Though there is still a long, long way to go before the cars head out on to the grid in Melbourne, a quick glimpse at the timesheets following today's opening test should send shivers down a few spines.

It won't only be rival teams and drivers that will recoil at the sight of world champion Lewis Hamilton completing 156 trouble-free laps - thereby exceeding the mileage completed on the first days of testing in 2015 - but broadcasters, sponsors and just about everyone else who want to see a real battle for the 2016 titles.

Whilst the day went without a hint of a glitch for Mercedes, a number of other teams weren't so lucky, with Renault having a difficult return, Haas suffering a front wing failure and Toro Rosso bringing its first day to an early conclusion.

The day began with a flurry of unveilings, a quick smile for the cameras and then down to work on a track still damp following overnight rain.

The front wing failure Romain Grosjean suffered on the Haas brought about the only red flag of the day, a day when the eleven drivers on duty completed 799 laps (2310 miles).

Hamilton emerged for his first run as the track opened at 09:00, completing 66 laps before the lunch break at 13:00 and a further 90 laps before the flag dropped at 18:00.

Today's programme focused on accumulating mileage with the W07, including setup evaluation and assessment of the 2016 Pirelli tyres.

"It's good to be back," beamed the world champion. "It really had felt like a while - but now it feels like home already. I'm glad to see I can still drive!

"The car has been great so far," he continued. "It's very similar to last year's - which is a good thing, as it gives us a great foundation to work from.

"The key is to get as much mileage as possible in the short time we now have for testing and we've made a fantastic start. The team has done an incredible job to get the car running the way it has - completing so many laps with no real problems. That's seriously impressive on the first day, so fingers crossed it continues.

"The tyres feel a little different and we'll work to understand them better in the coming days. Barcelona is one of the best circuits to test a new car, too. It's got a wide range of corners and the weather's always good, so overall it's been the perfect way to kick off the year.

"Of course, it's still early days. It's hard to say how the others look at this point and we won't know how competitive we are until everyone really starts pushing. But we're not looking too bad, that's for sure. Every season you have to assume is going to be the toughest competition yet, so that's how I'm approaching it. I hope the Ferraris are up there with me and Nico this year, as that would be exciting for the fans and exciting for me too."

"The first impression is good," said Sebastian Vettel, who completed 69 laps as he focussed on aero testing and baseline setup, "I think the new car is a step forward.

"I felt confident enough, but we know there is still a lot of work in front of us," he admitted. "For sure there have been changes inside and outside the car. Laps times today are not important at all: they will be in a month's time at the Australian Grand Prix!

"It was good to have some laps, I would have liked to have some more but it is natural that when you have something new and things you want to check you are more conscious, so you stop to have a look at them, and unfortunately this all takes time.

Following the trials, threats and tribulations of last year, today wasn't too bad for Red Bull, Daniel Ricciardo posting a largely trouble-free 87 laps on his way to the third-fastest time.

Commenting on his first day behind the wheel of the new car, the Australian said: "That was pretty good. I think we had a few niggles but we still managed almost 90 laps. It was a day for testing reliability: for me, seeing how fit I am after a long off-season, and for the team seeing how the car is – where it's reliable and where not. It was important to get in some good 15-lap runs to make sure the car is not doing anything silly and we did that. Once we have that then we can find the pace, but reliability is the first thing you want.

"The car feels familiar, it doesn't feel strange and that's positive. I think last year we ended the season quite well, the car was good, and this feels similar. First impressions are positive but it's still too early to say much more. We had a good day and I'm ready for more."

"It was a very good first day at the office for us," added Head of Race Engineering, Guillaume Rocquelin. "The car build went according to plan, we had no major issues there and we made it out on track on time. We had a small issue in the morning but it was nothing serious, just something that had worked loose and which took a while to get to. But once we were up and running again, we managed to run very consistently, which is really all that you are looking for on the first day. If you get that then you can start working through the checklist of items you have to get ready for the start of the season.

"With just eight days of testing that's what this week and next will be all about – getting as prepared as possible for what will come. For Daniel, I think he was satisfied with how things went. There's obviously not much he can get from the car in terms of how it ultimately feels, so for him it's more about blowing off the dust and getting back into it and I think he enjoyed that. Today we chomped a good bit out of the workload and we'll hope for more of the same tomorrow."

"We had a slightly mixed day," declared Rod Nelson, Williams Chief Test & Support Engineer. "We had a few niggling little issues that kept us in the garage for longer than we wanted to be there, but we're still learning about the car so that's not unexpected and we were able to work through them to continue our programme.

"Valtteri has been complimentary about aspects of the FW38 which is good start," he added. "We are just building up our run lengths and doing our due diligence on reliability, and as the test goes on we'll feed in more and more performance items. Overall it is a reasonable start to pre-season testing for us.

