After taking to the track for the first time last week in its one-off 'Disruptobull' livery for a filming day at Silverstone, Red Bull's 2018 challenger, the RB14, today returned to its familiar racing colour scheme as testing for the new season got underway at a cold (and late in the day, pretty wet) Circuit de Barcelona-Catalunya.

After 105 trouble-free laps, Daniel Ricciardo ended the day at the top of timesheet with a best lap of 1:20.179, set in the morning session on medium-compound tyres.

"That was... cold! But apart from that it was good," said Ricciardo. "In the morning when it was dry everything was fine but in the afternoon the conditions were really tricky. It's hard to get anything working with tyres in these temperatures, especially as they've also re-laid the surface. When the temperature is there it's good, but when it's cold there really isn't any grip! However, it was still a good day and we got over 100 laps done, with, I think, one run of 35 laps. So reliability was solid and hats off to everyone for that. Performance? Yeah, It's nice to see yourself at the top of the timesheets but in two-degree temperatures you really can't learn anything!"

"That was a good start to testing for us," added Head of Race Engineering, Guillaume Rocquelin. "The fact that this year we had the car finished ahead of schedule certainly helped I think; just having that deadline of last week's filming day meant we had to be able to fire the car up and run. And I think the value of that deadline shows in what we got done today, which is certainly the largest lap total for a first day of pre-season testing that we've had in some time. It's a validation of some of the changes we made over the winter. It was a good outing, we got a lot of laps under our belt and we had good reliability. That's all you can ask for. It is day one and we take nothing for granted, but overall, we're pretty pleased with what we achieved."

Mercedes completed the majority of its planned programme, gathering valuable aero and tyre data. Owing to cold temperatures throughout the day and rain after the lunch break the team decided to cut the running short midway through the afternoon.

Valtteri Bottas and Lewis Hamilton took turns at the wheel of the all-new W09, completing a total of 83 laps.

Bottas was the first behind the wheel in the morning session, completing the programme the team had planned. Hamilton's session in the afternoon was cut short as the weather changed for the worse and made it tricky to run representative configurations.

"Our first morning was very positive," said Bottas. "We got everything done that we had planned. The main mission for the morning was to gather aerodynamic data, so I was doing runs at constant speeds. I got a few practice laps for myself as well; but that kind of running was very limited. We didn't do any performance running, so I haven't pushed the W09 to its limits yet.

"The initial feeling of the car was good, it was behaving well. I couldn't point out any negatives compared to last year's car, only positives so far.

"It was really good to be back in the car; it felt like I haven't been away at all. It didn't take any time to get used to the car - that's a good feeling. Driving these cars is still hard work for the drivers, but I had a good training programme over the winter, so I felt physically prepared.

"The weather conditions today were a bit tricky with the cold temperatures. Neither the cars nor the tyres are made to be driven in five degrees Celsius. We ran two sets of Medium tyres. In these conditions it was difficult to get enough heat into them to get them working properly. That's been the main challenge of the day, but that's the same for everyone. The amount of testing we can do is limited so we have to make the most of it.

"It's great to be back in the car after three months off," added Hamilton, "but unfortunately we didn't get the chance to complete many laps today owing to the bad weather.

The track was very cold in the afternoon, meaning it was tough to get any sort of heat into the tyres. The tyres weren't really working in these temperatures, so I could not get a real feel for them.

I didn't really get the chance to push in the car and go up to top speeds as the conditions were so bad. It's hard for me to say a whole lot about the car because I did not drive it for a long time, but the initial feeling is good.

While Italy is freezing, the Barcelona area is not doing much better, even if the trees are already in blossom. After a sunny Sunday, which meant that Ferrari was able to comfortably complete its Filming Day, the "real" debut for the SF17H took place in plunging temperatures, with rain arriving towards the end of the session. However, by the end of the day, Kimi Raikkonen had completed 80 laps of the Catalunya Circuit, the fastest of them in 1:20.506 on Soft tyres. He worked through the first part of a programme that, over the course of this week, is given over mainly to acquiring data.

"The real problem, the only one today, was the weather," said the Finn. "My first impressions with the new car were OK, but it's still too early to make any judgement, especially given today's conditions. These tyres aren't designed to work at 8 degrees and it was difficult for everyone. As for the rest, our work had nothing to do with lap times and we just ran and changed a few things, trying to understand the car, which doesn't seem to have any faults. Now we must try and do more kilometres."

The first long run with the Halo protection fitted over the cockpit went off without any problems. "Compared to the tests we did in previous years, this time the Halo had been conceived as an integral part of the car design, which had not been possible before," added Raikkonen. "I didn't notice anything different to driving the car without the protection."

Renault was another team with two drivers on duty, Nico Hülkenberg and Carlos Sainz taking turns behind the wheel of the R.S.18.

The German put in 73 laps in the morning, running reliably to complete his full programme, with a best lap time of 1:20.547. Sainz ran in the afternoon, to a more limited programme due to increasingly inclement weather. He posted 26 laps with a best time of 1:22.168.

