Whilst it is still far too early to be making predictions, little by little clues are beginning to emerge as to who should be hot and who might not come Melbourne.

Whilst it has yet to top the timesheets, Mercedes is clearly in a class of its own, and both Lewis Hamilton and Nico Rosberg can expect to receive a few 'Driver of the Day' awards over the coming season.

With the silver cars yet to resort to the softer compounds, having reveald that it will stick with mediums for the remainder of the test, the opposition is grabbing the headlines whilst it can.

Though he never eclipsed Sebastian Vettel's best, Nico Hulkenberg demonstrated, as did his teammate yesterday, that the Force India VJM09 has pace and reliability, and should be in good shape to defend its fifth place in the standings, if not challenge for fourth.

Second place for Romain Grosjean should also give Haas a huge boost, even if the opposition has yet to turn up the wick.

Having lost most of the morning with a fuel supply system issues, Kimi Raikkonen put the Ferrari through its paces in the afternoon, the Finn, encouragingly, the quickest man on the medium rubber.

Though fourth on the timesheets, Kevin Magnussen suffered a late issue which makes clear that Renault still has a long way to go in terms of reliability, though the Dane was one of only four drivers to exceed 100 laps.

In a change to its programme, Mercedes, insisting it wants its drivers "fresh" for Melbourne, ran Rosberg in the morning and Hamilton in the afternoon, the pair putting another 162 laps on the scoreboard. With the silver arrows yet to miss a beat, the opposition must be dreading the moment either Nico or Lewis finally do slap on a set of purple ultras.

Following a few 'moment's on Monday and Tuesday, Toro Rosso finally came good, Carlos Sainz completing 161 laps and posting the sixth best time to boot. The fact that this came on the medium rubber will surely inspire further confidence in the Faenza squad.

Following yesterday's shoot-out between Daniel Ricciardo and Vettel, it was an altogether more discreet 2016 debut for Daniil Kvyat, as a technical problem that surfaced yesterday made an unwelcome return.

Felipe Massa had a low key day in the Williams, whilst Jenson Button lost most of the afternoon's running following a hydraulic leak.

Propping up the timesheets, and the cause of one of the day's (two) red flags, was Rio Haryanto in the Manor, the Indonesian driver completing 78 laps.

"A positive day for me," beamed Hulkenberg, "and I've come away with some good first impressions as we continue to learn about this car.

"We tried quite a lot of things today," he continued, "and although we need to do some more fine-tuning, it does feel like we are moving in the right direction. The important thing is that we are getting lots of laps under our belt at this early stage and we are able to start exploring different set-ups. Melbourne is not far away, but it feels like we are on schedule and days like this are very encouraging. You never know what the other teams are doing so we're just focusing on ourselves and working hard."

"Nico's first day saw a continuation of data gathering to help with our understanding of the VJM09, as well as further car sign-off tests," added Chief Race Engineer, Tom McCullough. "The afternoon allowed a chance for Nico and his engineers to carry on with set-up adjustments and we made some good progress as the day unfolded. Nico evaluated the medium, soft and supersoft tyre compounds, and we managed some long runs towards the end of the day. We had a few small 'new car' problems that required attention in the garage and ultimately cost us some track, but we still ended the day just shy of 100 laps."

Five minutes after the lights went green, Romain Grosjean wheeled the VF16 out for an installation lap. It was a low-key beginning to a successful day for the new kids on the block.

Nine runs consisting of five laps or more were made, with the longest being a 12-lap stint at the very end of the day. It's there where Grosjean netted his fastest lap – a 1:25.874 time on his 71st circuit that put him second overall.

Grosjean ran the Pirelli medium tire for most of the day, switching to the softs for his final, two multi-lap runs.

In all, he logged 82 laps, bringing Haas' three-day total to 192 laps.

"The morning went without any problems," said Grosjean. "It was a really good morning. After lunch, we had a software glitch that cost us two small runs, but once we sorted that we were able to do some more mileage. The idea is to see how far the parts can go and which ones will be the first to go, so we did a good job in that aspect. We did the most laps so far in this test, so that's good. Generally, I'm very happy with the car, very positive. I like driving it. The guys are doing a good job. We found some setup improvements, so that's very positive for everyone."

"It was a very constructive day," added Guenther Steiner. "We are pretty happy on what we achieved. We are getting laps together and, for sure, experienced some little problems, but that's why we're here. The team seems to be gelling and we're working hard. There's a very good atmosphere in the team and we're making progress."

"The atmosphere in the team is quite nice even if, honestly, we're still working on different things and still find something new to work on," said Kimi Raikkonen, "but I am sure it's going to be a better car than last year's.

