Whilst it would be foolhardy to attempt to read too much into testing, if the last four days have taught us anything it is that Mercedes remains the team to beat, that Ferrari has obvious pace, the force India and Red Bull have made progress and that McLaren-Honda is still hurting.

On a day when there were three red flags, Gutierrez and Magnussen stopping on track with technical issues and Haryanto spinning off and clouting a barrier, surely Fernando Alonso would have wished to be the cause of a fourth, his McLaren grinding to a halt after one hundred laps. Instead, the Spaniard was reduced to the role of spectator after just three laps as one problem on the MP4-31 led to another.

Having had his fair share of problems yesterday, today Kimi Raikkonen was able to stretch the legs of the SF16-H, even getting around to trying the new purple ultra-softs as he closed to within 0.6s of the best time posted by his teammate earlier in the week.

Daniil Kvyat also got to try the new compound, the Russian taking second spot and demonstrating that perhaps the coming months might not be as bad as some at Red Bull were predicting.

Force India continues to impress, as does young Alfonso Celis, the Mexican looking a lot stronger as his confidence builds.

After a few issues at the start of the week, Renault enjoyed another strong day, Kevin Magnussen completing a mileage tally that will have impressed Mercedes, and closing to within 1.7s of Raikkonen's pace to boot.

Likewise Toro Rosso, where Max Verstappen completed another 110 laps in a car which looks certain to be strong in what promises to be a very tight midfield.

Mercedes? What can one say about this team? Having admitted that it wasn't going to both switching to any of the soft compounds this week, and allowing itself the luxury of alternating its drivers at will, the Silver Arrows completed another 185 laps and even took time out to introduce a number of radical new parts... as if to remind the opposition that, like a shark, it never stops moving in pursuit of victims to devour.

"Workmanlike" is probably the word we should use regarding Williams this week, the team adopting its Grand Prix Friday modus operandi of quietly getting on with the job in hand without drawing attention. However, today was a bit of a let-down, a systems issue side-lining Felipe Massa for much of the afternoon.

Haas and Manor both had 'interesting' days on which they realised that there is still much work to be done, whilst McLaren, its driver and fans, will be hoping that today was merely a blip, and that the dark days of 2015 are not to be repeated.

"It was a normal test with different kind of tyres," explained Raikkonen, "but it is always different from what you see at the races. We have a new car here and there is always something to try, to test. So it is necessary to check everything.

"Testing time is painful," he admitted, "but it is better to do checks beforehand than having big problems during the Championship.

"I don't know if this is going to be a good car, no one can tell, but it seems to be a good car even if there are still many things to try out.

"We don't look at what the other teams do, we do our stuff and get ready. It's up to us to make sure we are in a good position. There is a good potential but we can still improve.

Kvyat brought Red Bull test to a close by posting 96 laps and claiming the second quickest lap (1:24.293).

"I had two quite good test days," he said, "even though we would like to do more laps. But we have two days left next week, so it will be important to extract the maximum out of that opportunity, to figure out where we can make steps forward.

"Obviously it's important to develop the car for the first race in Melbourne but even beyond that I think it will continue to improve as we understand the car more and more. We'll try to get as much done as possible next week, I'm looking forward to it."

"We had a very good end to our first week of testing," added Head of Race Engineering, Guillaume Rocquelin. "Overnight we found a solution to the niggle that affected us over the past two days and that enabled us to run pretty faultlessly today. It also meant that Dany was able to make up for the time lost yesterday.

"We focused on short runs, which is why the lap total is not that significant, as you obviously have to bring the car in more regularly and that delays things, but overall we're happy with the amount of work we got through today. In fact, I think we're satisfied with how the whole week went.

"Coming to the first test your main mission is to see whether you can run reliably, to find out if there are any issues and then to address those if you can. We've accomplished all those tasks this week and I think we're where we want to be. We have four more days of testing next week and they are going to be incredibly busy, so a small rest now and then full steam ahead again next week."

