For the second successive day, McLaren's Juan Pablo Montoya dominated the timesheets at Jerez.

In temperatures reaching 29 degrees C (air) and 41 degrees C (track), the Colombian posted a best time of 1:17.405.

Alex Wurz had been due to continue with Michelin tyre development work for the forthcoming French, British and Mobil 1 German Grands Prix today, however after eight laps he returned to the pits and reported a twinge in his shoulder blades.

He then visited the medical centre where he was treated for a trapped nerve and advised to sit out the remainder of the test. Consequently Alex did not get back in the car today and will be replaced for the final day of testing on Friday by Pedro de la Rosa.

With the team down to one driver, Montoya in an MP4-20 completed some of the Michelin tyre testing programme which had been scheduled for Wurz, alongside his planned performance testing programme, focusing on suspension and gearbox development work.

However, Juan's Pablo's test ended at 15:45 when he stopped on the circuit. The team diagnosed an engine problem and as a precautionary measure decided to end his test prematurely. The engine will be sent back to Mercedes-Ilmor in Brixworth this evening and the test team will complete an engine change tonight so that Kimi Raikkonen can take over testing duties on the final day.

Hot on the heels of the Colombian was the BAR duo of Jenson Button and Takuma Sato.

Button spent the morning running through an aerodynamic evaluation. He had a productive morning and completed his full programme, although his last run was aborted due to Heikki Kovaleinan's engine failure which covered a large section of the track with oil.

Takuma ran through a series of suspension evaluations, alongside a brake test. He completed 50 laps during the morning.

Both drivers spent the afternoon session running through a Michelin tyre evaluation in preparation for the French Grand Prix next weekend.

Renault experienced a frustrating day's testing in Jerez. In high temperatures, the team's programme was disrupted by a number of stoppages which cost both drivers valuable track time. However, progress was made with the tyre programmes.

"We had another difficult day," admitted Christian Silk, "but nevertheless completed some useful running – particularly with Franck's car towards the end of the day. We are hoping for a trouble-free day tomorrow, when Fernando will once again be back in action, in order to complete the essential items of our preparation for the next two races."

Toyota had Zonta and Panis on duty, though the French man only drove in the morning.

As Williams began its preparations for the forthcoming races in Hungary and Turkey, Nick Heidfeld and Antonio Pizzonia were present. Antonio focussed on tyre testing while Nick Heidfeld tested new bodywork. Unfortunately, an overheating problem on the German's car meant he only covered 28 laps, while the Brazilian's day came to an unscheduled end when he crashed, causing yet another red flag.

"Nick completed some exploratory running of the new MK2 bodywork," said test team manager, Tim Newton "Over the course of the day, we identified some expected teething problems which we will be working on this evening before re-evaluating tomorrow. At present, it looks promising but we have some homework to do."

David Coulthard and Christian Klien were present fro Red Bull, the Austrian having to 'abandon ship' when his car caught fire out on track.

Sauber continued its three-day test with Jacques Villeneuve covering 108 laps

"In the morning we evaluated new aerodynamic configurations and packages, and then continued with some set-up work," said Paul Russell, the team's test engineer. "Later we did long-runs to further assess Michelin tyres for the race in Magny-Cours. We achieved what we planned for today and seem to have good results.
"Tomorrow Felipe will carry on with the Michelin tyre programme and will also run aerodynamic tests."