Mercedes ended the two-day in-season test in Bahrain on Wednesday leading the charts in both times and mileage while Ferrari suffered a setback in its bid to catch up to its rivals.
Lewis Hamilton's top time on new experimental tyres was 1.4 seconds quicker than the rest of the field and was the only driver to comfortably rack up more than 100 laps. Mercedes' programme focused on tyres, with the team conducting a range of evaluation tests on behalf of Pirelli in line with the regulations.
"It's been a long day… but driving a Formula One car is never boring," Hamilton said. "Of course, the nature of a tyre test means we haven't learnt anything in particular in terms of improving the car... They just gave me different sets and I told them how each felt."
In contrast, Fernando Alonso could do no more than 12 laps, ending up eighth in the charts, after Ferrari found the chassis damaged, halting its session prematurely as a precautionary measure.
Kevin Magnussen's day ended early as well after "a car problem" pitched his McLaren into the gravel just before lunchtime. The team then spent much of the remainder of the day in repairing the subsequent damage to the chassis and was only able to return to the track for the final half-hour of running, recording the third quickest time.
|© AP Photo/Hasan Jamali
Lotus concluded another miserable day at the bottom of the time sheets, completing only 16 laps in the hands of Romain Grosjean after yet another power unit failure.
"We did manage some aero work so we did collect some useful data, however we fell far short of what we wanted to achieve," admitted Grosjean.
Red Bull had yet another delayed start, this time because of an electrical issue, but recovered to gather plenty of aero data along with a few medium-length runs.
"There were no real performance runs, just pure testing," reported Daniel Ricciardo. "So, not really a day for the timesheets, but one for the people at the factory and the guys behind the laptops."
Jean-Eric Vergne was second in the Toro Rosso while the Force India of Sergio Perez was fourth. Jules Bianchi was sixth in the Marussia ahead of Giedo van der Garde, who lost about two hours due to issues with the power unit in his Sauber.
Caterham driver Marcus Ericsson was ninth followed by Williams' Felipe Nasr, who also carried out Pirelli's tyre test.
With a ban on tyre blankets to be enforced next season, the Italian tyre supplier tested the performance of the rubber in accordance to the new regulations set for 2015.
"Running a Formula One tyre when it hasn't been in a blanket was one of the most interesting things as it's very difficult to get them up to temperature, even in the Bahrain heat, it will be even more of a challenge at tracks such as Silverstone or Spa," Nasr explained.
The 250 experimental tyres brought to Bahrain, distinguished by being free from any colour stripes on the sidewall, were exclusively designed with 2015 in mind.
||Giedo van der Garde