Both Hamilton and his teammate Jenson Button voiced their concerns throughout preseason that the car was not as good as they hoped it would be.
Although lacking in pace, of greater concern was the reliability as the MP4-26 failed to complete a single race distance during testing due to a variety of issues.
Martin Whitmarsh, the Team principal, has since claimed the car has had a radical revamp they hope will claw back the second gap to their rivals.
The clock is ticking for McLaren, with first practice for Sunday's Australian Grand Prix just two days away.
"We can't hide the fact testing has been tougher than we expected," said the 2008 world champion Hamilton.
"Our test mileage hasn't been as high as our rivals, nor have we had the outright pace of the fastest cars.
"Still, I have a good feeling with the car, and I understand we'll be making further performance steps ahead of this opening race.
"Nevertheless, we know we go to Melbourne ready for battle. Some teams are extremely well prepared, both from a pace and reliability point of view.
"But that can sometimes count for little in the unpredictable and somewhat chaotic opening races where it's equally vital just to take points home.
"I strongly believe that, while our preparations haven't gone as smoothly as we'd have liked, we'll be arriving in Melbourne with everything finally meshing together — and that makes me really excited."
Nothing would give Hamilton greater pleasure than a reasonable result, while at the same time staying out of trouble both on and off the track.
Melbourne has been a far from pleasant place to visit for Hamilton these past two years, although he claims his stock has risen with the Australian public.
In 2009, in his first race as defending world champion, Hamilton was caught lying to stewards in a post-grand prix investigation which resulted in him being stripped of his third place.
A year later and Hamilton's antics extended to outside the circuit as he was caught "hooning" or burning rubber by the Melbourne police in his hired Mercedes which was later impounded, earning the Briton a £280 (Dh1,682) fine.
Eager for the quiet life on this occasion he said: "This year should be a little more dull for you guys [the media] — hopefully.
"Outside of the track I won't be doing any driving. I'll be keeping to myself in the hotel."
Although eager to stay away from the long arm of the law, Hamilton knows he has many fans on his side.
"I get really good support. Surprisingly people really like me over there," said Hamilton.
"I've always had decent support when I go to Australia, and I've met a lot of Australians since.
"I think they can relate to me a little bit more, that I'm not a robot, saying 'Ah, you're like one of us. Nice to meet you.'"