On paper it will appear that it's business as usual as a Mercedes driver tops the timesheets at close of play. However, other than the fact that the gap to runner-up, Pierre Gasly was only 0.124s, the fact is that the Finn's best lap was set on the softest tyre in Pirelli's range, and even then the performance was hardly convincing.
As ever the world champions have yet to show their hand, but the fact is that, all things considered, Mercedes appears to be making heavy going of testing and really hasn't appeared to grab the (Red) bull by the horns.
True, other that Hamilton's off this morning and a moment of overenthusiasm from Bottas this afternoon, it's been a trouble-free day for the world champions who completed 116 laps in total. But like a seagull - assuming you've seen one take flight - the world champions appear to be taking forever to get off the ground.
"It was a lot better for me than yesterday, for sure," said the Finn. "I finally managed to get some laps and some clean runs to really learn about the new car and try some things.
"It's always good when you learn and that's what testing is all about," he added, "the opportunity to run different things and see how the car reacts. As a driver you use that information in a race weekend so it's hugely important. If the set-up changes work or don't work, it's all valuable information.
"For sure it's windier here than we've had at a race but one of the bigger issues with the car is the rear end, it's quite snappy and unforgiving. With the new tyres, it's quite sensitive so we need to calm the car down a bit."
On topping the timesheetys, he said: "It's so difficult to say what that means. I can't be jumping around happy - it is only testing. As always, we are just focused on getting through our programme and maximising the learning. You never know what fuel loads people are running. Hopefully by the end of tomorrow, we will have a better idea of where we are.
"Testing is limited and a lot more compromised this year for everyone, you have less time in the car before the first race so I would be happy if we could just get through the final day tomorrow nice and clean. Today felt good and the times were pretty fast, so I just want more laps and more feeling with car."
"It was OK, better than yesterday - not so much sand," added Hamilton. "The track doesn't have a huge amount of grip and long runs aren't the easiest but at least the sun was out! The balance was slightly improved compared to yesterday but we're still working through certain things.
"For today the wind did a 180 degree shift so the track was very different, and you could push in certain places where you couldn't yesterday. It was very gusty as I found out at turn 13 and the rear doesn't feel particularly great with this new regulation change but we're still trying to find the sweet spot.
"I've done 60-odd laps today and Valtteri missed a lot of track time yesterday so it's not a lot compared to other tests we've had but we're trying to be as effective as we can. We have less mileage than some of the others like Red Bull but we're just trying to stick to our programme and manage the laps to try to be efficient. We're just focusing on understanding the car, there's no point in getting worried."
"It was a better day than yesterday and we were able to run to plan in both sessions," said Andrew Shovlin. "Lewis was in for the morning working on setup items and data collection and Valtteri continued with similar work in the early part of the afternoon. We then spent the latter part of the day doing qualifying simulations with Valtteri on the softer compounds.
"We've made progress on the setup today and the balance was more together by the end of the session, albeit in calmer and cooler conditions. But the car is still a bit of a handful in the warmer and windier conditions of the morning and that's something we need to get to grips with tomorrow. It's going to be a busy day; we've got more than enough to do so we're hoping for a trouble-free day."
After yesterday's sandstorm, today's much improved conditions allowed the teams to ramp it up a notch and this afternoon we finally saw some pace, courtesy of the red-banded rubber, while race sims also became the order of the day.
Impressive yesterday, AlphaTauri continues to shine, with Pierre Gasly finishing second to Bottas and only 0.124s behind. With Yuki Tsunoda in action this morning, between them the Faenza pair completed an impressive 144 laps, the AT02 looking like it will be up for the midfield battle that lies ahead.
At one point we saw Gasly following Latifi, the Frenchman seemingly unable to nail the Williams. However, it soon became clear that he was merely trying to understand how the AT02 reacts in dirty air. Indeed, once the 'experiment' was completed he left the Canadian for dead.
"It's been another really positive day for me," said Gasly, "with a lot of laps done this afternoon. We managed to complete all the high-fuel running that we wanted to at the start of the session and then some performance runs towards the end, with the softer compound. I feel really good in the car, especially compared to this time last year, so it's really positive for me.
"There are obviously places we still need to improve upon, but I think we're in a good place with one day left of running at this test. The Honda Power Unit is working really well so far and we haven't had any reliability issues which is great - I'm excited to get it out on track for the race. With only three days of testing - split between two drivers - I knew it would be difficult but considering how many laps we've been able to complete so far I'm feeling quite comfortable with the car ahead of the Bahrain Grand Prix."
"I think for me on the driving side things are definitely improving each time I go out," added Tsunoda. "The weather again today has been an issue, particularly with the changes in wind direction, so it's definitely been a big learning curve.
