The 2014 Formula 1 season burst into life today, with free practice at Albert Park giving us our first insight into the pace and potential of MP4-29, which performed reliably throughout the day, notching up 115 laps.
Kevin's run programme was designed to give him as much track time as possible. As a rookie, he faced the difficult challenge of getting to grips with a brand-new circuit while simultaneously learning how best to use the car and its systems across a race distance.
For Jenson, who has won the Australian Grand Prix three times, and who knows this circuit very well, the day was about understanding the car and its systems. Principally, his focus was on monitoring tyre degradation and the amount of fuel-saving required around a track that is particularly high in terms of fuel consumption.
Both drivers were happy with the progress made today, although they agree that there's still more work needed to get the car fully balanced for the remainder of the weekend.
Jenson Button: "I always enjoy this circuit - it's quite bumpy and there's no room for error, which always makes it fun! In all honesty, these cars work better around here than I'd imagined, but Sunday's race will be very different. The long runs weren't as much fun as I'd hoped they'd be, because you need to save a lot of fuel. And that's such a different way of driving - you're lifting off very early, and there's lots of lift-and-coasting around the lap. On low fuel, however, it's really fun to drive.
"Our car balance isn't quite there yet - we're still struggling a little in the high-speed corners. In the low-speed corners, we're looking reasonable, and all our electronics are working well. I don't think our outright pace is quite as good as it looks on the time sheets, but we've got a good understanding of the car and overall I'd say we're looking okay."
Kevin Magnussen: "For me, today was about getting used to everything; taking it step by step, and making sure I was moving forwards and learning all the time.
"I've watched Formula 1 cars on this circuit on TV for many years, so it's strange to be driving here at last. But it was a good feeling to be out there on the track - I really enjoyed it.
"There's definitely an element of learning for me here this weekend, so it's good to have Jenson alongside me. He's so experienced, and of course he's very strong around here. I can learn a lot from him. The rest of the weekend is going to be really interesting.
"Lastly, I'm happy that we've got a lot of good data to go through. So now I've got to sit down and work hard with my engineers and the rest of the team to develop the car ahead of qualifying tomorrow. We think we know where to take the car from here, but as I say there's still plenty of work for us to do."
Eric Boullier, Racing director: "Jenson, as usual, demonstrated all the flair and experience that have taken him to three grand prix victories here at Albert Park [2009, 2010 and 2012]. As ever, his feedback has been extremely valuable, and he's provided the engineers with a great deal of useful info ahead of tomorrow's sessions.
"As you'd expect, Kevin faces a steeper learning curve, but he developed quickly and assuredly throughout the day. It's never easy to learn a new circuit as well as the intricacies of a new car, in just a few hours, but he did a great job.
"Moreover, and encouragingly, he appreciates that there's more to come - particularly when attempting to draw the full potential from a set of new Option tyres - but he'll get there. It's just a question of gaining more experience. I've been impressed by his progress - both on the track and off it, where he fully appreciates the need to work through the day's data with his engineers.
"Today was always going to be interesting. Several teams look faster and more competitive than they did in winter testing, and the sharp end of the field looks very competitive.
"Our aim will be to continue the learning we started at the beginning of the year, and to try our best to get two healthy cars to the finish line on Sunday. In these early races, it may be possible to earn extra points from reliability alone - and that's why optimising our car's reliability remains our principal aim for this weekend.
"To sum up, it's been a solid start, but the key fact I want to emphasise is that there's plenty more to come - both this weekend, and for the forthcoming races."
Check out our Friday gallery, here.