BMW set the pace in practice 3 - Australia

Heidfeld recorded a fastest lap of 1:35.335 in the final stages of a wet-and-dry session run in changing, windy and unpredictable conditions at Albert Park.

His teammate Villeneuve was second fastest, with a time of 1:36.281.

This left the two BMW drivers ahead of Tonio Liuzzi, who was third fastest for the Toro Rosso Cosworth team, ahead of Italian compatriot Giancarlo Fisichella in the leading Renault.

Ralf Schumacher, in a Toyota, was fifth ahead of the two Ferraris - Felipe Massa taking sixth place ahead of teammate Michael Schumacher.

Defending champion Fernando Alonso was 17th, a full four seconds slower than the two BMWs who made the best of a drying circuit in the final minutes.

The hour-long session was run on a wet circuit, and oil was cleared from four of the opening corners as the cars began lapping.

It was little wonder that there was a long sequence of incidents with virtually everyone spinning off and regaining control all over the track.

In the opening 20 minutes, the off-track drivers included Massa, Yuji Ide in his Super Aguri Honda, Jarno Trulli in his Toyota, Juan Pablo Montoya in a McLaren, and Nico Rosberg in a Williams Cosworth.

Alonso, testing tyres and the circuit's conditions, went off twice at the opening turn in the first half hour as well, before the track began to dry, but even then as conditions improved, there were plenty more drivers taking a route across the grass.

Remarkably, the only driver to lose his car in the gravel trap and abandon it was Christijan Albers in his Midland Toyota, soon after the halfway mark in the session.

In all of this chaos, which included an off-track excursion for local hero Mark Webber in his Williams, the Renaults were the fastest cars in the early stages, with Fisichella and Alonso trading times.

On the half hour mark, Jenson Button took over at the top in his Honda before Villeneuve, then Fisichella and Villeneuve again clocked quickest laps.

As the sun flickered through, and a drying wind took grip, the track began to dry, but there were still wet areas under the trees, the leading men began to try running on dry-weather tyres.

The Renaults led the way, but both found life difficult and Fisichella ran off and on at turn 15 before the BMWs delivered the fastest laps of the day.

Notably, McLaren chose to run very lightly, conserving their cars for qualifying.

Pos  Driver        Team                     Time              Laps
 1.  Heidfeld      BMW-Sauber          (M)  1:35.335           10
 2.  Villeneuve    BMW-Sauber          (M)  1:36.281 + 0.946   16
 3.  Liuzzi        Toro Rosso-Cosworth (M)  1:36.373 + 1.038   10
 4.  Fisichella    Renault             (M)  1:36.414 + 1.079   13
 5.  R.Schumacher  Toyota              (B)  1:36.445 + 1.110   10
 6.  Massa         Ferrari             (B)  1:36.506 + 1.171   11
 7.  M.Schumacher  Ferrari             (B)  1:37.332 + 1.997   10
 8.  Barrichello   Honda               (M)  1:37.481 + 2.146   15
 9.  Trulli        Toyota              (B)  1:37.492 + 2.157   10
10.  Speed         Toro Rosso-Cosworth (M)  1:37.852 + 2.517   11
11.  Klien         Red Bull-Ferrari    (M)  1:37.947 + 2.612   12
12.  Webber        Williams-Cosworth   (B)  1:38.036 + 2.701    7
13.  Button        Honda               (M)  1:38.505 + 3.170   11
14.  Coulthard     Red Bull-Ferrari    (M)  1:38.683 + 3.348   15
15.  Rosberg       Williams-Cosworth   (B)  1:39.401 + 4.066   11
16.  Monteiro      MF1-Toyota          (B)  1:39.515 + 4.180    7
17.  Alonso        Renault             (M)  1:39.654 + 4.319   11
18.  Ide           Super Aguri-Honda   (B)  1:40.261 + 4.926   18
19.  Sato          Super Aguri-Honda   (B)  1:41.448 + 6.113    5
20.  Montoya       McLaren-Mercedes    (M)  1:44.350 + 9.015    3
21.  Raikkonen     McLaren-Mercedes    (M)  1:48.284 +12.949    3
22.  Albers        MF1-Toyota          (B)  No time             3

All timing unofficial