Pastor Maldonado has hailed Williams' first outing in the FW35 after a problem-free four days at Barcelona.
Williams was the only team not to run their 2013 car at the opening test in Jerez, a move that surprised those who like to bet on F1, instead opting to launch the FW35 at the start of the second outing.
Maldonado and his new team-mate Valtteri Bottas shared the driving duties over the four days at the Circuit de Catalunya.
Maldonado completed 178 laps with a best time of 1:22.675 to add to the 189 laps his team-mate covered, a performance that has seen them installed as outside title favourites with bookmakers like Paddy Power and others.
"We had a wonderful four days. No problems in the car," said the Venezuelan driver.
"The car is looking quite good in terms of reliability, even in terms of performance, but it's still quite early to see where we are but we are doing our best to be there in the first race.
"This is early days for the car, only four days, but I think the next test next week we will have more clear ideas. We got good data from here, we have a lot of data to compare and a victory from last year, so we have a lot to compare.
"It's looking quite good and the car feels really good as well. Actually, there is a step forward in terms of feeling with the car but we don't know what the other teams have prepared for this season.
"We have some experimental things in the car, we have been spending out time on trying to get some data.
"We sacrificed some runs to [get to] know the car and prepare some tests for the future but it's looking quite good. It's looking quite good."
The teams now have a five-day break before returning to the Circuit de Catalunya for the final four-day test.
"[We need to focus on] everything, especially more on the set-up," Maldonado added.
"We didn't try different try different set-ups here because it was very important to put mileage on the car. But even then we had a reasonable set-up on the car which was not bad. We can improve it still, there is a lot of margin, and next week we will push in this direction."