Barcelona: The build-up to the 2015 Formula One season steps up a gear when the second of three four-day pre-season tests gets started in Barcelona on Thursday.

There was a familiar sight when testing began in Jerez earlier this month as the Mercedes of world champion Lewis Hamilton and Nico Rosberg was literally miles ahead of the competition, completing 516 laps over the four days. Mercedes won 16 of 19 Grand Prix last season and seemed intent on ironing out a few reliability problems that prevented even greater dominance in 2014.