Pirelli has completed the first in-season test using the current 2014 cars: an innovation for this year designed to help the Italian tyre-maker develop suitable tyres for the latest-generation Formula One cars.

A total of eight new constructions and six new compounds were tested during the two days: split between Caterham on Tuesday then Mercedes and Williams on Wednesday. Only one variable was tested at a time, so if a new compound was being tested, then the construction would be the current one (and vice versa). The teams alternated prototype runs with baseline runs on the existing tyres, for comparison purposes.

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. Over the course of the two days, Pirelli completed a total of 110 laps and around 595 kilometres with experimental tyres, in ambient and track temperatures that were a lot hotter than those of the grand prix weekend.

The maximum temperature reached was 35 degrees ambient and 44 degrees on track at 2pm on Wednesday.

The fastest time set throughout the two days of the test was a 1:34.136s benchmark from Hamilton on Wednesday morning, on an experimental tyre.

As well as the running on experimental tyres, the teams that were not testing specifically for Pirelli ran with the current tyres. Teams are allowed an overall maximum total of 135 sets of tyres for testing this year, including the in-season tests.

Caterham ran a total of 64 laps with Robin Frijns on Tuesday before a hydraulic problem curtailed running in the afternoon. Frijns tested one new construction and two new compounds.

On Wednesday Mercedes ran a total of 120 laps with Lewis Hamilton, testing three new constructions and three new compounds. Williams ran a total of 64 laps with Felipe Nasr, testing two new constructions and one new compound. The team stopped in the afternoon with a technical issue.

Paul Hembery: "The opportunity to test with the current cars is something that we have always wished for and it was vital to have this written into the regulations this year. We made useful progress throughout both days of the prototype tyre test, trying out a number of solutions with 2015 in mind, in demanding conditions. Having accumulated this valuable data over two days, we will now analyse it carefully to assess the best development direction for the next in-season test in Barcelona, where we expect to see further evolutions in car performance."

The next in-season test will take place after the Spanish Grand Prix. Sauber and Toro Rosso will test for Pirelli on the opening day, followed by Force India and McLaren on day two. The final tyre test will be held at Silverstone, after the British Grand Prix. Ferrari and Lotus will drive on the opening day, followed by Red Bull and Marussia on day two.

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