BMW's Jacques Villeneuve topped the timesheets on the forth day of testing at Jerez.

With just five teams on duty, the Canadian, driving the V8 powered Sauber C24B, completed 101 laps, posting a best time of 1:18.752, the best time posted by a V8 this week.

Team engineers concentrated on a tyre test programme for Michelin and gathered more data on the BMW P86 V8. The engine ran flawlessly, and reached its mileage around noon and therefore needed to be changed. The crew continued testing later in the afternoon.

This was the final day of testing at Jerez this week for the German-Swiss team.

Second quickest was Friday's pace-setter, Pedro de la Rosa, in the V10 McLaren, as the Woking team concluded its programme for the week. The Spaniard was joined by Alexander Wurz, who drove the V8.

The team will remain at Jerez for the final test before the Christmas break next week, which begins on Tuesday 13th and lasts for three days. Pedro will be joined in Spain by Juan Pablo Montoya.

During the test sessions in Barcelona starting November 28, and the four days in Jerez, the team accumulated some 3,200kms on their new V8 engine.

Toyota, represented by Ricardo Zonta and Jarno Trulli, finished third and fourth quickest, as the team focussed on set-up and on the team's new Bridgestone tyres.

Both drivers had productive days, putting in a lot of laps and collecting useful data.

Zonta will return to action on Sunday to take part in a wet tyre test for Bridgestone.

Toyota is also scheduled to test here from Tuesday to Thursday next week (December 13-15) in its final outing of 2005.

"Overall, this has been a useful and constructive test, said test team manager, Gerd Pfeiffer. "We have had four days of running with four different drivers and it has given us a chance to put some mileage on the TF106 and to spend some time working on set-up with our new Bridgestone tyres.

"The cars have been reliable and we have collected a lot of useful data to help us learn what direction to take to get the best out of the rubber. We still have a lot of work to do over the winter but after Ricardo carries out tomorrow's wet tyre test we will have three more days of dry weather testing back here at Jerez next week."

Once again, Marc Gene was Ferrari's sole representative. The Spaniard, at the wheel of a V8 powered F2004 M, worked on development of the new engine in collaboration with Shell, while also looking at development of the Bridgestone tyres.

Gene and Wurz were the two busiest drivers, covering 111 laps each.

MF1 had four drivers on duty, with regular, Christijan Albers, joined by Markus Winkelhock, Roman Rusinov and Fabrizio del Monte.

Winkelhock, son of former ATS and RAM F1 driver Manfred, who was killed in a SportsCar event at Mosport Park (Canada) in 1985, was the quickest of the quartet.

While Albers' first task was to work on the set-up of the interim car chassis and getting more data on the new Toyota engine, Rusinov, del Monte and Winkelhock spent much of the allocated time acclimatising themselves to the levels of performance available from their EJ15B and then worked on a Bridgestone tyre programme. The test will come to an end for MF1 Racing on Sunday with a wet tyre test for all Bridgestone teams to help further develop wet weather tyres for next year.

"We have now gathered a considerable amount of data on the new engine formula for 2006 and will spend the coming days analysing this in preparation for a resumption of testing in the new year," said Dominic Harlow, MF1's chief race & test engineer. "We took the opportunity today to evaluate three new drivers in Markus Winkelhock, Fabrizio del Monte and Roman Rusinov. Each of them acquitted themselves very well and really did not put a foot wrong all day. Our final job here will be tomorrow when we are using one of our cars for an intensive wet tyre test for our tyre supplier Bridgestone."