It's been a long time since Williams stood atop the Formula 1 world, but back when they were, nobody could take them down. They've won seven drivers' championships, with such pilots as Nigel Mansell, Alain Prost, Jacques Villeneuve and Ayrton Senna – and taken nine constructors' championships just to wash 'em down. But that was a long time ago, and since then the team has fallen far from the top. Could this be the year they come back?
With F1's technical regulations turned all topsy-turvy for 2009, Williams was the first to start preparing. They're also the only team to go with a mechanical Kinetic Energy Recovery System, opting for a flywheel to store recovered braking energy instead of the battery-based systems developed by the other teams. The flywheel is installed in the new FW31, powered by a Toyota engine and unveiled at the new Algarve circuit in Portugal, where several other teams – including Renault – came to test out their new gear. Test driver Nico Hulkenberg was behind the wheel, soon to be joined by lead drivers Nico Rosberg and Kazuki Nakajima, who remain with the team for 2009. Check out the new Williams FW31 – wearing interim dark blue livery for the off-season – in the gallery below.