Australia Weather News

As temperatures push above 35 degrees along the east coast, what does the extreme heat do to tyres driving on hot, often bubbling roads?

Bitumen absorbs the summer heat, often making road surfaces more than 20 degrees hotter than air temperatures.

McElrea Racing, a motor racing team based in Yatala south of Brisbane, said the hot weather had them paying close attention to their tyres.

"We tested the Queensland Raceway at Willowbank on Tuesday and the actual road temperature was 60 degrees," workshop manager Michael Flanders said.

"The outside air temperature was over 36 degrees."

The team has been practising at the raceway this week ahead of the Bathurst 12-Hour endurance race on February 5.

Although the race cars are water-cooled and cope with the heat, the track temperature was calculated before each session to keep the tyres in check.

"If the temperature of the track is too high and we don't set the pressure right, then the car won't handle as we want it too," Mr Flanders told ABC Radio Brisbane's Steve Austin.

"The hot air causes the tyre to expand which then gets to an upper limit of the pressure we want the tyre to sit at.

"If it gets higher than that it won't perform at it's optimum."

Nitrogen more stable than air

The Queensland race team runs multiple cars in numerous championships around the country including Australia GT and Carrera Cup racing.

The team uses nitrogen in its tyres, not air.

"Nitrogen reacts better with temperature and pressure as it's more stable," Mr Flanders said.

"Temperature and pressure work side by side and if it gets too high, it makes the tyre unstable.

"It also allows us to know how long the tyre will last for.

"If a tyre is cold it does not grip well, but when a tyre is too hot it gets out of shape and does not get good grip."

ABC