aim of the study was to determine the impact of the recall fix by comparing the real world pollutant emissions of the test vehicle to the respective laboratory limits and the fuel consumption to the official figures before and after the recall fix.
The results show that VW may have found a fix for reducing the level of noxious NOx emissions but as a result, the amount of fuel used has increased. The testing also indicated that both power and torque had increased slightly after the recall fix. The testing further supports the AAA’s call for a real-world emission testing program in Australia.
The AAA has strongly advocated for the introduction of a real-world emissions test program following its own research program, which tested 30 Australian cars, on Australian roads, using Australian fuels.
An Australian real-world test program would allow consumers to make more informed purchasing decisions, and allow policy makers to ensure that regulatory settings reflect real-world conditions.
The AAA argues that there is no point in introducing tougher vehicle emissions standards in a laboratory setting unless information on real world performance is in the hands of consumers.