"I'm really starting to understand the car and how it reacts with different tyre compounds now," he added, "my performance isn't perfect yet but I'm happy with how the test is going from my side. I'm also getting more confident in high speed corners, as I continue to understand the downforce levels of the car more with each run we do. It's good learning for the team, and also for myself, so hopefully we can put it all together tomorrow."
"Overall, we had a very productive day and were able to recover the lost kilometres from yesterday afternoon," said Jonathan Eddolls, the Faenza outfit's chief race engineer. "Yuki was on duty in the morning session, which started with a very dusty track from the high overnight winds, but this didn't impact the aero running we did with him during the first couple of hours.
"We then got into a block of mechanical setup items before closing the morning with his first experience of the new soft compound. He performed well and is in a good position for his last half day of testing tomorrow, before the first race.
"We swapped to Pierre for the afternoon and had a mixed plan of long runs and performance runs, again trying to learn about the 2021 tyres and how best to optimise the car for them. We found some interesting directions to analyse tonight and then we can explore these tomorrow. I'm happy with the progress we've made today, as we've been able to complete our plan and cover 144 laps across the two drivers.
"We still have some work to do tomorrow but we're on plan to complete all our testing items and be in a good shape ahead of the start of the season."
"Overall a very positive afternoon after a difficult morning for Sebastian where some technical issues limited our running," said the Canadian. "Track conditions were not so easy - it was still quite windy, but even in those conditions it felt great to be back driving and getting lots of laps under my belt.
"The afternoon programme went to plan: we completed the main jobs and ticked off the test items. There's still lots to catch up on tomorrow, but I'm feeling pretty pleased with a solid afternoon."
"It was not such a busy day for me," added Vettel. "We experienced a gearbox issue quite early on and that kept the car in the garage. The guys did a great job to quickly fit a new gearbox and we got back out just before the end of the morning session.
"Doing so few laps today wasn't ideal," he admitted, "because there is just one more day of testing before we come back here for the race and I am still learning about this new car. Fortunately, things went a bit better this afternoon for Lance giving us some important information. Hopefully, we can have a more straightforward day tomorrow."
This morning Daniel Ricciardo set the pace, having done so yesterday, while this afternoon Lando Norris was just 0.297s off the pace despite using slightly harder rubber than the three drivers who went quicker.
"Another positive day," beamed Ricciardo, "it's been a good test so far and I'm looking forward to the evening session I'll be running in tomorrow.
"We've been able to get a lot of laps in and tick off every run we had planned, which is important for us in terms of reliability and starting to build my confidence in the car.
"All I'm missing now is that evening session, I've had two of the morning sessions when the track is hot and usually we come here at night. But tomorrow, I'm on track later on and I think I'll be able to push the car a bit more and get a better feeling of how comfortable I am, as well as a better understanding of how ready we are for two weeks' time."
"A good second day in the car," added Norris, "a bit cleaner and more straightforward today in terms of the weather conditions, which meant we could do more normal running.
"We did a mixture of aero runs for half of my session, and some shorter and longer runs to look towards weekend preparation. It's good to get an understanding of both types of running to assess areas we need to work on ahead of race weekends, but also for tomorrow on track.
"We'll go through everything tonight, come back tomorrow with some improvements and make sure we're as prepared as possible before leaving Bahrain after three days and heading into the first race."
"A useful day of testing," said James Key, the Woking team's technical boss, "it's good to get both drivers back in the car again after they've had some time to process and analyse what they experienced on day one. We had quite a varied programme today which we got through as we'd hoped, covering over 100 laps between our two drivers, who worked on a number of aero tests and measurements, looked at some different tyre compounds in a bit more detail than yesterday, as well as completed both one-lap configurations and longer running which will give a bit of a heads-up of what to expect in those conditions. Our set-up tests were useful in confirming some of the learning and direction we gained from day one when we had more difficult track conditions than today. We also were able to conduct some tests to sign off aspects of our new power unit installation and operation with our colleagues at Mercedes HPP, which were completed as planned.
Check out our Day 2 pre-season test gallery from Bahrain, here.
"Overall, it's been a positive and busy day with a good level of reliability. We only have one day left of testing now before we hit the track for the first race of the season, so we'll hope for a similarly productive day tomorrow and aim to maximise the small amount of time we've got left."
Giovinazzi and the team devoted the best part of the morning to long runs, the Italian quickly settling into a rhythm and grinding lap after lap with impressive consistency. In the afternoon, the focus shifted to shorter stints, with performance runs showing a glimpse of the car's qualifying potential.
