Sauber's switch to Michelin rubber continues to pay off as Felipe Massa dominated proceedings at the Circuit de Catalunya today.

The Brazilian, who concentrated on aerodynamic evaluations and brake testing, posted a best time of 1:14.664, the fifth fastest time of the year at the Spanish track.

It wasn't a trouble-free day for the Brazilian however, in the afternoon he suffered a technical problem which saw him stranded out on track, causing the session to be red-flagged. Tomorrow (Friday), Jacques Villeneuve makes his debut with the Swiss team.

"I was surprised how quick we were able to adjust the car to the new tyres," said the Brazilian at the conclusion of the day's activities. "We only made rather small changes and the balance of the car as well as the performance were good straightaway. We now have a solid basis on which we can build."

Toyota is also showing a major step forward in terms of performance, drivers Jarno Trulli and Ralf Schumacher finishing second and third quickest.

Mark Webber and Antonio Pizzonia were on duty for WilliamsF1. The Australian continued to familiarise himself with the FW26, as he focussed on set-up work. In the afternoon, Webber, who suffered an engine problem in the morning, worked on tyre compound evaluations for the Michelin.

Following yesterday's technical problems, today was trouble-free for Pizzonia. The Brazilian worked on set-ups in addition to evaluating gearbox settings.

Vitantonio Liuzzi looked mighty impressive as he posted the fifth fastest time of the day, outpacing his Austrian teammate, Christian Klien, by almost a second.

Renault's Giancarlo Fisichella was sixth quickest, the Italian completing 89 laps. The French outfit's test driver, Franck Montagny, was over two seconds slower.

Having topped the timesheets yesterday, Juan Pablo Montoya could only manage eighth quickest today, only narrowly outpacing McLaren teammate, Alexander Wurz. The Colombian went off at the Banc de Sabadell but was able to continue, while Wurz worked on aerodynamic evaluations. Tomorrow, Pedro de la Rosa is on duty for the Woking team.

Ferrari had Luca Badoer and Marc Gene on duty. The two testers for the Maranello outfit worked on tyres, new components and electronics.

Once again, the BARs were well off the pace, with Enrique Bernoldi only marginally out-pacing Jenson Button, though both were over 2s off Massa's best time.

Times