Kimi Antonelli finally gets a trouble-free session and responds with the fastest time of the week, as Aston Martin's struggle continues.

On the face of it, today's final day of testing was pretty nondescript. With Pirelli holding back the fastest compounds there was no point of 'glory runs', while there were only two red flags, neither due to anything serious.

However, though the pecking order remains far from clear - especially if you listen to some of those involved - we did get some of our questions answered, particularly in terms of reliability.

The 17 drivers completed 1,418 laps - the most this week - with Oscar Piastri completing 161 laps in the McLaren, Hamilton 150 laps in the Ferrari, Colapinto 144 in the Alpine, 146 for the Williams pair and 145 for Haas.

When he didn't emerge until ninety minutes into the afternoon session - teammate George Russell having completed 78 laps this morning - it looked as though the test curse had hit Antonelli once again, however once on track he soon racked up the lap count and having gone quickest set about chipping away and improving.

A number of drivers completed race sims, most notably Hamilton and Piastri, who started theirs around seven laps apart. Both will surely leave here feeling confident, however with Mercedes posting the best two times of the day it will give them food for thought.

At the other end of the timesheets, Cadillac is getting on with the job, likewise Audi, with Hulkenberg looking more comfortable in the car than his young teammate.

Despite - or perhaps in spite of - the claims from Mercedes, its customers and its customer's drivers that Red Bull is the benchmark, Max Verstappen and Isack Hadjar only completed 114 laps between them and both were over 1.5s off the Silver Arrows pace.

As on previous days, there were lock-ups and offs as drivers continue to get used to the new cars, which have been described as constantly driving with Monza levels of downforce.

The two red flags were down to Valtteri Bottas who is thought to have suffered a cooling issue this morning, while Hamilton is understood to have run out of fuel at the very end of the session.

At one point late in the day, Hadjar pulled up at the McLaren pit by mistake and had to be waved through, while at the end of the session as drivers headed to the grid for a practice start, Colapinto almost put his into the barriers as he carried out a burn-out. In his eagerness the Argentine got two wheels on the grass and was lucky to keep it out of the barriers. No doubt Flavio was already in the process of recalling Jack Doohan.

A couple of drivers, including Piastri, failed to get away at the practice start, while Colapinto's car went into anti-stall and he stopped at Turn 1.

We had hoped to have some idea of a pecking order by now, but while there is a very rough semblance, despite what we are being told there is no clear benchmark.

And while, as Verstappen claims, there might be an element of sandbagging going on, one team clearly does have issues.

Yesterday, Lance Stroll claimed that the Aston Martin is 4s - 4.5s off the pace, and today his best lap was indeed 4.49s off Antonelli best.

In all honesty the car doesn't look good, that's when its actually on track.

Some are pointing to Honda, arguing that the Japanese manufacturer is lacking data as it is only supplying one team. Others point to the gearbox.

"It's one of these issues," admits Fernando Alonso. "But we mustn't forget that for the first time in the team's history, we're producing the gearbox ourselves. It's a challenge; we need more information."

"We are clearly behind," said Aston Martin ambassador, Pedro de la Rosa. "And when you are losing or you are missing that amount of time, it's clearly the overall package.

"We cannot say it's this or the other," he added. "There's a lot of areas where we have already identified clearly and we are already working in Silverstone to address them. It won't be an overnight fix. It's not a five-minute job."

It's somewhat ironic - hopefully not prophetic - that the Silverstone-based outfit recently appointed Jenson Button as a brand ambassador, for this is beginning to have a 2015 feeling about it, when the Briton - and Alonso - were suffering the birth pangs of the McLaren-Honda.

Trouble is, one gets the feeling that yet again Alonso is going to leave/retire just as everything comes good. No doubt Max is watching proceedings with great interest.

At Mercedes, Russell and Antonelli split driving duties, with both focused initially on single lap work before switching their attention to race simulations to end their weeks. The Briton topped the times in the morning session before his teammate surpassed this in the cooler conditions of the afternoon.

After two challenging days to the start the test, with several reliability issues affecting the team's programme, Friday was more effective with Russell completing 78 laps and Antonelli 64.

