WilliamsF1 and McLaren shared an otherwise deserted Circuit Ricardo Tormo as the latest Formula One group test in Valencia drew to a close for the week.

As he had on day three, Kimi Raikkonen led the way for the Woking-based team, but he was pressed hard all the way by Juan Montoya, who was keen to regain the top spot he had held earlier in the week. While Raikkonen continued to work on the development of parts for the forthcoming MP4-18, the Colombian concentrated on furthering the progress of both Michelin's latest F1 tyres and the new BMW P83 engine.

Behind the 'big two', Marc Gene and Alex Wurz carried out their respective testing duties, along similar lines to their team-mates. Again, the battle between the pair was close, mirroring that between Raikkonen and Montoya, with Gene coming out on top by 0.09secs. There was no role on the final day for young Briton Gary Paffett, who had earlier found gainful employment by standing in for the unwell David Coulthard.

Both Montoya and Gene - and earlier in the week, Olivier Beretta - benefited from using a new fuel introduced by Petrobras that has been researched and developed at the Cenpes Research Centre in Brazil.

"As well as supporting the chassis and tyre development work on the car, we have also been able to complete an extensive engine development programme during
the Valencia test," commented BMW director Mario Theissen, "We had no unexpected incidents and we are pleased with the progress achieved. Our tasks were divided between testing new components for the P83 BMW engine as well as working on the engine's mapping. Step-by-step, we are finalising the engine's configuration for Melbourne."

Both teams will now return to base to examine the data provided by the test, with Williams not returning to action in Spain until after the launch of its new FW25 in Barcelona on 31 January.

Leading performances (24 January):

Kimi Raikkonen McLaren-Mercedes 1min 11.621secs 81 lapsJuan Montoya Williams-BMW 1min 11.634secs 70 lapsMarc Gene Williams-BMW 1min 11.901secs 85 lapsAlex Wurz McLaren-Mercedes 1min 11.910secs 88 laps

[all cars on Michelin tyres]