Mercedes launch W04 at Jerez pre-season test

Mercedes debuted their 2013 car during a filming day at the Jerez circuit on Monday, a day before pre-season testing begins at the Spanish venue.

The W04 was uncovered by Nico Rosberg and new signing Lewis Hamilton, before the duo got behind the wheel for some shakedown laps.

Team principal Ross Brawn described the car as a "clear step" forward over the disappointing W03 which, although it won the Chinese GP, failed to challenge for much else.

"The restructuring we undertook at the team over the past 18 months are now growing in maturity and this is reflected in the F1 W04, which is a clear step forward in design and detail sophistication over its predecessor," said Brawn at the launch.

"Many thousands of hours of work have been invested by our technical teams in Brackley and Brixworth to ensure that the new car delivers a step change in performance compared to last season."