"We've enjoyed a much more productive day in Bahrain than the previous two have been," said Russell. "That was important given how much running we had missed on days one and two. We were able to work through some single lap and high fuel running, completing a race distance to end our morning.

"We've struggled with reliability this week and our performance hasn't been where we want it to be. Today, the car felt better balanced than previous days and our pace was reasonable. That said, it is clear that our competitors have looked much stronger than they did in Barcelona and that we have work to do to catch them up. We will put in the hours ahead of next week's second and final pre-season test to improve and hopefully we can get closer to our rivals ahead of the first race in Melbourne."

"It's been a difficult test for us as a team, particularly on my side," added Antonelli. "We have encountered several reliability issues that meant I only managed just over 30 laps across the first two days. It was therefore a good afternoon today where it was really my first time properly getting to grips with the car here in Bahrain. We were able to complete a good amount of single lap work and then came close to finishing a race simulation.

"Whilst this week has been frustrating, it is much better to have these issues now and be able to work through them, rather than them happening during race weekends. The team is already working through solutions to some of our problems and we can hopefully come back stronger next week. Several of our rivals have looked particularly good and have enjoyed much more trouble-free running here than us. We need to try and extract more from our package and hopefully can begin to make up some of our gap during the second and final pre-season test."

"We had our strongest day of this first test today," said Andrew Shovlin, "but still spent far longer in the garage than we would have liked. We have not achieved what we wanted to during this first test and a good amount of work has now shifted into next week's second and final test. That is frustrating but all part of testing; it's important to face these challenges head on before the season proper starts.

"Pace wise, we made solid progress today but the W17 has been harder to keep in a happy window here compared to Barcelona. We have a decent baseline to take into next week but it's clear that some of our competitors, who have had a smoother first test, are in a better position than us and that we have work to do to catch up. Hopefully we can begin to do that during the second test next week."

Hamilton took to the track shortly after 10, and for all the first part of the day, the car was fitted with C3 compound tyres. The programme centred on a continuation of set-up work and on acquiring data, as had been the case in previous days. Particular attention was paid to comparing different car configurations, as well as assessing tyre behaviour. The Briton did 69 laps, with a variety of run lengths. His best time in the morning was a 1:34.209.

After the lunchbreak, he continued running the C3 tyres, gathering more data and learning more about the car. In the second part of the afternoon, the two other compounds came into play, first the C1 and finally the C2, thus completing a comparison of all three available compounds. In the afternoon, Hamilton did 80 laps, having had another busy and useful day in terms of SF-26 development.

"It's been a positive week overall," said Hamilton. "We completed a lot of laps and went through the full programme, which allowed us to gather plenty of useful data and learn more about the car.

"The SF-26 has felt generally good, but this generation of car is quite complex and finding the right operating window, especially with the tyres, is key. We've made some good discoveries and also identified areas where we can improve. We still have another test ahead of us, which will be important to build on what we've learned and continue making progress."

"Going into the season, the target was to make the most of the first test sessions by accumulating mileage and collecting as much data as possible," added Fred Vasseur. "So far, everything has gone well from an operational point of view, with good reliability and plenty of laps completed, which is important both for our preparation and to analyse the data back in the factory.

"We will use this information to continue improving the car and our understanding of all procedures. Performance is a separate matter: the priority at this stage is to build knowledge and put ourselves in the best possible position ahead of Melbourne, knowing that we still have time to make further steps forward."

McLaren concluded the test with 161 laps completed by Piastri, the second consecutive day a McLaren driver has covered the most distance. This results in a total distance of 2,283.864kms from 422 total laps completed by Lando and Oscar across three days of productive running.

The Australian started Friday morning's session on a similar programme to the one completed by his teammate during yesterday's running. This involved further aerodynamic testing for the team, focusing on a number of runs with aero rakes attached to collect valuable data. This will provide further understanding and development across all areas of the MCL40 before moving on to longer runs.

The afternoon session saw the team move onto additional race simulation with lots of laps completed, providing important practice for Oscar as he performed multiple overtaking manoeuvres, giving the Australian driver key insight into race preparation and what managing the car in traffic could look like this season.

