Research casts doubts on green car emissions figures

Green cars can use four times more fuel than laboratory-controlled tests state, new research reveals.

Motorists who buy green cars risk being “ripped off” with a new study showing they can use four times more fuel than shown in laboratory-controlled tests — a finding that challenges the integrity of tighter fuel efficiency regimes aimed at meeting Australia’s Paris targets.

The Australian Automobile Association will today release results of an analysis that tested emissions levels as well as fuel consumption on Australian roads for 30 different vehicles using a portable emissions measurement system.

Results were compared with the official performance figures for the same vehicles obtained through controlled laboratory tests. The analysis showed that, on average, the “real-world” fuel consumption of all the tested vehicles on Australian roads was 23 per cent higher than what was advertised.

It also emerged that some cars could emit up to seven times the legal limit of noxious emissions than indicated by laboratory tests. Testing of 12 diesel vehicles showed that, on average, emissions of nitrogen oxides exceeded laboratory limits by 370 per cent.

AAA chief executive Michael Bradley said more stringent emissions laws were meant to reduce pollution and drive down fuel usage, but the benefit of greener technologies were largely confined to the laboratory.

“It’s becoming clear that, as emissions standards tighten, the gap between laboratory results and real-world results is widening — meaning consumers and the environment are increasingly being ripped off,” he said.

“Australian motorists have a right to accurate information about fuel consumption and environmental performance when buying a new car. The current system is misleading consumers and regulators. Only real-world testing can drive down costs to consumers and deliver meaningful environmental benefit.”

While motorists are often willing to pay an environmental premium for greener cars, the fuel consumption of one plug-in hybrid vehicle was 166 per cent higher than the level claimed when at full charge and 337 per cent higher when tested at a low charge.

The price difference between a standard-engine vehicle and its hybrid equivalent is about $4000, conservative estimates show.

The release of today’s findings coincides with the AAA’s new campaign for government to urgently introduce so-called real-world emissions testing for new cars and make the information easily available to consumers.

The discrepancy between the real-world and laboratory test results was partly attributed to increasing vehicle emissions standards.

The analysis concluded manufacturers were deploying technologies “optimised for the laboratory drive cycle”.

The discrepancy is most obvious for “Euro 6” compliant vehicles with the average real-world results being 142 per cent of the official figures claimed.

A spokeswoman for Urban Infrastructure Minister Paul Fletcher, said the ministerial forum on vehicle emissions would work through a “range of issues” that could include examining the “merits of real-world testing’’.