Team McLaren Mercedes test driver Alexander Wurz was fastest in both free practice sessions on the opening day of the Brazilian Grand Prix meeting at Interlagos. The Austrian's pace-setting lap in the opening session (1m 11.701s – 216.348kmh/134.514mph) was the best of the day and put him almost a second clear of team-mate Juan Pablo Montoya, who was quickest of the regular racers.

Michelin drivers took a clean sweep of the top 10 positions on aggregate. Ricardo Zonta was third ahead of Felipe Massa, Takuma Sato, Fernando Alonso, Jenson Button, Kimi Raikkonen, Giancarlo Fisichella) and Jacques Villeneuve.

Michelin partner BAR-Honda has confirmed that Jenson Button will stay with the team in 2006, to partner new signing Rubens Barrichello.

Williams-BMW reserve driver Antonio Pizzonia is standing in for Nick Heidfeld again this weekend. The German, who missed two races after concussing himself in a testing accident at Monza, is now recovering from a cycling injury.

Red Bull Racing driver Christian Klien escaped unhurt after crashing heavily at Turn Nine during today's second session.

Pierre Dupasquier, Michelin motorsport director: "There might not have been a great deal of difference between the lap times in today's two sessions, but the track conditions changed significantly during the day. They are likely to evolve again before the cars run tomorrow – but it is difficult to predict quite how. The weather forecast seems to change every couple of hours.

"We have brought three different types of tyre to this race– two primes and one option – and all were well suited to today's conditions. It is far too soon to know what our seven partners will choose for the race, but they have completed an enormous number of laps and we will have to pore over the data with great care. Our engineers have a great deal of thinking to do this evening."