Australian new car buyers cannot trust official fuel economy figures for the vast majority of models currently tested in the field by the Australian Automobile Association (AAA).
Following its latest round of federally funded testing, Australia’s leading motoring association has now compared the actual fuel consumption and emissions of 141 new petrol, diesel and hybrid models with the official figures displayed on the window stickers of new vehicles in showrooms.
The latest results, published on realworld.org.au, show around 80 per cent of models tested could not match their window tag number, with discrepancies of up to 25 per cent.
The GWM Tank 300 petrol off-road SUV was the furthest from its official claim with a test result of 11.9 l/100 km, 25 percent above the official combined fuel consumption figure of 9.5 l/100 km.
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Previous tests have shown even larger deviations of up to 35 percent over official fuel consumption figures.
Among the diesel-powered models in recent testing was the Kia Tasman ute – the Korean brand’s first competitor to the Ford Ranger and Toyota HiLux.
The Tasman consumed four percent more fuel in the practical test, namely 8.4 l/100 km compared to the official figure of 8.1 l/100 km.
The BYD Seal and BMW iX1 were the only electric vehicles (EVs) in the final round of testing. Both fell well short of their claimed range on a single charge, with the iX1 coming in at 10% and the Seal at 25% less.
A total of 11 electric vehicles have been tested so far, with results ranging from 3.0 percent better than stated to 31 percent worse than the officially stated range.
Ironically, the Ford Mustang GT – which is equipped with a 5.0-liter V8 petrol engine – used 22 percent less fuel in real-world testing than stated on the official sticker.
Of all models tested so far, AAA found that 76 percent used more fuel and produced more emissions than indicated on the windshield stickers.
“The AAA supports the implementation of increasingly stringent vehicle emissions standards, but we also want to ensure our vehicle fleet is cleaner in the field, not just in the lab,” AAA CEO Michael Bradley said in a statement.
The latest findings follow the federal government’s first New Vehicle Efficiency Standard (NVES) report, which revealed the car brands that exceeded their emissions targets in 2025.
“By independently measuring fuel consumption and emissions performance in real-world conditions, this program provides transparency into NVES-related emissions reductions and the level of their implementation on Australian roads,” Bradley said.
Meanwhile, transport sector emissions fell 0.4 per cent in the 12 months to September 2025, part of a 3.1 per cent fall in Australia’s overall emissions over the period.
However, emissions from the transport sector were still 23 percent higher than in 2005.
Below are the fuel economy results from AAA’s latest round of real-world testing.
| vehicle | Fuel type | Entitlement to mandatory laboratory tests (l/100 km) | AAA test result (L/100 km) | inequality |
|---|---|---|---|---|
| 2026 Toyota Yaris Hybrid | petrol | 3.3 | 3.6 | +10% |
| 2026 Mercedes Benz C300 | petrol | 7.1 | 7.3 | +3% |
| 2026 Hyundai Kona | petrol | 6.6 | 6.9 | +5% |
| 2026 Honda HR-V | petrol | 6.2 | 7.4 | +19% |
| 2026 GWM Tank 300 | petrol | 9.5 | 11.9 | +25% |
| 2026 Ford Mustang EcoBoost | petrol | 9.4 | 8.8 | -6% |
| 2026 Ford Mustang GT | petrol | 13.6 | 10.7 | -22% |
| 2026 Mercedes-Benz GLE450d | Diesel | 7.4 | 6.6 | -11% |
| 2026 Kia Tasman | Diesel | 8.1 | 8.4 | +4% |
| 2026 WORLD seal | EV | 650km | 488km | -25% |
| 2026 BMW iX1 | EV | 400km | 360km | -10% |
MORE: Australia’s new emissions regulations are delivering results, says Bowen
