Sebastien Buemi and Takuma Sato did their chances of securing a race seat with the Toro Rosso team for the 2009 Formula One season no harm by once again leading the way on the final day of testing at Jerez.

As was the case on the day two, Buemi led the way from Sato as Toro Rosso completed a clean-sweep of the times for the week - with Buemi having headed Sebastien Bourdais on the opening day on Tuesday.

Buemi's quickest time on Thursday of 1min 17.258secs was the quickest of the week and saw him end the day 0.262secs clear of Sato as the Japanese ace seeks to secure a return to the grid following the demise of Super Aguri.

After a day where both drivers completed well over 100 laps, the Toro Rosso pair were half a second clear of the third fastest man as Heikki Kovalainen completed a second day of running for McLaren. The Finn improving his time from Wednesday by over a second and half as he switched from the KERS car to the MP4-23A and spent a day running a tyre and aero programme.

Kimi Raikkonen was a further seven-tenths of a second back for Ferrari as the Scuderia continued development work ahead of 2009. Raikkonen also carried out an endurance test of the 056 engine and was followed on the times by team-mate Felipe Massa who took to the track for a full day of work after an afternoon behind the wheel on Wednesday.

The lone Renault of Fernando Alonso was sixth on the timesheets as the Spaniard completed the team's final day of testing for the year; Renault having elected not to take part in the test sessions taking place next week.

Working with the slick Bridgestone tyres and evaluating a number of new suspension set-up options, Alonso's focus will now turn to the new R29 which will make its first appearance in January.

"It was a good day as we continued to add miles to the car and to understand the tyres," he said. "We maximised the time on the track and managed to do a lot of laps as well as some basic-set-up work.

"I have already been doing a lot of physical work to get ready for next year and so spending a couple of days in the car this week was another important part of my preparation and has helped me get back up to speed. I'm now looking forward to testing the new car in January."

Alonso was less than a tenth of a second clear of Nico Rosberg, while McLaren test driver Pedro de la Rosa was eighth as he swapped cars with Kovalainen and put more miles on the MP4-23K KERS development car. However, a number of small issues meant he completed fewer laps than anyone else on track, managing less than 50 tours during the course of the day.

BMW pair Robert Kubica and Christian Klien completed the ten runners to take to the track, continuing work on both KERS and the 2009 aerodynamic package.

For testing times, CLICK HERE.