BAR-Honda's Jenson Button set the pace on the third day of testing at Barcelona.

It was an incident filled day, with various drivers, including both WilliamsF1 and Renault drivers causing red flag periods, along with David Coulthard, Nick Heidfeld and Anthony Davidson.

Although the times show that Button was 1.7s ahead of his closest rival (Montagny). it should be noted that the Englishman was using a (restricted) V10 power-plant, as was the Renault tester. Fastest driver using a V8 was Jarno Trulli, who finished 0.4s quicker than teammate Ricardo Zonta.

Button spent the day switching between two 2004 cars, both using the V10, but both featuring a different aerodynamic package.

Anthony Davidson was also on duty for the Brackley team, the Englishman driving a 2006 'concept car fitted with the Honda V8. The car also featured a new gearbox and rear suspension.

Trulli had a good day, and is understood to be a little more comfortable with the TF106's handling now. Teammate Zonta however, lost valuable track-time as a result of a persistent fuel pump problem.

BMW wrapped up what it described as a "very productive" final day of testing, the German team not due back on track until next week at Jerez.

The Sauber C24B, fitted with the BMW V8 engine, ran flawlessly all day long. The engineers first concentrated on gathering more data on the engine and then conducted a tyre test programme for Michelin. The set-up changes that were made overnight proved to be a positive step.

"This was a successful first joint test," said Mario Theissen. "It was important that we could run the BMW P86 engine in the Sauber chassis at this early stage, in order to integrate all technical systems.

"This is the beginning of the testing season, and there is naturally a lot of work to be done," he admitted. "The co-operation at the track as well as the preparation of the interim chassis went very well - it was the first joint task of the new team.

"This test was the first of four that we will be conducting with the interim car before launching the 2006 contender on January 16 and 17."

It was back to work for David Coulthard, who joined yesterday's pace-setter, teammate, Christian Klien. Both drivers were running RBR1s equipped with (restricted) V10s, as they await the RB2 - due to make its track debut at Silverstone on December 16 - and the new powerplants from Ferrari, which are due in January.

Red Bull's other team, Scuderia Toro Rosso, was represented by Tonio Liuzzi, who once again ran an RBR1 equipped with the Cosworth V10.

Propping up the timesheets were the two WilliamsF1 cars, driven by Mark Webber and Nico Rosberg. The Australian completed a race distance mileage on the team's first day with the V8, he also carried out some set-up work.

His German teammate spent the day working through system checks and mapping. However, his track time was badly compromised as a result of faults on the hydraulic and pneumatic systems.

To check out our Barcelona test picture gallery, click here