The teams reflect as the fourth day of pre-season testing comes to an end.

Mercedes

Lewis was behind the wheel in the morning session and focused on set-up work on longer runs, alongside gathering aero data and trying out new aero components. Valtteri took over for the afternoon and ran a similar programme of car set-up, aero data collection and correlation work.

Today's programme focused primarily on testing, correlating and gathering data on new aerodynamic components, as well as longer runs and set-up work.

Lewis Hamilton: It's been a good session and a good start to the second week of testing here in Barcelona. We've just got our heads down, trying to continue increasing our mileage and our understanding of this car - through the subtle changes with car set-up, the tyres and the aerodynamic package. A fairly standard day, but it was a bit windier out there and it felt like the track had less grip - so there was some sliding around. The car didn't quite feel as good as the first week, but I'm sure that will change as the test progresses and the track conditions improve.

Valtteri Bottas: Very good mileage today, 90 laps. For half a day in the car, that's really good. We got some good set-up tests done and focused on long running. I think we picked up lots of learning points, although it was a bit tricky this afternoon with gusty wind, which made it sometimes more difficult to understand the set-up changes in detail. But I am sure we'll analyse everything overnight and find the learnings from it. Everything ran smoothly, except a slightly late start to the day with some big changes over lunchtime. But still we got some good running in and it's good to be back in the car again.

James Allison: It was a productive day both in the morning and the afternoon, taking the opportunity that winter testing grants us to explore the car thoroughly, in ways that are near-impossible once the racing season starts. We tested the new prototype tyre with Lewis in the morning, which was trouble-free, and ran through set-up changes with both drivers. It was an interesting day, because it got quite gusty at various points. That was useful for us, learning how to get the best from the car as the wind picks up. Tomorrow, we will continue to explore the basic behaviour of the car, before focusing more on performance on the final day of testing.

Ferrari

Sebastian was first to drive, carrying out an installation lap shortly after 9. Then the German went back out on a prototype C2 Pirelli tyre, designed specifically with the Dutch Grand Prix in mind. The Zandvoort track's unusual surface and its banked section meant that the sport's sole tyre supplier has opted to produce a compound specifically for that event and all teams were able to try it. Then it was back to the standard C2 compound as the job of assessing the car continued. In the second part of the morning, the German switched to the C3 tyres with which he set his fastest time of 1:18.113. He completed 84 laps, or 391 kilometres.

During the lunch break, the car was reconfigured to suit Charles. Once again, after an installation lap, the car was fitted with the Zandvoort C2 prototypes so that Leclerc could also sample them. He then switched to the standard C2. The Monegasque driver tackled some aero work and did some long runs before switching to C3 tyres for the final hour, when he set his best time, stopping the clocks in 1:18.244. He did a total of 80 laps, equivalent to 372 kilometres.

For the second and penultimate day of the test, Sebastian will be at the wheel of the SF1000 all day, his last in the car before the start of the season. On Friday, Charles will drive.

Charles Leclerc: "It was nice to be back in the car today, even if the wind that intensified in the afternoon complicated our programme, because it meant the data we gathered, relating to the handling of the car, could not be relied upon completely.

"At least we managed to cover a good number of laps, moving forward in terms of our understanding of the car. Then, finally, in the closing minutes, the wind died down and I was able to do a run that was more reliable in terms of feedback. At the moment, it's impossible to make comparisons with our rivals.

"Over the next two days, we will continue to concentrate on ourselves to try and get all the potential out of the car."

Red Bull

The first day of Formula One's second 2020 pre-season test saw both Alex and Max in action at the Circuit de Barcelona-Catalunya. Alex kicked-off the first day of running in the morning, with Max taking over in the afternoon. Continuing the pattern from the first test, the Team focused on testing the RB16 under a variety of set-up conditions. Today featured the debut of Pirelli's experimental tyre, which may be put into use at the Dutch Grand Prix to cope with the high-speed banking of Zandvoort's final corner.

Alex Albon: "We had a small issue with the suspension and lost a bit of time so this morning was a little frustrating - but we did so many laps last week we're still on a good footing and haven't really fallen behind our plan. Even though we didn't get as many laps as expected, the car was feeling pretty good and already an improvement on how it was last week. Obviously, this week there will be more of a focus on performance, and we've taken some steps in the right direction. We're trying to get the car into the best window. It's already in a good place but there are little pieces of the puzzle we're trying to fit together throughout the test, getting us ready for Melbourne."

