SILVERSTONE -- Lewis Hamilton topped final practice for the British Grand Prix before drizzle in the final 20 minutes of the session made conditions too treacherous for slick tyres.
The top three drivers were split by 0.074s, with Sebastian Vettel just 0.032s off his title rival Hamilton and 0.042s ahead of the second Mercedes of Valtteri Bottas. The quick times were all set on super-soft tyres before a band of light rain swept across the circuit and put an end to meaningful qualifying simulation runs.
All drivers returned to the track on intermediate tyres in the final five minutes, but only managed a handful of laps to gauge grip levels before completing a practice start at the end of the session. Daniel Ricciardo and Marcus Ericsson both spun in the tricky conditions, with the majority of the field setting lap times 15 seconds off the times they set in the dry.
The battle at the front looks set to be tight in qualifying, although Bottas will drop five places from wherever he qualifies due to an unscheduled gearbox change overnight. That is likely to leave a straight battle between championship leaders Vettel and Hamilton, although in recent races Mercedes has been able to find more additional performance from its most powerful engine mode in qualifying.
Kimi Raikkonen finished the session 0.669s off Hamilton's pace in a no-man's land on the timing screens between Bottas' Mercedes and Nico Hulkenberg's Renault, which was fifth fastest and 1.417s off the ultimate pace. Daniel Ricciardo was seventh fastest for Red Bull but also has a five-place grid penalty hanging over him for an unscheduled gearbox change.
Fernando Alonso has the largest grid penalty of all after a new power unit was fitted to his car this morning adding an extra 25-place grid penalty on top of the five-place penalty he had following a battery change on Friday. He finished the session 11th fastest behind teammate Stoffel Vandoorne in 10th, Felipe Massa's Williams in ninth, the Red Bull of Max Verstappen in eighth and Romain Grosjean's Haas in seventh.
Force India's Esteban Ocon was 12th fastest ahead of Kevin Magnussen's Haas and Jolyon Palmer in the Renault. Sergio Perez was 15th ahead of the two Toro Rossos of Daniil Kvyat and Carlos Sainz with the Saubers next in line, a tenth off the Toro Rossos and ahead of Lance Stroll, who was focusing on longer runs before the rain hit.