Cars driven in Australia use up to 20% more petrol than manufacturers claim, according to a program that tests “real world” fuel efficiency on the road with laboratory calculations.
The Australian Automobile Association (AAA) test – funded by the federal government – also found four out of 13 cars tested in its latest compliance checks exceeded regulatory limits for nitrogen oxides or carbon monoxide.
Testing of passenger cars, small and medium SUVs and large people movers found that seven out of 13 vehicles delivered fuel consumption within 5% of the claims made by the manufacturers.
However, five cars exceeded the laboratory results by between 9% and 20% when tested on the road. One car performed 7% better than claimed by the manufacturer.
The testing included the average results of vehicles driven in urban and rural roads as well as roads at various speeds.
The testing took place in the Geelong region of Victoria in December 2023 in conditions that AAA said were strictly controlled and in accordance with European Union legislation that “guarantees the consumption of fuel and CO.2 results are repeatable and reduce the influence of human factors such as driving style and changing traffic flow”.
According to the auto association, the worst offenders in the second round of its testing were:
It had the biggest difference of the cars tested. AAA found that in real-world testing, the 2021 SUV model needed 8.9 liters of fuel to drive 100km – 20% more than the 7.4 liters per 100km reported by the manufacturer from a laboratory test.
The MG3 was found to use 19% more fuel than its laboratory result of 6.7 liters per 100 kilometers in tests for the 2023 model of the compact car.
Audi’s Q5 SUV was found to use 17% more gasoline than claimed, with a real-world performance result of 5.6 liters per 100 kilometers for the 2022 model compared to its lab test result of 4.8 liters.
Toyota Yaris Cross Hybrid
The Toyota Yaris Cross Hybrid used 12 percent more gasoline than the claimed efficiency of 3.8 liters per 100 kilometers, tests of its 2021 model found.
On the contrary, some cars performed better than the manufacturer claims.
Kia Carnival testing found its 2023 model used 7% less fuel on the road than its certified lab results, with AAA claiming its actual fuel efficiency was 6 liters per 100km.
Pollution from vehicles was also tested. Four of the 13 vehicles recorded pollution results that exceeded Australian regulatory limits in laboratory tests.
Three exceeded the limit for nitrogen oxides: Kia Carnival, Hyundai Staria and Kia Sportage, AAA said, while the MG3’s on-road carbon monoxide emissions were 85% higher than the regulated laboratory test limit.
AAA managing director Michael Bradley said the real-world testing program gave consumers more transparency and would “reduce demand for over-promised and under-delivered models”.
“When comparing vehicles, consumers can’t assume that best lab performance will translate into real-world savings,” Bradley said.
“This information can help a new car buyer save hundreds of dollars a year while cleaning our fleet.”
The Australian government-backed testing program was put in place after a 2015 scandal involving Volkswagen, which found the manufacturer had deliberately misled consumers who may have bought cars based on false claims of low emissions.
BMW, MG, Audi and Toyota were available for comment.
The first phase of real-world testing achieved fuel consumption rates of up to 13% higher than laboratory tests.