Mercedes emerged as a contender for race victories during the final week of Barcelona testing.
Despite this boost, Hamilton says there can be let up in the quest to get in the best shape possible for Melbourne.
"We need to keep pushing on," said Hamilton, who ended the penultimate day of testing at the top of the timesheets.
"I've got to apply the pressure. So has Ross [Brawn]; so has Toto [Wolff]. We've got to continue to apply the pressure in the most important areas.
"I've got to explain to the team here where the car is weak; where we can improve. Then next week, when we are at the factory, we'll do some simulator running and then we'll try to improve the simulator.
"We also need to give the guys back feedback about the windtunnel, and they're also getting questions about what's going on with the car.
"Then, when we get our next upgrades, if they say it's coming for China, we want it to be on for Malaysia. We have to apply the pressure all the time."
Although Mercedes' rivals are in no doubt about the strengths of German car manufacturer, Hamilton has been eager to keep his feet on the ground
"I won't say I'm completely satisfied," said Hamilton about Mercedes' winter. "If I felt that I had a rocket underneath me, then maybe [I would be], but I feel like I have a good foundation to work on.
"I think we've had a step forward with our upgrade, but everyone would have made an upgrade for here, and I think it's just a small step forward and we need more."
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