"There are always small changes between one car and another, they are never the same. We had improvements in many areas from the past season. These are early days, especially for me with this car. We are happy so far, even if we know that there are still a lot of things to do. There were tricky things and it takes time to fix them. It was painful losing time today, but we always try to do our best. There are always mistakes but we always want to improve and learn from them."

Kevin Magnussen made his Renault debut, completing 111 laps with a best time of 1:26.014, the fourth fastest of the day.

"It's fantastic to get back in a Formula 1 car after eleven months away," admitted the Dane. "Everything felt good straight away and it was great to be working with the team for the first time behind the wheel. We completed a lot of laps which is a real positive and I can't wait to jump in the car tomorrow and continue today's work."

"A much better day for us in terms of reliability," added Trackside Operations Director, Alan Permane, "so we were able to run through a bigger programme including set-up and aero work as well as longer high fuel runs. This leaves us with a lot of data to work on with overnight. It was our first day with Kevin and he was very quickly into the groove so looks to be a very strong asset for the season ahead. We did have a water leak during the day, which was easily identified and diagnosed. We're optimistic for another positive day tomorrow."

In a change to the original run plan, Rosberg and Hamilton split driving duties. With the unprecedented mileage levels seen thus far in Barcelona, the intention is to keep both drivers in top shape. This strategy of alternating them will therefore continue throughout the remaining 2016 pre-season tests.

Rosberg emerged for his first run as the track opened at 09:00, completing 74 laps before the hour-long lunch break at 13:00. Hamilton completed a further 88 laps in the afternoon.

Today's programme focused on setup evaluation, aerodynamic data analysis and race simulation work - including starts and pit stops.

"That was another very valuable day for us," said Rosberg. "It's amazing to see that the car is already so reliable and we started trying some basic set up changes this morning too.

"It was good to split the time on track with Lewis. The car is able to do so many laps, so I think it's probably a more effective way of doing things. Two drivers doing half days will do better work compared to 160 or 170 laps from one person. We want to get the maximum out of the very few testing days we have this year, so to me it makes perfect sense.

"I heard about the new qualifying format for 2017 today. I hope it stays simple and clear for the fans, so we'll see how that works out. But, in general, it's definitely important that we rethink the sport and try to make it better from time to time, so I'm open to any improvements."

"It felt quite long out there today," added Hamilton, "even though it was only the afternoon session! We'd spoken about splitting the driving beforehand, so it wasn't a surprise. I was happy to do full days - but they are long days, so the team felt it best to mix things up to keep us both fresh. I feel great now - but yesterday I was a bit sore. It's a bit like going to the gym when you haven't been for ages. If you do a hard workout straight away, you'll be in pain afterwards. For your neck in particular, it doesn't matter how hard you train during the winter, driving just hits it in a different way that you can't really simulate. It is quite tedious, too, going round and round all day. It's not like a race, where you've got a strategy and you're competing - fighting the clock and your opponents. But testing never has been the most exciting. I think in my younger days, back in Formula Renault for example, it was a big buzz. But by the time you've spent ten years in F1, it just becomes the norm. It's quite cool being out on track with the other new cars. Your gut reaction is to try to get close and see how they perform through the corners and along the straights. But that's a waste of time, really, so you have to resist! In any case, we've had a great start to testing as a team so far. The car feels very much like last year's and we've done plenty of laps, so let's hope it continues with a strong end to the week tomorrow."

"A quite satisfying day today," said Toro Rosso Chief Engineer, Phil Charles, "our primary target this week is to get mileage on our new car and really push the reliability up, so completing 161 laps today is an excellent result.

"The other main positive from today is that since Carlos ran on Day 1, we are now quite happy on Day 3 to hear him say he has felt an improvement from then: Along with several new parts having arrived from the factory, a bit more running has helped us set the car a bit more around him. A happy driver is definitely a good thing!

"In terms of the program, we certainly ticked-off most of our requests, completing plenty of laps, doing some more cooling work, a couple of set-up items and in the afternoon we were lucky enough to complete our first race sim, which is really good to get under our belts early on. Overall a very good day and Carlos has jumped out of the car looking very fresh after 161 laps, so maybe we should target even more laps with him at T02!"

"A good day of testing," said Sainz. "We managed to complete the full run plan that we had set for today and I'm very happy with that. We managed to be out on track most of the day, completing 161 laps and adding plenty of mileage to the team's tally, which is what we came here to do.

"I'm feeling great," he added. "Obviously to do so many laps - over two race distances - after two months without driving is a lot for the body, but the good thing is that I managed to do them and that I am fit. All in all, a very productive day, the team is doing a great job and we just need to carry on like this."