"I am really happy with the work we did," said Giovinazzi, "it was a long day, with a lot of laps, but I think we ticked all the boxes on our list. We did long runs and qualifying runs and we managed to achieve all we set out to do.
"It was my last day in the car before the first race and I feel confident about the season. We worked very hard during the winter and we are ready for the first round: it's hard to say where we expect to stand, I think we have a good baseline but we won't know for certain until the first qualifying of the year."
"It was another good day of testing, with 125 laps to our name," added technical director, Jan Monchaux. "We were able to run our first race simulation in the morning: it went well and we learnt a lot of things that will serve us well during the season. The focus in the afternoon was more on our one-lap performance and on set-up work.
"It was important to have another full day without reliability issues, so that we could run all the tests we wanted. Antonio did a great job, extracting most out of each lap, as he did yesterday. Now the baton passes to the engineers, crunching the data and preparing tomorrow's session.
"Kimi will be back in the car and we're very likely to run a similar programme to today's to close off our testing week."
The day saw Leclerc and Sainz working on slightly different programmes. As planned, the Spaniard was the first to drive, going out at 10:00 to tackle a programme aimed at evaluating the Pirelli tyres over a long distance. He did a series of long runs, using both the C2 and C3 compounds posting a best time of 1:33.072.
After the lunch break it was Leclerc's turn to get to work and he too did some long runs on the C2 and C3 tyres. In the final part of the session, the Monegasque did a series of runs aimed partly at a qualifying simulation with various tyre compounds. By the end, his best time of 1:30.886 was set on the C5 compound.
"Another very busy day of testing," said Laurent Mekies, "with almost 700 kilometres covered during the eight hours of track time. The weather was much better than yesterday, although the wind was still a feature, especially in the first part of the day.
"We worked a lot on management of the Pirelli tyres over long runs and we got plenty of data which we will now analyse carefully. In the final hour, we also began to look at how the SF21 went in terms of outright performance and here too, we gathered a lot of useful information.
"These three days are vitally important and we are taking a methodical approach, because the work we do now will be the key to how we get on during the season. Therefore the most important thing is to complete the planned programme and that's what we have done so far. As for the competition, we can start thinking about that in two weeks time, in qualifying for the Bahrain Grand Prix."
If Roy Nissany impressed yesterday - and to be honest he did - how about Nicholas Latifi and Williams today. The Canadian completed the most laps (132) and at one stage was trading fastest sector times with the midfield runners.
Having been shadowed by Gasly earlier in the afternoon, Latifi was subsequently hounded by another Honda-powered driver, Sergio Perez. In this instance however, as the Mexican pulled out from behind the Williams on the main straight, his engine cover exploded as air got underneath, littering the track with debris and causing a red flag.
With Latifi having made a few minor mistakes today, it is going to be interesting to see how George Russell performs tomorrow when we should get a better picture of where Williams stands in the pecking order.
"We had a busy day, completing 132 laps without any major issues," said Dave Robson, the team's head of vehicle performance. "The track changed throughout the day making comparisons difficult, but we were still able to complete some useful work. It was good for Nicholas to get a trouble-free day and to experience the car in a range of conditions and on a range of tyres.
"It looks like the weather will be a bit different again tomorrow when George will be in the car to complete our pre-season testing. We still have a lot to do, but we are confident that we can have another productive today tomorrow and get ourselves into the best possible position for the first race."
"It was great to get some proper running back behind the wheel," added Latifi. "It was nice to push the car in the dry and knock the dust off from the winter. It was a tricky day with the wind, but it was good to get some running in these conditions as there was lots to learn.
"As is normal in pre-season testing, there were a few half-spins as I was pushing to see what the limits were. I think we can be happy with the number of laps we completed today, and we now have a lot of data to analyse to be as prepared as possible for the first race of the season."
Other than his exploding engine cover the Mexican kept a low profile, completing 117 laps over the course of the day.
"It was great to do a full day of testing in the RB16B," said Perez, "and even though conditions are very tricky out there we got through plenty of work and there is plenty of development to come.
"It's great to be working with the team and I'm getting more and more used to things - I can already feel the potential. I have the morning tomorrow in the car, so I'm looking forward to getting in some more laps."
"Sergio got through a full race simulation today," added head of race engineering, Guillaume Rocquelin, "including pit stops, which was very useful for him as he embeds with the Team even more and gets up to speed with all our procedures.
"We had a couple of small issues - nothing huge and it didn't affect our engineering programme, so in a way these are things you want to find out about in testing. Those niggles aside, it was another solid day.
"It is clear that we have not been chasing lap times and have only run one of the harder compounds, so there are no real conclusions to be drawn from the overall time sheet. All in all, two good days and hopefully we'll close out the test with another productive day tomorrow."
