Which cars are less fuel efficient than advertised?

The 2023 Suzuki Swift used 31% more fuel on the roads than advertised for the car, according to the AAA real-world test.
real-world test car

A real-world test has found which cars are less fuel efficient than advertised.

The Australian Automobile Association (AAA) tested the fuel efficiency of 21 cars. It compared its findings with advertised fuel consumption rates by car manufacturers.

More than half of the cars tested by the AAA were at least slightly less fuel efficient than advertised. Some cars were 20-30% less efficient than advertised.

The findings come ahead of new Vehicle Efficiency Standards which are expected to come into effect next year.

Fuel label

A fuel consumption label is advertised on the windscreen of every new car.

It shows how many litres of petrol a car uses, on average, per 100km.

These numbers are based on mandatory testing that takes place in a lab.


The AAA tested 21 different cars on a 90km route. The test drive included motorways, city and rural roads to reflect how the average Australian uses their car.

The ‘Real-World Testing Program’ found that 12 out of 21 cars consumed more fuel than their advertised fuel consumption rate.

Eight of those cars were between 6 and 31% less efficient than advertised.


The 2023 Suzuki Swift used 31% more fuel on the roads than advertised, according to the AAA findings.

The car recorded an average of 6.3L/100km in the real-world test. This is compared to the 4.8L/100km from the mandatory lab test, conducted by the manufacturer.

The 2021 BMW X3 recorded the second poorest result, using 20% more fuel during AAA testing than its lab result.

The car used 8.9L/100km in the real-world test compared to 7.4L/100km in the lab test.

Testing also recorded higher levels of pollutants than advertised in three car models.

AAA Managing Director Michael Bradley said consumers shouldn’t make efficiency or savings assumptions about cars based on manufacturer testing.

New standards

The AAA findings come after the Federal Government announced its new Vehicle Efficiency Standards.

The standards will come into effect from 1 January 2025, and will determine which new car models can be sold in Australia, based on how much petrol they use per kilometre.

The measure is designed to encourage companies to sell more low- and zero-emissions vehicles (e.g. hybrid or electric cars).


Energy Minister Chris Bowen said the new standards will give Australians “access to a bigger variety of more efficient vehicles.”

Transport Minister Catherine King said “advanced car, SUV and ute technology offered in other countries” will be “cheaper to run and better for the environment.”

Shadow Climate Minister Ted O’Brien has previously raised concerns that the standards could reduce choice for drivers.

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