Even before an engine has been started in anger in the new season, the tension between former team-mates Jenson Button and Lewis Hamilton is growing.
The main focus will have been on Melbourne's Albert Park for the first official practice sessions, but Britain's top two drivers are embroiled in a war of words about Hamilton's time at McLaren.
Since moving to Mercedes at the start of the year, Hamilton has claimed he has been revelling in the freedoms that were not granted him at McLaren, where he spent 13 years, the last six of those in Formula One.
Earlier this week, he said: "I have come from a place with a lot of control, a really controlled environment where you are restricted to do and say what you are told."
Those comments left Button bemused and he was quick to counter the claim – and launch a thinly-veiled criticism of his old rival. "I was very surprised to hear that," he said. "The freedom you have in this team is phenomenal, and that doesn't just go for me.
"Mercedes can use revenue from their road car sales to fund their team, but at McLaren we have to work harder to cultivate and retain sponsors.
"Here you have to work harder. Initially, when I came to the team, it was a shock. You learn to understand and to adapt, that's the job. But in terms of what you can do as a driver, and the way a driver can help the development of a car, this team is amazing. Whatever your issues are you get help.
"I've heard so many rumours – and not from Lewis as such – and read so much about the way this team is, and it's so far from the truth."
Much has been made of the rivalry between Hamilton and Button despite the Mercedes driver saying recently that his former team-mate gets little of his attention. Hamilton claims he is more excited about his battle with Fernando Alonso, whom he clearly regards as his greatest rival.
However, Button's view is different. He said: "In F1 there's no place to be friendly with your greatest rival. Now that we aren't team-mates, we can be more ruthless in our on-track battles. It will be interesting to see how we get on. We had to hold back as team-mates, but it becomes very different when the other person is in a different camp."
Button claimed few accurate conclusions can be drawn about the strength of teams' cars from pre-season testing, a view shared by many in the paddock. He added: "Last year the form from testing proved completely wrong at the first race, and though Mercedes have been very fast over one lap this year, it will be very different today and they probably won't set pole position and win every race. I'm sure, for example, that Red Bull aren't really 2.5 seconds slower, as they were in testing."
Accurate calculation of rivals' speed was rendered difficult throughout testing by factors such as fuel load, with some cars running heavier than others. "The way in which Pirelli's new tyres degrade is also going to be crucial," Button said. "That has added to the difficulty we have all had in calculating where we stand against each other. Today we will at least start to get some real answers."
Mercedes' Nico Rosberg explained: "The new Pirellis are very different to their 2012 tyres. They slide at a certain angle and that's where the grip is best, but they also degrade strongly and it's a massive technical challenge for all of us to create a car that has less tyre degradation than everyone else. Last year that was one of our big weaknesses, but this year we have really improved."
After a difficult winter, McLaren believe that they will qualify here behind the Mercedes, driven by Rosberg and their former star Hamilton, while the Briton is in no doubt that Ferrari will be the strongest.
One of their drivers, Alonso, has said this year's Ferrari is "200 times" better than its predecessor, with which he fought Sebastian Vettel all the way for the 2012 crown. Now he has his sights set on matching the German's three titles and has even greater motivation after the pain of that narrow defeat.
"It's not difficult to start better than last year because it was difficult to start any worse," Alonso said. "We got a little bit too far behind. The winter has been much better than last year, understanding the car and working with it and getting the results we more or less expect.
"That will give us much more confidence and optimism to start the season, but who knows? I think it will be a very interesting championship, with a very challenging first part in Australia and Malaysia. Difficult circuits, difficult weather as well – changeable. So we need to start on the right foot and hopefully score some good points."
Vettel, meanwhile, was as frustrated as anyone else by tyre degradation on his Red Bull in testing, but remains motivated to win a fourth successive championship. "If there is a secret I think it's not to think about what happened in the last three years," he admitted.
"I think the first title was very, very special. After that I don't think you have that pressure any more. You've proved to yourself that you can do it. After that we had two fantastic years again, which were very different to each other. But you probably don't think about what happened last year or the last three years.
"We are here, we have zero points on our side at the moment, the same as everyone else. So everyone has the same opportunities. The cars didn't really change. Last year we saw it was very close, so I don't expect it to be any different. If anything, it will be maybe a little bit tighter. So it will be crucial to make the most out of every single race. In terms of motivation… it was a long flight but I'm happy to be here now and very pleased to start again."
The mood music coming from Hamilton suggests that he is also pleased to be starting again and re-engaging with his rivals. He has also highlighted the possibility of his new car not yet being up to scratch but the Mercedes team director, Toto Wolff, has made their targets quite clear. Repeating last year's total of one victory would not do. "We need more. And regular results," he said. "It is about having a steady season and being among the lead teams throughout."