Max Verstappen: "Today I tried the new Pirelli tyre compound, but overall we were trying lots of things, learning how the car reacts under various circumstances, so when we reach Australia, we'll know what to expect. We won't know how good we are until we get to Melbourne because testing isn't about setting lap times but trying new and different things. I stopped on track just before the end of the session but we're not concerned and overall it was a positive day. We have a lot of grip but so do the other cars so let's see what happens when we go racing."

Head of Race Engineering, Guillaume Rocquelin: "This morning we had an issue with the suspension, which cost us some time. That's a bit of a shame but things like this are the reason why we have testing. Once that was addressed, we ran without any problems and completed a good number of laps. Max's stop at the very end of the day is also something we understand and is not a concern. We were running a similar format to last week, trying out lots of set-up and suspension changes. Max also tested the new tyre that will potentially be used at Zandvoort and we have another set available that Alex will probably use tomorrow. Overall, we had a very good day, completed a good number of laps and learned some lessons."

McLaren

Carlos Sainz: "Today we focused our morning on trying to understand some new aero parts for the car. The programme was very intense and changing the parts around meant we didn't get to do as many laps as last week, but we completed the run plan as intended. All the back-to-back testing was important and all the data gathered is going to be very useful to understand the car. All in all, a good day."

Lando Norris: "A good day, we did a lot of shorter aero runs to get a better understanding of the balance of the car. We changed the car a bit since last week in the areas we felt we had to improve on, and the set-up was also slightly different. Because of that, we still needed to do a few more aero runs. It was another day of trying to learn more about the car, get a good feeling as a driver, and get some laps on the board.

"Overall, the day was productive, and we did pretty much everything we needed to on the run plan. Today was more about testing parts and the next two days will be more about setting up the car."

Andrea Stella, Racing Director: "We had another positive day today. The conditions were a little bit trickier than the previous days, but we were still able to go through our programme and gain accurate information. We had several test items to check and validate, which we did diligently thanks to good reliability. Today's target wasn't mileage, but some upgrades and set-up options. We look forward now to completing the test as efficiently as we have so far. We plan to look a little bit more into performance and into long runs over the next couple of days."

AlphaTauri

Pierre Gasly: "We had a little issue this morning which compromised our session. For sure it wasn't ideal as we had planned more laps and we lost some mileage, but these things happen, and we recovered as much as we could in the final hour. It was an intense end to the session as we explored different setup directions for the car with the little time we had. There were a couple of interesting things which Daniil continued working on this afternoon. We'll try to maximize every opportunity we have left on track to learn more about the car, I feel there's a lot more to come, but everyone has the same amount of track time so we need to be as efficient as possible."

Daniil Kvyat: "I think it was a productive half-day of testing for me. When it's a new car you always get interesting results, so I was able to understand it better every run I did. We continued with more setup changes you wouldn't normally have time for to try in free practice, to be able to see how the car reacts. We're not looking for pure performance yet, we're looking to fine-tune the balance and see how the changes behave in different corners; I think we can be happy with all of the data we gathered. We needed to tick as many boxes as possible today, especially now that testing is quite limited this year and I've only got one day in the car left."

Jonathan Eddolls (Chief Race Engineer): "With only a short period of time between the last test and the start of this one, the team worked hard on analysing the data gathered and feeding that into the setup direction and test plan for this week. We chose to split the day with Pierre driving in the morning and Daniil in the afternoon, but the test didn't get off to the flying start we had hoped for, as during the first run we noticed an issue on the data. On inspection, a pipe had come loose which cost us almost a couple of hours, so we had to compress Pierre's programme to a series of shorter runs across the C3 and C4 tyres. Because of the problem we had this morning, we moved the normal start of day aero rake running to Daniil's runs straight after lunch to gather the valuable aero data. After that, Daniil had a trouble-free afternoon and was able to cover some further setup tuning over both short and long runs before closing the day with performance runs on the C3 compound. There is a lot to look at overnight in preparation for the final two days to maximise our understanding of the AT01 before we head to Melbourne."

Toyoharu Tanabe (Honda F1 Technical Director): "After last week's work here in Barcelona, we analysed all the data from both teams and so we started this second test reflecting what we learned from that. Over these three days, we are continuing with function checks, as well as working on optimising the settings. We are now in a phase of fine tuning, in preparation for the season opener in Melbourne. Both our cars had to spend a while in the garage this morning and in the afternoon we focused on recovering from that delay. Despite that, everything seems to be progressing smoothly on the PU front."

Check out our Wednesday gallery from Barcelona, here.