Hamilton has won 51 of the past 100 grands prix for Mercedes and four of the past five championships.
He said: "We're free to race like every single year so that was even said at the beginning of... back at the factory and it's repeated today and that's how I like it".
If Ferrari's pace in Barcelona translates to race day, they could pick up an additional 21 points this season.
Asked if Ferrari are in a better situation now than they were 12 months ago, the 31-year-old told a press conference: "Yeah quite frankly because last year's winter testing didn't go well for us".
Sebastian Vettel now has the support he needs to win the title for Ferrari.
In eight of the last 19 seasons, the victor of the opening Grand Prix has not gone on to become champion.
"The auto will be fresher here [in Australia]", Hamilton said of his W10 Mercedes in spite of the lack of updates post-testing.
"The name of this year's auto, the SF90, is already a celebration of this anniversary and, on top of that (we have) made a decision to honour this achievement in an even more evident manner in Melbourne", Ferrari said in a statement.
"This is going to be the toughest battle yet". We have experience, it's no coincidence that we are world champions so we have to be diligent and stay balanced.' He added: 'But as a driver for sure I have to figure out how can I pull more out, which I don't have the current answer for'.
Last season Hamilton dominated the show after bagging 11 of the final 19 races.
Toro Rosso rookie Alex Albon, meanwhile, became the first driver to hit the barriers in the new season when he span out mid-way through the session.
Vettel is keen on having some fun. The 29-year-old Finn is now entering his third year with the world champions and says it is time to be more selfish in order to achieve his career goal of winning the world championship.
"In the end we are racing for Ferrari and we will try to get Ferrari back to where we've been trying to get it back to for the past few years".