The former world champion is already tipped to be battling near the front this year following some impressive runs for his new W04 in testing.
But despite Mercedes' rivals' expectations, Hamilton underlined that he feels no pressure over 2013.
"I don't think there are any expectations, no," said Hamilton, who saw his Mercedes team round off winter testing with the fastest times at Barcelona.
"If anything, I feel like I have a free ticket. It's a year where we know we may not have the best package, but it's a challenge for me.
"And I don't think that there's pressure from outside for me to do anything with that challenge. It's just more for me to enjoy working with the team and improving.
"I think the pressure is more on the other guys, who had great cars and were evolved into this year's car. They have the pressure to go and compete and perform. For us, we only have everything to gain."
Hamilton's rivals are not convinced by his downbeat assessment of where Mercedes stands.
Ferrari's Felipe Massa for one is convinced that Hamilton will be a contender for the championship in 2013.
"Lewis is a driver who has always shown he can fight for the championship," said Massa, at a media event with Santander in Barcelona on Monday.
"He is very, very quick, and he has always proven that when he has a competitive car, he is going to be fighting for the wins and for the championship.
"We have to look at everything he will have available to get those results, and he will certainly fight for the championship and victories, as we have seen him do in other cars before."