"It's always very nice to be back in the car and it's nice to feel that we have made improvements," said Bottas, "but it is way too early to say anything more than that. We were focussing on different kinds of tests today with the chassis, and some aerodynamic tests so mainly longer runs. We had a few problems but that's testing, and hopefully we will have a clean run tomorrow. First impressions of the new car are good and I think we have fixed many issues from last year. However, like I said before, it's just too early to say where we are against the others.

The Force India VJM09 was one of several cars unveiled this morning, subsequently being put through its paces by Alfonso Celis, the team's development driver. The young Mexican completed 58 laps on his way to setting the fifth fastest time of the day. Sergio Perez will take over the cockpit of the VJM09 tomorrow.

"I'm feeling very happy with how things went today," said Celis. "The start of the day was special when we launched the VJM09 and it was a big honour to be the first to drive the car. It was only my second day in a Formula One car, but I was able to enjoy the experience more than last time because I knew what to expect and I had a bit more confidence.

"The car was perfect today and I want to say a big ‘well done' to everybody in the team for all their work over the winter to deliver this car. We managed to work through the whole plan with good reliability. I could not think of a better way to start the season and I'm really looking forward to getting back in the car on Thursday."

"We took a cautious approach to the start of the day due to the overnight rain with the track taking quite a while to dry out," admitted Chief Race Engineer, Tom McCullough. "When we did get out in the middle of the morning, Alfonso worked through a lot of the systems checks needed for a new car before we moved to an aero correlation programme with various test instrumentation fitted to the VJM09. The aero work took up most of the day and it required Alfonso to make frequent adjustments on the steering wheel to help with the data gathering.

"As first days with a new car go, today has been remarkably smooth and Alfonso has done an excellent job. His approach was very mature and he steadily built up his speed during the day. We look forward to working with him again on Thursday."

Jenson Button got into the cockpit of the McLaren MP4-31 for the first time. The primary focus for the Woking team was establishing the foundations required with a new car: ensuring systems were running correctly, tools were working properly, and data was being collected effectively.

Some necessary checks under the bodywork to investigate a few minor technical glitches caused a brief hiatus early on, but these were rectified quickly, and the Briton put 35 laps on the board in the morning session, just under what the team achieved over the first three days of testing in 2015.

The afternoon allowed the team to stretch the legs of the MP4-31 further, with the focus on pit-to-car communications and telemetry functionality, correlation of our new aerodynamic package, and power unit mode tests.

The weather was conducive to a productive day's running, starting cloudy and chilly but breaking for warm sunshine and blue sky for much of the afternoon.

Button completed 84 laps and executed a host of valuable evaluations of the new package, which gives the night-shift crew a good basis from which to build a detailed run programme for Fernando Alonso tomorrow.

"I've missed Formula 1 massively over the last few months," said Button, "it seems like the longest break I've ever had in my career - so it's great to be back, to be in the car, and get some laps under my belt.

"Today has been all about system checks and trying new things - there are lots of differences with this car, and with the engine. The stand-out thing that's been very positive today is the deployment: it's been very consistent throughout the day, we had no issues, and it was quite a bit better on long runs than last year. This is good, because it allows us to see other weaknesses in the car that we still need to improve.

"Overall, a good day actually and I'm reasonably happy. In terms of outright pace, who knows? We're not going out there to set a lap-time, we're focussing on checks and having the engineers talk to me, as there's so many different electronic things that we're trying out, which is very interesting."

"We completed five more laps today than we did in the first four days of testing last year, which is definitely an improvement! As long as we can see improvements, and the feeling of the car is good, it's something to build on."

"Today was a solid day," added Eric Boullier, "we got some good laps under our belt, which is encouraging for the first day of testing, and an improvement on last year.

"The first data we have gathered today from the car is positive, as there is clear correlation between the data from the factory and what we have seen on track. Today, just like the next few days, is testing, and we are focussing on just that: testing. It's imperative to complete all the necessary system checks, gather the required data and correlate the numbers with what we expected from our preparations over the winter.

"Overall, we are not in a position to build expectations - it's very early days - but before we think about performance we first need all the tools and data at our disposal. Today was a first step in the right direction, but there's a long road ahead, and we're taking it day by day."

"We are pleased to have a solid day's testing on our first day back," admitted Satoshi Nakamura, Honda R&D Co Ltd chief engineer. "With 84 laps of running, we were able to run through all the necessary power unit system checks, and complete the power unit's run programme for today.

"We had niggly sensor issues this morning, but we were able to rectify it quickly, and the long run stints in the afternoon helped us tweak and shape our deployment settings. The feedback received from Jenson today has been positive, so we believe that we are heading in the right direction. We look to continue our step-by-step progress tomorrow."

