While Toro Rosso continues to top the timesheets at Jerez, Lewis Hamilton was the quickest of the 2009 runners at the Spanish circuit today, albeit using a 2008-spec rear wing, Sebastian Vettel, in the Red Bull, was just one-thousandth of a second slower.

For Toro Rosso, it was another high mileage day with Sebastien Bourdais back in the cockpit for the first time since re-signing for the Faenza team. The job sheet included a comparison test between the soft and medium compounds, as well as set-up work and evaluation of some front suspension options.

Also ongoing was a reliability validation of the Ferrari engine, which should complete its cycle tomorrow, when Bourdais will again get behind the wheel for the final day of this test.

Lewis Hamilton picked up where Heikki Kovalainen left off yesterday, spending the morning concentrating on aero mapping and finding a good balance ahead of the afternoon's long runs. According to the Woking outfit, the day was extremely productive and saw the team continue with its KERS programme.

"Today's test gave me the first opportunity to drive MP4-24 in warm, dry conditions," said Hamilton, "and I'm very encouraged by what I felt. The car feels strong, very similar to last year's car, in fact. It doesn't take long to get used to the new buttons in the cockpit (KERS & front-wing flaps) but the real test for everyone now is to understand the slick tyres ahead of the first race in Melbourne next month."

Sebastian Vettel was back in the cockpit for the penultimate day of this four day session. Following a long run in the morning, the car was sidelined with some bodywork damage that took a couple of hours to fix. After that, a very productive afternoon saw the Milton Keynes outfit make up for lost time to get through the day's to-do list, which included some aero testing and work on mechanical set-up. Tomorrow, Mark Webber gets his second day in the new car.

At Williams, Kazuki Nakajima continued to work on set-ups and completed some systems and cooling checks.

"We have some useful information which we will look into tonight in preparation for tomorrow's session," said Sam Michael. "Nico Rosberg joins the team for the last day and will share pitstop practice work with Kazuki in the morning before taking over the FW31 for the final half day of testing in the afternoon."

Fernando Alonso had a busy day in the cockpit clocking up 133 laps in the R29. The Spaniard's programme consisted of long runs and evaluating various development items. There was also continuation of work on the KERS system.

"Today was all about getting mileage on the car," said the two-time world Champion, "especially with the new KERS system. It was my first full dry day in the car and so I was able to learn a lot. We completed lots of laps, which is encouraging and now we will start working on the set-up of the car so that I can get more comfortable with it."

"As the car is so new, the main priority of this test is to add miles to the car to get data and ensure we have a reliable package," added Christian silk. "The first two days of the test were quite difficult for us, but today was better and the car ran well throughout the day. For tomorrow we will keep pushing on the mileage and learning all we can about the package."

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