Silverstone, England Lewis Hamilton and Kimi Raikkonen had the best times in Friday's practice session for the British Grand Prix.
Hamilton, who leads the standings over McLaren teammate Fernando Alonso, clocked 1 minute, 21.100 seconds in the morning session at the 3.2-mile Silverstone circuit. Hamilton will try to extend his 8-for-8 streak of top-three finishes in his rookie Formula One season.
Raikkonen, who won last week's French GP, was the fastest in the afternoon for Ferrari in 1:20.639. In the first session, he was second with 1:21.211, just ahead of teammate Felipe Massa in 1:21.2855.
Alonso, the two-time defending champion with Renault before moving to McLaren this season, had a mixed day. He was fourth in the morning in 1:21.675, and sixth later in 1:21.616. He won last year's race.
Those four have each won two of this year's eight races, as McLaren and Ferrari battle for supremacy.
Hamilton leads the driver standings with 64 points, 14 ahead of Alonso and 17 in front of Massa with nine races remaining.
"To win at this race would be immense, but we have to be realistic with our expectations," Hamilton said.