Teams and tyres gear up for heat and rain

But with the race swapping from its usual late-season date to an early slot on the calendar, it may also see the first real head-to-head between Bridgestone and newcomer Michelin's rain rubber.

Although they should know what's in store by now - Kuala Lumpur is just north of the equator and is therefore subjected to fairly constant hot conditions all year round - the high humidity could have an adverse affect on drivers and cars alike.

The temperature for Friday, Saturday and Sunday is a sweltering 33 deg C. But with humidity levels topping 91 per cent it will feel much warmer. Drivers' fitness levels will be tested in this muggy atmosphere and engine cooling and tyres could well suffer.

"The challenge at Sepang is to have tyres that grip well but also perform consistently in the hot weather," said Bridgestone's Technical Manager Hisao Suganuma. "I believe our tyres will perform well both during qualifying and the race, because they have good initial grip and behave consistently."

The thunderstorms predicted on Thursday, Friday and Saturday night could lead to the early morning practice and warm-up sessions being run on a wet but-drying track. However, sunshine is forecast for qualifying and race days so the circuit should be fine for the key action of the weekend.

Suganuma says his company is ready for wet conditions after its teams, which include Ferrari, McLaren and BAR, tested at Silverstone, Magny-Cours and Fiorano last week.

"All three tracks had rain at some point in testing," he said. "It gave us plenty of opportunity to gather some useful data regarding the wet-weather compounds we will have in Malaysia."

Partly cloudy; high 33 deg C; low 25 deg C
Sunny; high 33 deg C; low 25 deg C
Sunny; high 33 deg C; low 25 deg C