An independent Newspoll for leading national tyre retailer Beaurepaires asked Queensland drivers about their knowledge of recommended tyre tread, inflation and safety inspection intervals, with the results suggesting drivers are apathetic about the condition of their tyres.

Among the research findings:

* Almost nine in 10 Queensland drivers (87 per cent) cannot say what a tyre's minimum roadworthiness tread depth is.

* Just over one in 10 Queensland drivers (13 per cent) know a tyre's minimum roadworthiness tread depth is 1.6mm.

* A third of Queensland drivers (34 per cent) check their tyre pressure, at best, once every two to three months.

* Four in 10 Queensland drivers (42 per cent) cannot say, or think the suggested interval for checking their tyre pressure is monthly or less often.

“Tyres are the only thing keeping a car safely on the road so it is somewhat concerning to learn most drivers don't know about the basic easy steps they can take to keep their tyres safe and roadworthy,” said Beaurepaires general manager Andrew Jose.

The total area of a tyre tread in contact with the road at speed is around 115cm, which is about the size of a CD case which underscores the importance of regular physical and visual inspection to ensure tyres are inflated correctly, and that they have uniform tread depth of at least 2mm and are wearing evenly.

Jose said the survey results were even more worrying when compared with the results of a random assessment of tyres on customers' cars at Mitre 10 stores.

Qualified Beaurepaires tyre fitters checked the tyres for inflation and tread depth.

An alarming number were unroadworthy and unsafe due to a combination of insufficient tread and incorrect inflation. The assessment found:

* 68 per cent of tyres were incorrectly inflated (over or under).

* 32 per cent of tyres did not have sufficient tread to be considered safe or roadworthy.

“A tyre is required by law to have at least 1.6mm of tread measured at varying points for it to be considered roadworthy, but we recommend if the tread is less than the 2mm mark then it's time to get new tyres,” Jose said.

Most tyres have tread depth indicators that appear when a tyre is wearing out.

Over and under inflation can cause a vehicle to over or under steer, and when a vehicle is travelling at speed this can have implications on a driver's ability to keep a vehicle safely on the road.

“Notwithstanding the safety benefits of correctly inflated tyres, drivers can also save money as fuel economy can be better for cars fitted with correctly inflated tyres,” Jose said.

Jose said if drivers had any concerns about the condition of the tyres they should consult a qualified expert.