Felipe Massa set the fastest time of a damp final day of testing at Jerez as Red Bull left early and Mercedes completed more impressive mileage.
Early rain left the track wet for the morning session and although it dried throughout the day lap times were still some five seconds off Thursday's pace. Massa completed 86 laps with a best time of 1:28.229 to leave him almost a second clear of his former team-mate Fernando Alonso in the Ferrari.
Alonso enjoyed a productive day as he completed 115 laps – the most by any one driver – but it was Mercedes which can boast the highest total after Nico Rosberg managed 91 laps in the morning alone – including a race simulation – before handing over to Lewis Hamilton to add another 41 laps in the afternoon.
That running was in stark contrast to Red Bull, with Daniel Ricciardo only completed seven laps before the team called an early end to its test with just 21 laps to its name. A fresh mechanical problem was to blame for the latest stoppage, but the team will return to Milton Keynes looking to rectify cooling issues.
Kevin Magnussen covered a lot of mileage – completing 110 laps – but ended the day on a negative note with a spin in the final hour before crashing his McLaren with ten minutes remaining. Magnussen hit the tyre barrier and damaged the front of the MP4-29, and with Daniil Kvyat's Toro Rosso also stopping on track it brought proceedings to a slightly premature end.
Kvyat managed just nine laps on Friday – which was also his total for the week – as Toro Rosso's problems continued, but Caterham enjoyed a more successful day for a Renault-engined car as Kamui Kobayashi racked up 54 laps.
It was an impressive debut in the Force India for reserve driver Dani Juncadella as he set the third fastest time – 1.2s off Massa's best – and completed 81 laps across the day.
There was another spin for Adrian Sutil in the Sauber following his crash on Thursday, while Jules Bianchi also gave Marussia a bit more track time with 25 laps, leaving Red Bull with the lowest total of all the teams four days of testing.
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