Five out of 13 cars tested in the latest tranche of Australia's Real-World Testing Program recorded on-road fuel consumption levels between 9 per cent and 20 per cent higher than in their laboratory test results.
And four vehicles' on-road emissions exceeded relevant Australian regulatory lab limits for either oxides of nitrogen (NOx) or carbon monoxide.
The Real-World Testing Program compares vehicles' fuel consumption and emissions in Australian driving conditions with the laboratory test results reported by car manufacturers. The $14 million program, launched last October, is funded by the Commonwealth Government and conducted by the AAA.
Second tranche results released today cover a mix of small and medium SUVs, passenger cars and people movers.
Among the 13 vehicles tested, seven delivered fuel consumption within 5 per cent of lab test results, while five exceeded their lab test fuel consumption by between 9 and 20 per cent.
The largest variation was recorded in the BMW X3, which consumed 20 per cent more fuel in the real-world test than in the laboratory test reported by the manufacturer.
The MG3, a small car, consumed 19 per cent more fuel on the road than in the laboratory, while the Audi Q5's fuel consumption exceeded its corresponding lab test by 17 per cent, the Toyota Yaris Cross by 12 per cent, and the Volvo XC40 by 9 per cent.
However, the Kia Carnival was more fuel efficient in the real world than reported in the lab test - recording 7 per cent lower fuel consumption.
Four vehicles recorded pollutant results that exceeded Australian regulatory limits for lab tests. Three exceeded the limits for oxides of nitrogen (NOx) – the Kia Carnival, the Hyundai Staria and the Kia Sportage. The MG3's on-road carbon monoxide emissions were 85 per cent higher than the regulated lab test limit.
AAA Managing Director Michael Bradley said Real-World Testing offered consumers and fleet buyers a clear picture of vehicle running costs and environmental performance and would drive down demand for models that over-promised and under-delivered.
"Australian families and fleet buyers can place their faith in the reliability of these tests, which show that when comparing vehicles, consumers cannot assume that better lab performance will translate into real-world savings,'' Mr Bradley said.
"Using these fuel consumption test results will improve motoring affordability for Australians, while cleaning up our light vehicle fleet.
"This information could help a new car buyer save hundreds of dollars a year. The program is also helping fleet-owners to better manage their purchasing decisions, budgets, and environmental commitments.
"The AAA is pleased to be partnering with the Government to deliver this important program and is grateful that it enjoys bi-partisan political support."
Testing in and around Geelong complies with strict guidelines based on European Union legislation and developed in consultation with Australian regulators and industry. This ensures fuel consumption and CO2 results are repeatable and minimises the influence of human factors such as driving style and changing traffic flows. For research purposes, the AAA undertook 23 tests on the Program's reference vehicle (a Toyota RAV4). Fuel consumption results across these tests had less than 2.5 per cent variability.
The four-year program will test 200 cars, SUVs and utes, including electric vehicles.
The AAA first proposed an Australian-specific Real-World Testing Program in the wake of the 2015 Volkswagen emissions scandal, which showed that emissions regulations around the world were incentivising carmakers to optimise their vehicles' fuel consumption and emissions performance for the laboratory tests being used for regulatory compliance.
Since then, international studies have highlighted large gaps between laboratory and real-world performance of new vehicles. A 2017 AAA study of 30 popular light vehicles found that on average they consumed 23 per cent more fuel in real-world conditions than in laboratory tests. In addition, the real-world results achieved by 11 of the 12 diesel vehicles tested exceeded regulatory laboratory noxious emissions limits.
