Michelin drivers were fastest in the opening two free practice sessions of the Malaysian Grand Prix at Sepang.

Toyota reserve Ricardo Zonta posted fastest time of the day - a 1m 34.092s - during the morning; Felipe Massa (Sauber-Petronas) set the pace in the afternoon session, which was slower overall. On aggregate, Michelin filled nine of the top ten positions, with Zonta heading Pedro de la Rosa (Team McLaren Mercedes, second), Massa (third), Juan Pablo Montoya (Team McLaren Mercedes, fourth), Vitantonio Liuzzi (Red Bull Racing, fifth), Kimi Raikkonen (Team McLaren Mercedes, sixth), Ralf Schumacher (Toyota, seventh), points leader Giancarlo Fisichella (Renault), eighth) and Jenson Button (B7A7R-Honda, 10th).

Although drivers are obliged to use the same engine for two consecutive races this season, Nick Heidfeld (BMW WilliamsF1 Team/Michelin), Jenson Button (B7A7R-Honda/Michelin), Takuma Sato (B7A7R-Honda/Michelin) and Christijan Albers (Minardi-Cosworth) will not be penalised for using fresh V10s this weekend. They were allowed to make the switch after failing to finish the season-opening Australian GP a fortnight ago. Motor racing's governing body the FIA has clarified, however, that such changes will only be permissible in future if drivers fail to complete a race for reasons beyond their control. They will not be allowed "to choose not to finish".

After setting seventh fastest time in this morning's first free practice session, Kimi Raikkonen (Team McLaren-Mercedes/Michelin) sat out much of the second after spinning off at Turn Seven. Ferrari star Rubens Barrichello - 15th this morning - also failed to complete many laps in the afternoon. The Brazilian careered into the gravel at Turn 11, but like Raikkonen he returned to the track for the final few minutes.

Red Bull Racing's rookie test driver Vitantonio Liuzzi had a carbon copy of his opening day in Melbourne: the Italian was quick in the morning, when he set third fastest lap, but had to curtail his afternoon session early after a spin.

Williams-BMW driver Mark Webber spent most of the second session in the pits, because of a technical problem.

Pierre Dupasquier, Michelin Motorsport Director:

"Track temperatures have been every bit as hot as we anticipated, at about 50-55 degrees, but despite the conditions we have encountered no problems at all. The tyre compounds we are using this weekend are appreciably different from those we ran so successfully in Melbourne two weeks ago - it would have been a serious error of judgment to take any other approach, given the contrasting nature of this weekend's circumstances.

"We have managed to complete all our scheduled comparison tests and it is feasible that our 'prime' and 'option' tyres will both be used in Sunday's race. One is a little bit quicker than the other over a flying lap, but both are clearly capable of providing quick, consistent performance over a full grand prix distance."