The Mercedes team unveiled on Monday morning the car with which it will compete in during the 2013 season Formula 1 season.
The W04 took to the Jerez circuit for the first time for a few early laps ahead of its official launch in the afternoon.
The team said the aerodynamic design has been optimised around a new five-element front wing and a second-generation Coanda exhaust. The car retains pushrod front suspension and a pullrod rear suspension.
Mercedes had a disappointing 2012 season despite scoring its first win since its return to F1, with Nico Rosberg winning the Chinese Grand Prix.
From then on its season went downhill and it endured a five-race point-less streak near the end of the year.
"2013 marks the start of a second era for our Silver Arrows works team," said team boss Ross Brawn.
"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.
"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."
Rosberg will be partnered by Lewis Hamilton this season, the Briton joining the Brackley-based squad after spending all his F1 career so far at McLaren.
Hamilton replaces seven-time world champion Michael Schumacher, who retired from the sport at the end of 2012.
After Monday's maiden run, the W04 will begin proper testing from Tuesday at Jerez.
Mercedes F1 W04 - full coverage:
2013 pre-season dates
Car launches Team Date
Lotus January 28
McLaren January 31
Ferrari February 1
Force India February 1
Sauber February 2
Red Bull February 3
Mercedes February 4
Toro Rosso February 4
Caterham February 5
Marussia February 5
Williams February 19 Testing
Jerez 5-8 February
Barcelona 19-22 February
Barcelona 28 February-3 March
Keep checking AUTOSPORT for the latest news from our reporters at every 2013 Formula 1 car launch, plus comprehensive galleries and in-depth technical analysis of the new cars