Ahead of this morning's free practice session, the air temperature is 19 degrees C, while the track temperature is 21 degrees. It's dry and fairly sunny.

After yesterday's sessions, when the third drivers swelled the number of drivers on track to 28, today we revert to the 22 drivers who will contest tomorrow's Spanish Grand Prix.

The lights go green, and after a few moments hesitation Takuma Sato gets the session underway, heading out on to the Barcelona track, followed by Monteiro, Montagny and Albers.

While the others return to the pits, Montagny continue round, posting the first time of the day, a 1:22.594. Next time around the Frenchman whittles it down to 1:22.046.

The former Renault tester continues lapping the Spanish track, locking up here and there, but is unable to lower his time any further.

Nine minutes into the session, Jacques Villeneuve heads down the pitlane, the Canadian already hampered by the fact that he will forfeit ten grid spots following the mysterious accident that befell his BMW powerplant en-route to Spain from the Nurburgring. The Canadian's good friend, David Coulthard, about to take part in his two-hundredth Grand Prix, opts to join him on track, as do Albers and Monteiro.

Unsurprisingly, Villeneuve goes quickest, crossing the line at 1:20.948. Next time around he gets down to 1:19.350, but this is soon beaten by Coulthard, who crosses the line at 1:19.275.

As Jarno Trulli heads down the pitlane, Villeneuve improves to 1:19.148. Monteiro is third (20.348), ahead of Albers and Montagny.

Villeneuve lowers the benchmark even further, the Canadian clocking 1:19.001, as Liuzzi leaves the Red Bull garage. Elsewhere, Jarno Trulli can only manage 1:21.431.

Seventeen minutes into the session, and Felipe Massa heads down the pitlane, followed by Ralf Schumacher and Raikkonen.

Trulli improves to third quickest (19.991), but is soon demotes by Massa, who posts 1:18.704 on his first lap. This is the cue for Michael Schumacher to get to work, the German heads down the pitlane, pursued by Klien, Webber and Barrichello.

Ralf goes fifth, but is quickly leapfrogged by Raikkonen, who posts a 1:18.877 to go second. Massa raises the benchmark with a 1:18.178. Fisichella, Speed, Rosberg and Button are all on track.

Michael goes third (18.943), on his first lap, but immediately goes quickest in the first sector on his next lap. By the second split he is almost half-a-second up on his teammate. Sure enough, at the line it's 1:17.229. Elsewhere, Fisichella goes third, ahead of Klien, Raikkonen, Ralf, Barrichello and Trulli.

As Michael continues on another very hot lap, Mark Webber goes fifth, only to be demoted, almost instantly, by Button, who posts 1:18.463, to go fourth.

Juan Pablo Montoya leaves the McLaren garage, along with Heidfeld and Alonso, the Colombian is the only driver who hasn't yet posted a time.

Button improves to second with a 1:17.215), as Fisichella goes second and Montoya third, meanwhile, Michael has raised the benchmark with a 1:17.072.

A 1:16.999 sees Button go quickest, as Rosberg goes sixth (18.604), ahead of Klien, Villeneuve, Trulli, Webber, Raikkonen and Ralf. Alonso, who has yet to post a time, waits resolutely in his car.

Nick Heidfeld takes fifth spot with a 1:18.084, as Alonso heads off down the pitlane. Meanwhile, the BMW crew is working on a problem which has seen Villeneuve continually locking up.

Felipe Massa takes over half-a-second out of Button's best, posting a 1:16.410, to re-take the top spot. However, teammate Michael Schumacher is already back on track.

Fernando Alonso goes fourth (17.434), as Massa goes very wide at the final turn, kicking up a whole pile of dirt. Elsewhere, Kimi gives his Woking team a much-needed boost, taking second with a 1:16.756.

Michael is pushing hard, moving up to second spot with a 1:16.575, despite not being quickest in any of the sectors.

Interestingly, quickest through the speed-trap at this time is Villeneuve, at 193.86 mph.

Tonio Liuzzi goes quickest in the second sector, finally crossing the line at 1:17.240 to go fifth.

With fourteen minutes remaining, it's Massa, Michael, Raikkonen, Button, Liuzzi, Fisichella, Alonso, Montoya, Klien and Villeneuve.

The Toyotas and WilliamsF1s are well down the timesheets, with Webber (fourteenth) and Trulli (sixteenth) being the best placed drivers for their teams at this time.