Former world champion Lewis Hamilton exited his eye-catching new McLaren-Mercedes MP4-25 'smiling' after his first day of 2010 pre-season testing in Valencia yesterday (Tuesday), professing that the car is 'night-and-day' compared to its predecessor and quipping that 'it's nice not to be last'.

That, of course, alludes to the fact that the underperforming 2009 MP4-24 model begin life woefully off the pace - to the tune of a gaping three seconds during winter testing - and it took the entire first half of the campaign to turn things around and eventually develop it into a race-winner, dashing Hamilton's hopes of defending his hard-fought drivers' title.

With its successor, the British star is positive, McLaren will be in far better shape to hit the ground running - and challenge right at the front from the moment the starting lights go out in Bahrain in five-and-a-half weeks' time.

"It was a night-and-day feeling compared to the first lap on the first test day in 2009," the 25-year-old told reporters after winding up third-quickest, just over half a second adrift of the outright pace and behind only Ferrari's Felipe Massa and Sauber new boy Kamui Kobayashi following 108 laps around the Circuit Ricardo Tormo. "[It was] a positive feeling - exactly what I could have wanted from a first day.

"It's gone well. We got in and it felt good; I got out smiling. All the problems I had generally with the last car I don't have with this one, but there are still a lot of areas we can improve on. The Ferrari seems very quick, and so does the Sauber, but we don't know what fuel loads everyone else was on. We felt quite comfortable in what we were doing, but there is obviously quite a bit of time we need to find.

"I've kept a close eye on the development of this car. [With] the results we got at the end of 2009, seeing the car evolve and having input into it, I was excited to get in the car to see what parts we had improved. Hopefully we have got rid of a lot of the bugs that we had in the previous car, and we're going to make progress from here to the first race. The encouraging thing is the reliability; we've not really had many problems, so that's a bonus for us.

"[Running with a heavier fuel load] doesn't feel very different to me, to be quite honest. The only reason I say that is just that the car feels quite comfortable with that fuel load. I'm looking forward to the next couple of tests we have, just to get some more running, more long runs and to see really the behaviour with the tyres.

"I've seen just how much effort and attention has gone into making this car what it is. We've been pushing like crazy to find the performance, and the result is something very special and very uncompromising. It's too early days to really say, but I do feel this car is a huge improvement from the beginning of 2009 - and therefore we're not two or three seconds behind! We're not last, which is a nice feeling!"

New team-mate and reigning F1 World Champion Jenson Button - the man who stole away the crown and coveted number one last year that Hamilton is so desperate to reclaim twelve months on - will take over in the cockpit for the third and final day today (Wednesday). The Stevenage-born ace acknowledged that the home-grown duo will need to work together well over the coming months if they are to bring the all-important drivers' and constructors' trophies back to Woking come season's end.

"Both Jenson and I are world champions," the eleven-time grand prix-winner affirmed, "and we both want to add to the team's incredible winning legacy. I think a strong driver line-up will be very important this year, as there are a lot of very competitive teams and drivers - and the stronger we can be, the better chance we'll have of winning races. We all understand that.

"Obviously, I want to win the drivers' world championship, that's clear - but just as importantly, I want to help the team win the constructors' world championship. I think it's set to be a great year for Formula 1 - it should be brilliant!"