Michael Schumacher declared himself happy with the 2012 Mercedes AMG Petronas F1 W03 after a productive day's testing in Spain.
The new car made its official debut on Tuesday at the Circuit de Catalunya in Barcelona.
After an early morning unveiling in the pit lane by Schumacher and his teammate Nico Rosberg, the seven-time world champion took the wheel for the day's running.
A smooth morning session enabled the team to begin set-up comparisons with the new chassis, before a hydraulic problem identified during the afternoon session brought an early end to the planned programme.
Schumacher completed 51 laps in all, taking the F1 W03's total mileage to 782 km to date.
Afterwards he reported: "My initial feelings with our new car are certainly good. I'm happy with the different evaluations that we have done over the last week, but obviously with the rule changes, we won't know more until later.
"It's certainly an improvement and we have worked hard on the areas we had defined last year.
"The aerodynamics figures look good so I'm not worried about the shape of the nose! Even though we had the hydraulic problem today, I'm pleased with all the mileage we have achieved so far with the new car."
Rosberg will take over the testing programme on Wednesday and Friday, with Schumacher back in the car on Thursday.
