Lewis Hamilton led the way in both free practice sessions, culminating in a fastest time of 1:23.620 – 0.2 seconds faster than his pole position time at last year’s Melbourne race and more than half a second quicker than anyone else.
“It was 99% perfect,” said Hamilton. “We’ve shown good form so far on both the long and short runs, and we got every lap done that we wanted to.”
“We had a very good day overall,” agreed Mercedes team boss Toto Wolff. “For the team it was one of the better Fridays.
“After having some question marks over testing in Barcelona, it was good to bounce back in that way.”
More concerning than the gap between Mercedes and the field, however, was the distance between Hamilton and his new teammate, Valtteri Bottas.
Bottas was off the Briton’s pace in both sessions to the tune of almost 0.6 seconds, a worrying sign for reigning world champion Nico Rosberg’s replacement.
“I definitely feel like I can make a step forward tomorrow,” said the Finn. “It’ll be a busy evening for us tonight looking through all the data to see where we can improve.
“It’s only practice, so tomorrow we’ll find out exactly where we are.”
While Mercedes’s practice advantage was indisputable, the competition behind the Silver Arrows was less clear cut, with Red Bull Racing and Ferrari taking it on terms to be the next-best team.
Red Bull Racing’s Daniel Ricciardo sat 0.6 seconds behind Hamilton in third in the afternoon but fell back to more than a second behind in the evening, whereas Ferrari bounced from 1.1 seconds off the pace to being second best and half a second behind by the end of the day.
“I think we can still get more out of it,” Ricciardo said. “I think this morning was promising, and we tried a few things this afternoon and it’s fair to say they didn’t work as much as we’d have liked.
“We’ll probably go back a bit and then understand what we can do better for tomorrow.”
The Australian wasn’t so pessimistic to suggest Red Bull Racing was out of the running, but did say a fight at the front would rely on Hamilton failing to string together a perfect lap.
“I think Mercedes sure is quick, but it’s more Lewis than Valtteri – Valtteri at the moment looks like he’s in our group, the group with Ferrari.”
Vettel, who has widely tipped ahead of the grand prix to be the man to take the title fight Hamilton with his Ferrari SF70H, played down his team’s distance from the dominant Hamilton.
°People from outside always make up their own opinion — obviously we’ve been very happy at testing, the times looked good, but it doesn’t mean anything.
“You come here, that’s what matters.
“I think overall it’s been okay. The car doesn’t yet feel as good as it should and as it can, so I’m confident we can do something.”
The year’s first two practice sessions proved eventful despite limited running taking place during the first 90-minute session.
This season’s cars are billed as amongst the fastest ever, but drivers had to find the downforce limit around the slippery street circuit.
Jolyon Palmer exceeded the limits of his new Renault at the final turn, smashing the rear of his car against the barrier and ending his evening early.
Max Verstappen and Marcus Ericsson both had excursions on to the gravel – the former escaped with floor damage, the latter beached himself with just a handful of minutes left to run in the day.
Practice resumes on Saturday afternoon ahead of evening qualifying for the 2017 Formula One Australian Grand Prix.