Rosberg and Mercedes fire ominous warning on day two

Mercedes finally hit the front in 2015 pre-season testing on Friday, as Nico Rosberg set an imperious new benchmark on day two in Barcelona. Elsewhere there was encouragement for McLaren, as Jenson Button completed more than 100 laps on the team's most successful day to date, and Force India, who rolled out their new car for the first time

via Formula1.com - Latest Headlines http://ift.tt/1860HzD