The truth about fuel use: The cars furthest from efficiency ratings include the Chery Omoda 5, GWM Haval Jolion, Suzuki Swift, Audi A3 and BMW X3 but what's the solution? | Analysis

The real world fuel efficiency of cars has long been in question, with owners and road tests repeatedly finding huge chasms between ratings used in advertising and what happens on the road. 

To help combat the mystery surrounding litres per 100km and grams of CO2 per kilometre, the Australian Automobile Association secured $14 million worth of funding from the government to run 200 cars through a standardised, real-world consumption test. 

The 93km route starts in Geelong and takes in urban, rural and motorway sections. Conducted on open roads in varied conditions (though nothing catastrophic), the AAA’s team was able to complete the set course in a Toyota RAV4 control vehicle 23 times with a variance of 2.5 per cent in the fuel efficiency figures. 

Some of the results are concerning, with a number of the 70 cars tested so far using over 30 per cent more fuel than their rating in the ADR combined fuel efficiency cycle. 

We’ve taken a closer look at all the data available to highlight the most significant differences — both positive and negative — from the fuel consumption and CO2 emissions ratings.

The five furthest above their ratings

The Chery Omoda 5 BX and GWM Haval Jolion hybrid were the two furthest from their ratings at 32 per cent above for fuel consumption. Both car’s CO2 emissions were 27 per cent and 31 per cent higher, respectively. 

For the Chery and Haval, this closely mirrors CarsGuide’s experience. A recent test of the Omoda 5 EX saw 10.4L/100km, while the GWM Haval Jolion hybrid hit 7.0L/100km on test.

2025 GWM Haval Jolion Ultra Hybrid (Image: Sam Rawlings)

Next comes the Suzuki Swift. Though it is the previous-generation model, it still gives an insight for those looking at used vehicles, or perhaps discounted models in stock. Its small engine without hybrid assistance struggled on the faster motorway section.

Then it was a surprise pair of premium models, the Audi A3 and BMW X3, both are fitted with the sort of 2.0-litre turbo petrol engines engineered to give six-cylinder power outputs while dodging tight emissions standards.

2023 Audi A3 Sportback

The five furthest below their ratings 

There were a great deal more cars above their official ratings than below, which shows the limitations of lab tests. 

The furthest under its rating was the Volkswagen Tiguan, which uses a 1.4-litre turbo-petrol four-cylinder and seven-speed dual-clutch automatic. Another surprise was the Kia Cerato 2.0-litre petrol, which beat its rating by 8.0 per cent. 

The other three in the top five scraped in by less, registering marginal 3.0 per cent improvements on their rated figures, with the MG HS, Audi Q3 1.4-litre turbo-petrol and Hyundai Tucson matched by the Subaru Forester. 

2024 Volkswagen Tiguan 110TSI (Image: James Cleary)

What the results tell us

Of the 67 models tested, 27 — or about 40 per cent — exceeded their lab test results by more than 5.0 per cent, while 37 per cent were within 5.0 per cent above or below and only three were more than 5.0 per cent under the lab numbers. 

Funnily enough, the results published so far showed larger vehicles, including diesel utes such as the Toyota HiLux and large SUVs such as the Ford Everest, generally came closer to their lab test results in the real world. 

The AAA’s testing proves what we’ve all known for some time: published ADR fuel efficiency figures are probably optimistic and should be treated as a guide, not the truth. We need a more accurate model. 

2025 Toyota HiLux SR5 V-Active (Image: Mark Oastler)

One possible remedy is transitioning from New European Driving Cycle (NEDC) based figures to World harmonised Light vehicle Testing Procedure (WLTP) used in Europe and many other regions. 

The protocol, adopted broadly in 2018, is almost twice as long with higher average speeds, no fixed gear change points and greater focus on how equipment affects different trim levels. But Australian driving conditions differ greatly to the Euro-centric WLTP results, so this isn’t a perfect solution though it would make complying cars locally easier. 

Continue scrolling to read a full list of the cars tested so far.

AAA Real World Fuel Efficiency Results