In his third year in F1, Perez has been plucked from Sauber - where he scored three underdog podiums in 2012 - to replace 2008 world champion Lewis Hamilton alongside '09 title-winner Jenson Button.
Having now completed three test sessions with McLaren, Perez said he had found the team far less 'cold' than its reputation, and that this relationship gave him confidence that he could live up to expectations.
"I enjoy every single day I spend at the factory with my team and I'm enjoying life a lot," he said.
"First of all I'm really enjoying my work and I'm very motivated. I think if we keep doing the same, we will be fighting for big things this year.
"The atmosphere in the team is great. Everything is so united. From the outside it might look a very cold team but it's a great team, very happy and I'm enjoying every day."
Perez admitted that McLaren had inspired him to sharpen his approach and work harder.
"I enjoyed my time at Sauber as well but here I really enjoy myself much more," he said.
"When you are in a top team, you have different targets: you're fighting to win the championship, you're aiming to win races.
"So this really changes your approach and your motivation, and it definitely makes you work harder."
Although Perez said he had not accomplished everything he had wanted to in testing, he was content with his level of readiness.
"It's just a bit disappointing not to get everything, but it's normal, you will not get everything done for the first race," he said.
"The most important thing is taking every opportunity you have to maximise work with the team, and that's what we've been doing.
"We have done an extremely good job in this pre-season."
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