The Austrian team opted not to try the softs, preferring to keep its power dry. However, there is no mistaking the quiet air of confidence that surrounds the team.
Check out our Day 2 pre-season test gallery from Bahrain, here.
Back in F1 following a two-year hiatus, Fernando Alonso opted to maintain a low profile today, quietly getting on with the job. Sticking with the harder tyres in the Pirelli range, the Spaniard completed 128 laps - the second most today - on his way to posting the tenth best time of the day, albeit 0.5s off Perez' best on the same rubber.
Alonso began his programme with an aero rake, driving his first laps with the team since the post-Abu Dhabi test in December. The rest of the morning saw the Spaniard acclimatise to the challenging conditions, with a mix of runs using the C2 and C3 tyre compounds.
Track and weather conditions improved for the afternoon session, with Alonso embarking on some longer runs fitted with the C2 and C3 tyres. The two-time world champion continued his run plan through to the evening and surpassed a century of laps with just over an hour left of the session.
Esteban Ocon will resume duties in the A521 tomorrow morning, before handing back to Alonso for the final part of the pre-season test.
"We completed a lot of laps today," said the Spaniard, "and followed the programme that was planned so that is good, but we need to sit down now and analyse everything.
"The car did feel good today, but I think we still need to understand the characteristics of the new aero package a bit better. We ran with the harder compounds today and we have more running to do tomorrow, so between myself and Esteban we will aim to collect even more data and fine tune the overall package."
Between them the Haas pair completed 164 laps, but even on the C4s neither was able to get within less than 2s of the main pace-setters.
The day was not without its incidents for the pair either, with Schumacher caught out by a 'slow off the mark' front jack-man and Mazepin involved in minor moments with both Hamilton and Giovinazzi, in both case the Russian compromised by his rivals traveling slowly on the racing line.
With a focus on banking additional mileage to complement the 70 laps recorded on Friday, Mazepin ended a productive morning behind the wheel of the VF-21 with 76 laps, which included a race simulation, and a fastest time of 1:33.101 - placing him 14th overall of the 16 drivers participating. The run plan saw Mazepin cycle through the C2, C3 and C4 tyres over the course of his session.
Schumacher strapped back into the VF-21 for the afternoon session, the reigning FIA Formula 2 Champion looking to make up for a frustrating Friday morning after a technical issue limited him to just 15 laps on day one of testing.
The German started his test plan with a series of short runs utilizing new C3 tyres before sampling fresh sets of the C4s. He posted his quickest time of the day on the C4, his 1:32.883 putting him 12th on the timesheets. Like his teammate before him, Schumacher then transitioned to a race simulation.
"It was much nicer out on track than yesterday," said Mazepin. "It was good this morning because we were able to get into more normal driving for here in Bahrain.
"Conditions had obviously really changed from last night, it was much nicer to drive, the conditions were much more representative of what it's usually like in Bahrain - it's all good track knowledge to collect.
"We're chipping away at it, which is good, and I'm getting to know every member of the team better and better. I'm aware that they're a very capable and very strong team. They need to get to know me too and see that I'm capable of achieving decent lap times and provide good feedback. We're all getting to know each other, but at the moment consistent running is the key to the test."
"It was amazing today," added Schumacher, "I really consider this as my first day in a way as yesterday was such a shame. Being able today to do things like consecutive running, going through C2, C3 and C4 tyres, it's been amazing. After two or three laps I really did feel comfortable in the car, which is promising, and it was a feeling that just increased over the day. By the end of the day I felt super comfortable - I felt at home.
"I feel like I've integrated with the team quickly, all the guys are really cool. I love working with them. I'm really looking forward to the season, it's going to be great. But for tomorrow, I'm just after more laps, that's our aim."
"It was a pretty good day for us today," said Guenther Steiner, "we did all our program and over 160 laps on track between the two drivers. We went through everything as planned, simulating almost all elements of a race weekend.
"Unfortunately, we couldn't take part in the sim qualifying when it was getting fast, but the most important thing was that both guys got a lot of laps in so they can learn all the procedures. We continue to try to get them as ready as possible for the grand prix in what is a very short pre-season test. I'm very happy."
As ever, though we can only read so much into the times thanks to the tyre compounds we don't know the fuel loads, and even then the times can vary depending on how old the tyres were.
However, all in all, Red Bull, McLaren and AlphaTauri continue to look good, Alfa Romeo and Williams could spring a surprise, Ferrari and Haas look set to disappoint, while Mercedes, Aston Martin and Alpine have yet to show their hands.
Check out our Day 2 pre-season test gallery from Bahrain, here.