Seven-times world champion Hamilton, who leaves the Silver Arrows for Ferrari at the end of the season, has been frustrated by reliability issues in recent years and retired from the last race in Melbourne after engine failure.
"It’s been night and day difference over the weekend so far, just in terms of how comfortable I felt in the car," said Hamilton, who qualified in seventh, 0.569 seconds behind pace-setter Max Verstappen.
"The car’s been much nicer to drive this weekend and particularly at a track like this where you need a nice balance, this is the nicest it’s felt over the last three years," he said.
Hamilton also out-qualified his teammate George Russell for the first time this season, with Russell finishing in ninth.
But the Briton, who won six of his seven world titles with Mercedes, the latest in 2020, said they will need more performance to compete with Red Bull who have dominated the sport in recent years.
"It’s been really, really hard to get the set-up right and it's been so far out each time. In some places, it just felt like nothing we could do," Hamilton said.
"This weekend it’s much more in the sweet spot so I hope that continues in the following races and then we’ve just got to add performance."
