McLaren's Juan Pablo Montoya was quickest at Jerez today, as the seven Michelin-shod teams that 'retired' from last weekend's United States Grand Prix, got back to work.

There was one MP4-20 present at the Spanish circuit and this was driven by Juan Pablo, while Alex Wurz drove an MP4-19B as the team awaits the return of the MP4-20 chassis used in the Canadian and US races.

Alex’s programme focused on Michelin tyre testing for the forthcoming French, British and German Grands Prix. While Juan Pablo concentrated on performance testing, including suspension development work.

Second quickest was Ricardo Zonta, who was scheduled to make his (race) return to F1 last weekend, following Ralf Schumacher's crash on Friday. The Brazilian was joined by French veteran, Olivier Panis, who will drive the Japanese team's third car at Magny-Cours next week.

BAR had three drivers on duty - though under the terms of the agreement with the 8 other 'rebel' teams, did not run them all at the same time.

Anthony Davidson had a successful day running through an aerodynamic evaluation. He completed a total of 114 laps, setting the fourth fastest time of the day.

Enrique Bernoldi was in action in the morning, working through a suspension and brake evaluation programme. In the afternoon he handed over to Adam Carroll, who was having his first run in the 007.

The Ulsterman was the cause of one of the day's few red-flags, when he span off and (lightly) hit the barriers.

On the day that BMW announced that it had bought into Sauber and would be entering F1 in its own right, Jacques Villeneuve served notice that he would like to be considered for any future job vacancy. The Canadian finished fourth quickest, just 0.459s off Montoya's pace.

"Today we focused on assessing several cooling options in preparation for forthcoming hot weather races," said Paul Russell, the Swiss team's test engineer, "and today's high ambient and track temperatures helped us to get clear ideas. We also worked on the set-up of the car and evaluated together with Michelin the tyre compound for the French Grand Prix next week. Overall, it was a good and productive test day for us.

"For the rest of the week we have planned to do long-runs for further Michelin tyre tests and to check new aerodynamic parts."

World Championship leaders Renault had Fernando Alonso and Franck Montagny on duty, the Frenchman guilty of two red flags, one following an off, and the other due to a technical fault which caused him to stop on track.

With the persistent breeze disrupting meaningful performance evaluation, both drivers concentrated on long distance running in the context of chassis set-up programmes.

Chief Test Engineer Christian Silk commented: "It was a difficult day owing to the windy conditions which made any truly representative work difficult. We nevertheless completed a good number of laps, in spite of several stoppages, and will try and build on this tomorrow as we prepare for the race in Magny-Cours."

Heikki Kovalainen will replace Fernando Alonso at the wheel of the R25 tomorrow. The Spaniard will resume testing on Friday after the completion of promotional duties.

Red Bull had Christian Klien and David Coulthard on duty, the Austrian losing out on much of the day's track-time as a result of a technical problem.