Overall, the first week has given the team the opportunity to gather key learnings across all areas including car setup, exploiting power unit performance, and overall reliability.

The team recognises that there will be lots of opportunities for further learning throughout next week's test 2. However, before the MCL40 returns to track action on Wednesday, all data from the last three days will be reviewed and analysed collectively with the entire team, both trackside and in Woking.

"A productive first week of testing," said Piastri. "The car ran well and we've learned a lot about what it likes and what it doesn't like. It's going to take a while to get used to driving these cars and how to get the most out of them, so there's still a lot to learn. I am looking forward to getting back out there next week and keeping this learning going. A big thanks to the team for their work which has meant we've been able to get a lot of laps on the board and maximise our programme."

"Today concludes a constructive and productive first phase of Pre-Season Testing with a total of 2,283.864km completed by Lando and Oscar across the last three days," added Andrea Stella. "This is very encouraging to see with lots of key learnings to take away. With that said, and while it is still difficult to accurately identify the order of performance, it is clear that Mercedes and Ferrari are currently more competitive than us. We have some work to do to find performance ahead of the second test next week and the first race in Melbourne.

"From a testing perspective, both drivers have provided valuable data from every individual lap in each of their sessions. The aerodynamic testing undertaken both yesterday and today provides the team with particularly valuable information that will play an important part on the next steps of our development for the MCL40. It was also useful for Lando and Oscar to complete race simulations as part of their programme, including some running with other cars. There are some areas we need to work on, both as a team and as a sport, but we leave the first test with a better understanding of these requirements.

"Finally, thanks go to the team for their hard work and dedication to get us to this point. There is still a significant amount of work to do, but each lap we complete gives us additional learning, and that isn't possible without the hard work of the team both here in Bahrain and back in Woking. We look forward to heading back out on track next week."

"Looking at the test overall, the team got in a good number of laps on the first day so we were happy with that," said Max Verstappen. "We completed a lot of things that we wanted to test with the new power unit and the car in general.

"Today it was a continuation of that plus also trying to explore a little bit more with the car," he added, "you go through so many test items that it continues to change and evolve with everything that you are testing. In general, it is all so new that we are still learning a lot, but the car was good. We also have new tyres, so we spent some time looking at different sets and understanding what we need to improve and be better at.

"With the power unit, looking at the laps we got on the board, the start that we have had is good. That's exactly what we wanted to do and it was not a given. Whether it will be enough to win races, we don't know, we will just focus on ourselves and try to do the best we can, but there is still massive room for improvement.

"Finally, with the car, we learnt a lot about what worked and what didn't. Our runs also gave us even more ideas for the afternoon with Isack and then for next week, where we can continue to try new things and different set ups."

"The first week here in Bahrain has gone well," said Hadjar. "Of course, I had to wait a little before getting in the car after Barcelona, but once I did, we were able to put it to the test and really work through what we need ahead of next week and Melbourne.

"There are so many things to look at, but we're staying on track with our programme so far. True performance and pace are always hard to judge in pre-season, but we can be happy with the reliability we've had from the power unit this week. There are still things to work on in terms of balance and tyre management, but that's completely normal for this time of year. We're working through it together as a team to get where we want to be for Australia. I've known the people here for a while now, but it's great to be working with them again in an environment like this."

"It has been a positive week," said technical director, Pierre Wache, "running a full day with Max, with plenty of testing time as we worked on understanding the car and the direction to go in with the power unit.

"Unfortunately, on day two we had some problems with the hydraulics on the chassis side, which compromised Isack's running in the morning but we were able to recover this in the afternoon.

"This morning with Max we evaluated set-ups and saw some good direction and this was similar with Isack this afternoon, so it's been quite positive with the mileage done this week. We need to make sure the car continues to develop a lot more to improve the issue on the balance side and we know that there is a lot of room for improvement. Our drivers are very motivated and have given us a lot of feedback on where we can improve the car and how we can change the direction of development.

