Jenson Button has said that the new updates on the McLaren car are a definite improvement on last year's model.
The 2009 world champion got to grips with the new MP4-27 at the Circuit de Catalunya, despite rain curtailing any further improvements to the hydraulics.
Button, who finished the penultimate day of the final pre-season test second fastest behind Sauber's Sergio Perez, said that he is a lot happier this year.
"I'm just a lot happier with everything. We're not running round, scratching our heads and wondering what we've done wrong," said Button. "Last year we had problems with the exhausts in terms of cracking and we also had the problem that we just weren't very fast - even when the exhaust did work.
"It was a very difficult winter and you just can't do any testing. If you have one reliability issue, you can't take all the other parts of the car to their life - so you have other reliability issues and you worry about that at the first race.
"I'm much happier with where we are but you always want more testing, especially if something goes wrong like today."
The 32-year-old will not be getting back in the cockpit again until opening practice for the Australian Grand Prix in Melbourne.
