SILVERSTONE, Great Britain -- Fernando Alonso finished the first day of this week's Silverstone test at the top of the timesheets after rain during lunch prevented lap time improvements in the afternoon.
Alonso set a time of 1:31.290 in the morning session using the super-soft tyres, beating his qualifying time at the weekend's British Grand Prix by nearly 0.5s. The McLaren driver was not put off by the rain in the afternoon, completing an additional 50 laps in the wet, including a long run in the worst of the conditions.
DTM driver Esteban Ocon completed the most mileage of any driver over the course of the day, with a total of 123 laps in both dry and wet conditions. His best time was 1.5s the top of the timesheets, but Mercedes stuck to a strict run plan of medium tyres when the track was dry in the morning, meaning Alonso's time was set on tyres two steps softer in Pirelli's range. Ocon will continue at the wheel of the 2016 Mercedes during the second day of the test on Wednesday in order to fulfil regulations that require young drivers -- a driver with less than three races experience -- to complete at least two of the four days of in-season testing available to teams.
Alex Lynn was third fastest in the Williams, 1.6s off Ocon as he worked through a test programme of 38 laps in the dry before completing a further 16 laps in the wet. He will hand over to race regular Valtteri Bottas on Wednesday.
Ferrari Academy driver Charles Leclerc was fourth fastest as he made his debut for the Italian team. After driving 25 laps in FP1 for Haas on Friday, Leclerc completed just 19 laps over the course of the day, with only two set in the wet conditions in the afternoon. Kimi Raikkonen returns to the track on Wednesday for a day behind the wheel of the SF16-H.
Nikita Mazepin was fifth fastest on his debut with Force India, racking up 35 laps in the morning and opting not to go out in the afternoon due to a lack of wet weather tyres. Carlos Sainz had no such concerns in the Toro Rosso, completing 91 laps as the team ran a new engine cover with two ducts either side of the airbox.
American Santino Ferrucci made his F1 debut for Haas, completing a total of 55 laps on the first of his two days in the car. The 18-year-old from Woodbury, Connecticut is a development driver for the American team and also races in the GP3 series that follows F1 to certain rounds on the calendar.
Pirelli completed 48 laps of testing with a 2014-spec Mercedes and Manor driver Pascal Wehrlein at the wheel. The objective was to kick off development work on its 2017 tyres, but with only slicks in the garage the test programme ended as soon as the rain began to fall. The tyres run were 2016 dimensions, but featured prototype construction materials and compounds that will be used in the wider tyres set to be introduced next year.
Rio Haryanto was ninth fastest in the Manor as the team continued to develop its latest parts, setting a time 0.944s faster than Sergey Sirotkin's best effort in the Renault. Pierre Gasly propped at the bottom of the timesheets after an electrical issue kept him in the garage for much of the morning when the track was dry at its quickest. He did, however, managed to complete the latest test of the Halo head protection device as Red Bull fitted a prototype to its car for the first time.