Red Bull "on the back foot" at start of Formula 1 season

Red Bull have run "a third of the mileage of other teams" ahead of the 2014 Formula 1 season, team principal Christian Horner has said.

A problem with the team's new engines has seen World Champion Sebastian Vettel complete just 77 laps in pre-season testing, less than half the amount of his rivals like Mercedes driver Lewis Hamilton.