The Williams car has attracted attention with the design of its rear
Williams said they would be competitive in 2011 as they unveiled their blue and white livery for the new season.
The British team finished sixth in 2010 but have come up with a unique rear design for the FW33 and appear to have taken a step forward in testing.
"All the testing has shown that we have a competitive car," said the team's technical director Sam Michael.
"As long as we develop the car quickly, we can have a good year. As a team, we are more ambitious than ever."
A new set of regulations for 2011 means the Formula 1 field has had to re-think their car design and many teams, including Williams, have caught the eye.
The rule changes include the return of the kinetic energy recovery device (Kers) and tyre supplier Pirelli, the introduction of a moveable rear wing and the removal of the double diffuser and F-duct - which has meant teams have had to come up with new ways to improve aerodynamic performance and gain downforce.
We know it's not easy but we hope that this car will take us a step closer to the leaders
Williams technical director Sam Michael
"Teams have had to take much bigger risks," Michael said.
"There's the Williams gearbox, the Red Bull exhaust system and the way it blows the diffuser, the Renault [forward-facing] exhaust system and the way it blows the front of the diffuser and the Toro Rosso double floor.
"Those four things are the ones that stand out."
Williams have focused on the rear design of their car, with a lower, tightly packaged gearbox and extreme-angled rear driveshafts.
In the first three pre-season tests, Williams have been slowed by problems with the rear wing and Kers but have otherwise been productive with Rubens Barrichello setting the
at the second test in Jerez.
The team believe they have taken a step forward in performance but whether they can move ahead of the midfield pack, which includes Mercedes, Renault, Force India, Sauber and Toro Rosso, and closer to front runners Red Bull, Ferrari and McLaren remains to be seen.
New racers put through paces at Valencia (UK only)
"We've had some annoying systems problems but we've done 3800 kilometres and testing has been very good," said Michael.
"There is a big group of teams in the middle where you can't predict where people are. We know it's not easy but we hope that this car will take us a step closer to the leaders."
Rubens Barrichello, 38, will spearhead Williams' campaign for the second season running alongside Venezuelan rookie
Maldonado secured his place in the Williams team with a hefty sponsorship package from state oil company PDVSA but Michael has been pleased with what he has seen so far from the 25-year-old.
"One of the things I liked is that Pastor is definitely naturally talented," Michael added. "He's a rookie, he'll make a few mistakes but I'm impressed.
"Rubens is the key driver for the direction of the car because someone with that experience can't be matched. He contributes the most."
The drivers will get back to work at the final test at Barcelona's Circuit de Catalunya between 8-11 March.
The season opens with the Australian Grand Prix on 27 March after the
Bahrain Grand Prix
was called off because of political unrest in the Gulf state.