Happy Jenson Button reckons McLaren in much better shape than 12 months ago

A year ago McLaren endured a disastrous winter and had to embark on a major last-gasp redesign, but although Button was only eighth-fastest today, he was very pleased with the MP4-27's behaviour.

"There are no niggly areas with the car, which is nice," he said. "It is quite different to last year. So, I am happy.

"It is still a starting point and we didn't do any set-up work today to improve the balance, and you will never start off with a perfect car. You are just putting some miles on it really. But, I am very happy in the car."

Button added that the difference between today's running and the start to McLaren's 2011 build-up was dramatic.

"It is very different," he said. "When we could do laps [in 2011 testing], for one lap it felt like you could get something out of it. But then the degradation was massive. And we knew that from the word go, so yes it does feel very different to testing last year - which is a good thing really because it is not like we can just stick on an exhaust that gives us two seconds at the first race [this year.]"

Button admitted he had expected the ban on exhaust-blown diffusers to have had a greater effect on the 2012 cars' performance and handling than seems to be the case.

"I was surprised," he said. "I would have thought we would have had more issues under braking because the downforce that the top teams were producing from the blown diffuser last year was staggering and to lose that much, you would think that you would struggle, and the difference between on throttle and off throttle you think would be massive but it is not such an issue.

"I suppose you balance whatever grip you have, and that is what we have done. I don't feel it is a massive issue. It is not something I would point at and say that is a weakness of the car."

He also believes 2012 will see much closer competition than last season.

"The regulations are very different now, so I think you will see the cars a lot more bunched up this season, especially at the start of the year," Button added.

"When racing gets underway and you are always improving the car during the season then the field will split a little more but at the start of the year I think you are going to have a lot of cars that are within a few tenths.

"It is great, great for the sport - it just makes it more complicated and difficult for us."

Button will continue testing the MP4-27 tomorrow before Lewis Hamilton takes over on Thursday.