Alfonso Celis was back behind the wheel of the VJM09, the Mexican completing 75 laps with a best time of 1.24.840.

"It's been another busy day with lots of aero and procedural work," said the youngster. "Once again the car has shown great reliability and we managed to keep to the run plan without any significant issues.

"In the morning I was running mainly on the medium tyres and then moved to the softs in the afternoon.

"Each day in the car is a massive learning experience for me and I feel more comfortable with each run. I've also been able to get to know the engineers better this week, which is very important for the work I will do for the rest of the season."

"Another useful day of testing as we continue to prepare Alfonso for the work he will do for us during some free practice sessions," admitted Chief Race Engineer, Tom McCullough. "For example, we made sure we worked through many of the car procedures that he will be expected to do later in the year. We combined this with aero correlation to make sure we captured all the necessary data to feed back to the factory.

"He continued to take a mature approach to the tests, improving with each run as he built up his experience in the VJM09. Overall we can feel happy with how things have gone this week. It has been a productive four days and we've made good progress with understanding the new car, which leaves us well placed to maximise the final four days of testing next week."

Kevin Magnussen concluded the final day for Renault completing a bumper 153 laps as he worked on aero logging, set-up work and a full race simulation including pit stops.

"I certainly have had a workout over the last couple of days with over 260 laps completed!" smiled the Dane. "It feels so good to be back in an F1 car and working through the programme and making strong progress.

"Our race simulation went well and I'm really gelling with the team; it's a real pleasure to be driving here and I can't wait to get back in the car on Tuesday."

"This has been a productive first test for us," said Racing Director, Fred Vasseur. "The initial R.S.16 planning meetings took place at the end of September last year so it's clear that everyone at Enstone and Viry-Chatillon has made a tremendous effort to produce it and facilitate the performance we've seen today and this week.

"Jolyon and Kevin have demonstrated themselves to be an accomplished and hungry pair of drivers," he added. "With the mileage accumulated over the last two days we have a good baseline. We have a lot of work yet to do, but it's a solid start to the season."

"We can be pretty proud of the mileage we've achieved during this first test," insisted Toro Rosso Technical director, James Key, "because we didn't know really what to expect, coming here with so many unknowns with the new power unit and a complete new car in the STR11. But I think the whole team has pulled together extremely well and made it possible to do four days of generally pretty productive testing.

"I think most of the things we wanted to achieve here we've done," he continued. "Most importantly, we wanted to prove that the car worked as hoped with the new power unit installation and all the new complicated mechanical systems, and that appears to be the case, so we are very happy with that.

"The drivers have done a very good job. Carlos did 161 laps in one day, which is a huge amount of mileage, and I think he dealt with it extremely well. Max did 110 today, so in general we've had plenty of opportunity to prove reliability, which is critical with only two test sessions before the season starts.

"Working with Ferrari has been extremely easy and straightforward, they've supported us very well. We've had some good cooperation with them over the past four days and I'd like to thank them in getting things prepared on time.

"We've ticked a lot of boxes for general car operation reliability, but we've only just started to learn what makes the car tick, so now we need to work much more on the performance side of the car, extract more out of that and bring some new updated parts next week. We're looking forward to that."

"Today was another good day," added Verstappen, "we managed to do a lot of laps, especially in the morning. We are understanding the car more and more and I think it all worked out well. The car is behaving well, so we can be happy. This first test has definitely given me confidence in the car. It was important to run as much as possible and we've certainly achieved this goal! I look forward to next week's test where we will continue to work as hard as this week."

Felipe Nasr completed another 121 laps in the Sauber, the 2015 car's last outing before the 2016 C35 makes its debut on Tuesday.

"It was again a very intensive day," said the Brazilian. "I collected a lot of mileage while driving the C34 for the last time. In the morning our programme was dedicated to tyre evaluation. I did many short runs on soft tyres. After the lunch break we mainly focused on set-up work and at the end of the session I was able to do a long run. Now I am very much looking forward to driving the new C35 next week."