Three of the vehicles tested released levels of pollutants that exceed relevant Australian regulatory laboratory limits.

The latest result arrive as the federal government pledged 75 per cent of new passenger vehicle purchases and leases across the public service must be low-emissions vehicles by 2025. Defence vehicles are deemed as operational and would be excluded from the edict.

New fuel efficiency standards are also due to be announced soon which will also step up pressure on car companies to offer consumers a wider choice of more efficient and less polluting vehicles.

The ability of car companies to manipulate static laboratory emissions tests was highlighted by the appalling Volkswagen "dieselgate" controversy of 2015, where one of the world's largest car makers used a clever software program to unscrupulously cheat and mask the excessive emissions of its diesel-powered cars.

The $14 million real world testing program, conducted in Victoria under the auspices of the Australian Automobile Association, was funded by the federal government to "empower motorists and fleet buyers to make purchasing decisions based upon real-world running costs, rather than figures obtained in laboratory testing".

The first round of real-world tests concentrated on small and medium SUVs. Among the nine vehicles tested, four delivered fuel consumption within 2.5 per cent of lab test results.

Fuel consumption among the remaining five vehicles ranged from 8 per cent to 13 per cent more than had been recorded in laboratory tests.

One of the big shocks from this first tranche of testing was that two big-selling models from Toyota, one of Australia's most trusted brands, both used more fuel than the company claimed.

The Toyota RAV4 Hybrid used 2 per cent more and the conventional petrol model 13 per cent more.

Both were also higher emitters out in the real world than in the laboratory.

AAA chief executive Michael Bradley said there had been 23 baseline tests to ensure the veracity of the testing regime and "Australian families and fleet buyers can place their faith in the reliability of these results".

International studies have highlighted large gaps between laboratory and real-world performance of new vehicles.

A 2017 study of 30 popular light vehicles found on average they consumed 23 per cent more fuel in real-world conditions. In addition, the real-world results by 11 of the 12 diesel vehicles tested exceeded regulatory laboratory noxious emissions limits.

The program will test 200 cars, SUVs, utes and electric vehicles over the next four years.