Toro Rosso opted to bring its day to an early conclusion, as chief engineer Phil Charles explained. "Overall, we are pleased with today after a late decision on our power unit and fast birth of our new car," he said. "So to get to this point and run the car relatively successfully straight away is very pleasing and everyone in the factory should be proud of the big efforts made so far.

"Carlos was quite positive on his initial feelings with the car. We completed our build-up runs in the morning and everything was progressing quite well, with a decent number of laps completed before the lunch break. Unfortunately, during one of the early runs this afternoon we saw something in the data that's a little bit strange in the gearbox oil system, so as a precaution we decided to stop the car. We will now take our time to understand it and hope for an even better day tomorrow."

"We were all obviously very much looking forward to today and it was a great achievement to drive out after not the easiest of winters," added Sainz. "The team has done a great effort and today was quite a decent first day. We managed to have a very clean morning and it was also being a smooth afternoon up until we suddenly had to stop the car… So we had to unfortunately call it a day, but up until then it was all going perfectly and I felt good in the car."

On a day which saw a number of cars unveiled for the first time, Sauber stuck with its 2015 chassis, the Swiss team launching its car at next week's test.

Marcus Ericsson completed 88 laps today on his way to posting the eighth best time of the day.

"It was a productive day," said Swede. "My last time in the car was a few month ago, so it was great to finally be back in it again. Even though it was the C34, we were focusing a lot on trying different things that we did not have the time for last year. We tested several set-ups on the car, and we will use some information from this for early work on the C35. It was an extensive programme from which we obtained interesting data to look into."

Manor's MRT05 made an impressive and striking debut, Pascal Wehrlein completing 54 laps of reliable running to end the day ninth on the timesheet, ahead of Romain Grosjean and Jolyon Palmer.

"A really good first day with the car and for me, so I'm very happy," beamed the German. "I have a great car that's as good to drive as it is to look at and already we've started to make some progress. This morning we completed just five laps while we worked with Mercedes HPP to make sure everything was as it should be. This afternoon we started to get into the programme and I added another 49 laps, so 54 laps in total. It's a really promising package so I can't wait to drive again in the morning. Thanks to the team for making me so welcome. Manor Racing is already feeling a lot like home."

"260kms with a brand new package is a dream start to pre-season testing," added Technical Director, John McQuilliam. "It couldn't have gone any better for us and every single team member deserves a round of applause for an impressive achievement. Pascal has slotted straight into the team and after a steady start to the day we really got into the swing of things in the afternoon session. He's had a confident debut and provided plenty of good feedback, giving us a lot of data to work with this evening. We'll pick things up with Pascal in the morning before switching over to Rio for his first taste of the MRT05. All in all, we've made a good first step."

Once conditions had improved, Haas hit the track with Romain Grosjean at the wheel. The Ferrari 061 turbo V-6 ran flawlessly, providing a valuable reconnaissance lap for the team to check all the car's systems. Twelve laps were made prior to the lunch break, and on the sixth lap, Grosjean recorded his fastest lap of the day (1:28.399). More laps would've been made, but a front wing failure cut the stint short. After careful analysis, a diagnosis was made and a new wing was reengineered for the afternoon. Quick work allowed Grosjean to make three five-lap runs, the last one coming with 24 minutes remaining in the session. When the clock struck 6 and the track went cold, Grosjean was credited with 31 laps, all on the medium.

"It was a pretty exciting day," said the Frenchman. "The morning went very well until we had a small front wing failure. It compromised our afternoon a little, but it was good that we could put some laps on the car later. We don't have any big problems. I'm very happy with the first day. It's been a really good start for the team. It's been a positive day. Of course, you always want more and more, but I think the most important thing is that I'm happy with the car. The first impression is really good. The car balance is there straight away."

"We had a good start to the day and then we had a problem with the front wing," added Team Principal, Guenther Steiner. "Obviously, we had to stop and evaluate the problem and find a solution. We found an interim solution, but we will have to find a solution by tomorrow morning. We got out running again and got a lot of data. It would have been nice to run more, but we still got some laps under our belt and we look forward to tomorrow."

"Today saw the first steps of the R.S.16, a car that has been delivered by everyone at Enstone and Viry to a very short and exacting timeframe," said Nick Chester, Chassis Technical Director at Renault. "We were circumspect with our programme today but it was a testament to all the hard work from everyone involved that we could take to the track at 9am. We did experience a number of growing pains today, mainly on the software side, and we're looking forward to getting some more laps on the board tomorrow."

"It was great to take to the track for the first time in the car I will race this season," added Jolyon Palmer, who finished the day eleventh, having completed only 37 laps. "We didn't have too exciting a programme to run through today and it was somewhat disjointed, but it was the first day of testing and we've completed valuable aspects of the pre-season build-up today. I'm looking forward to getting more running in the car tomorrow."

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