"In general, Red Bull Ford Powertrains has done a remarkable job as a start-up; in three and a half years we have created a power unit and have it out running on track, which is fantastic. The second step is to see where we are sitting compared to others and improve. There were a few teams which were clearly very quick today and it looks like we are behind, so there is still a lot to improve. Mercedes, McLaren and Ferrari are there at the top. It is a massive learning curve, there are plenty of unknowns and a lot to do. We have been evaluating our weaknesses and strengths and are just focusing on improving the car. We go into next week looking at what we can bring to the car to make it better and solve the issues we have identified."

"It was good to end the week with so many laps on the board," said Colapinto who completed 144, the third most of the day, "and it is positive to go into the weekend now with a lot to look at and understand.

"The car ran well today, we really targeted doing a lot of laps to continue building up my experience in the car. Pierre had a good day yesterday and the car felt in a decent place straight away this morning, which allowed me to build everything up run by run, lap by lap. We did a real mix of running and tests and began to have a feel and more detail into how the car behaves. I think we have ended the week in a good place.

"We completed 318 laps in total as a team, and there is a lot more to do next week when testing resumes. Lots to learn and I leave this test in a much better place than when we started so a big thanks to the entire team for their amazing work this week."

"We knew it was going to be a challenging three days getting up to speed and starting to understand the new car and regulations," said Albon. "The positive is that we got quite a few laps under our belt and the car seems reliable, which is never easy for the first week of testing.

"On my side, getting to grips with a new car has been a challenge," he admitted, "but I am enjoying the intricacies of it. There's a lot of improvement to be done and a lot to learn to bring a better package for the next round of testing, so it will be a busy next week of really digging in to the data."

"Overall, it's been good to test the car properly these past days and be able to do as many laps as we have done," added Sainz. "We are still playing catch up on certain things, but doing over 210 laps has given me a much better understanding of what we can expect this year.

"The cars feel very different and it's going to be a challenging season, but this is nothing new and I'm up for the challenge.

"It's still early days to discuss performance in detail and compare ourselves to our direct competitors, but it is clear that the gap between teams is not as tight as last year, at least not for now. What is important for me is that we have identified the main areas we want to focus on in the upcoming weeks and I hope that we can improve gradually as we get closer to Melbourne. There is a lot of work ahead of us as a team so there is no time to lose."

"We've had a productive week," said Racing Bulls Alan Permane, "spending it learning as much as we can about the chassis, the power unit, the performance and how they all integrate. Like everyone in the paddock at this stage, we've encountered a few teething issues, adjusting settings and uncovering the unexpected, but that's all part of the process and without reliability, there's no foundation for performance. We're on a steep learning curve and every time the car leaves the garage, we make improvements. I'd say from where we were at the start of Barcelona, to where we are today, is night and day.

"The power unit has been mightily impressive," he added. "We've concentrated on mileage over performance, running high-fuel programmes and making chassis adjustments where we can. We had a couple of reliability issues, which cost us some track time. However, we made significant improvements in the operation and the integration across the power unit, the chassis particularly with gear shifts and starts, where all these functions have vastly improved.

"The next stage will all be fine tuning and that process will continue through the season. The important thing is that we're building a strong baseline and putting solutions in place ahead of Melbourne. We'll continue pushing reliability in next week's test, while starting to shift a little more focus towards performance."

"After completing the shakedown in Barcelona, we have now finished our first test of the new season," said Mike Krack. "We ran into some issues earlier in the week, and that's exactly why we go testing - especially with new regulations.

"This whole package is very fresh," he continued, "so it takes time to understand all the different elements and identify where we need to improve.

"A big thank you to the entire team for the hours worked across the three days of testing. We are realistic in knowing that there is a lot of performance still to unlock in this package, and it is important that we analyse all of our learnings ahead of next week."

"It's clear after the first week of the test that we are behind schedule and not where we want to be," added Pedro de la Rosa. "We had limited running in Barcelona and we ran into some issues on day one of the test this week in Bahrain.

"Fernando and Lance have logged some decent mileage over the last few days, but we are catching up and always learning about the new package. We have the talent and resources to improve the car, and the team and our partners are all working incredibly hard to make this happen, both at track and back at Silverstone."

More to follow.