"It was a satisfying first morning in the car," said Hulkenberg. "Our plan today was to get mileage and laps under our belt and we managed to achieve that. It was a solid start with no major issues. I felt good in the car straight away but there are other factors to consider too; the track here has been resurfaced so there are fewer bumps and a lot more grip so it naturally feels a lot better behind the wheel. Certainly, we're a good step forwards from where we were this time last year, but we have a lot of work to do over the days ahead. We completed every detail of the first day's morning programme, so that's credit to the team for all their hard work."

"It's been an encouraging day," said Sainz, "if a bit frustrating for me because of the polar weather this afternoon! It was quite tricky out there and that meant I couldn't get a true feeling in the car. Every time I went out it took a while for the tyres to warm up and therefore I had to be quite cautious. I couldn't find the limit of the car today, so I'm looking forward to tomorrow and going again; hopefully with some better conditions so I can gather some better feedback. Despite the cold weather here, the effort from everyone has been superb."

"These are not ideal conditions for testing," admitted technical director, Nick Chester, "but nevertheless we completed a good tally of laps with the R.S.18 and initial impressions are favourable. Nico had a very strong morning with 73 laps completed. The car was reliable and behaved as expected in regards to design and our simulations. Carlos didn't get the rub of the weather this afternoon but did get an initial feel for the car. Overall, it's a solid start."

It was a challenging day for McLaren as Alonso began the session promptly at the start of the day's running, but only managed to complete six laps before a wheel nut issue led to him being pitched into the gravel minus his rear right wheel.

The associated repairs to what was ultimately a relatively minor issue took some time to complete on the first day of testing where spare parts are naturally at a premium. The car was ready shortly before the lunch break and Fernando managed to get out on track for a couple more laps before the morning's running concluded.

The scheduled programme for today included set-up changes and more garage time, after which weather conditions had become less than favourable – the temperature dropping dramatically and the track becoming increasingly wet. The team opted to continue running in order to gather essential data, albeit with a more limited programme than would have been possible in the dry.

"The first thing I thought when we had the wheel nut issue was that it was a good day for the media!" said Alonso. "It was a very small problem, but very obvious when you see a car in the gravel. In testing, there are cars in the garage in pieces and nobody sees that.

"We didn't plan to run much this morning in our scheduled test programme, and we had planned fundamental changes on the car over lunch, so the lack of morning running hasn't been a big handicap today. We reverted to our normal programme after lunch, and I'm the one that has done the most laps this afternoon while other teams have had issues.

"For me, I feel that today has been a very good start. The car felt good both here and in Navarra, and there's definitely strong potential. On the performance side, it's very early days to make an assessment, but everything seems to be in line with our expectations from the wind tunnel and the data that we had before coming to the test. At the moment, I think everyone is quite optimistic."

"While we have high expectations for our new partnership with Renault, we will not make any predictions now for the rest of the season after only one day of testing," said Eric Boullier. "This is the first day, it's still early days and we need to assess our car. We need to feed the information we've gathered back to Woking, and see how the car correlates with what has been drawn up in the design office.

"Naturally, we're learning about working with Renault – obviously the language is different, the switch positions are different, but it's still a V6 1.6-litre engine with energy to manage. There are different ways to do that, but so far so good. The relationship is good, and the troops in both camps are happy to work together.

"It's a shame we couldn't take full advantage of the afternoon session because of the weather, and the forecast is not looking good for the rest of the week. Dry running is more useful for testing of course, but even in the wet there are still a lot of systems to check on the car, so still a lot of work to do that could be done even if it's raining.

"The only downside from today is that our wheel nut issue cost us track time, but we've returned to running our programme and we're happy with the learning we're doing from our new package."

"It was a really positive day," said Brendon Hartley, who completed 93 laps on his way to posting the eighth best time of the day. "We had no issues at all but we stopped early because of the weather, it was almost icy conditions out there. Everything felt pretty good from out of the box, we had some test items that we didn't get to complete because of the weather, but getting through 93 laps on the first day of testing was a great start to the campaign with the new Toro Rosso-Honda (partnership).

"Balance-wise, we were pretty comfortable straight away but I still think there's potential to unlock. I'm really happy with how the day went, I think everyone probably struggled with tyres, but doing one corner slow the tyres drop out of the window and it was almost like an ice-skating rink. It's quite a challenging day to get the tyres working in the window all the time. I think we learnt a lot and set ourselves up nicely for the rest of the test, probably more so next week when the weather gets a bit better. The driveability of the engine is one of the best I've driven in a Formula 1 car, so it was really positive in all aspects. Absolutely no complaints from me."

"It's great to go testing after a long winter of preparation and get the new car running on track," added technical director, James Key. "I think the priority for today, and for this week, has been predominantly mileage accumulation for checking the reliability of the car itself, giving the drivers plenty of opportunity to learn about the car and to cover some ground with preparation for the start of the season. This is an important preparation period for the drivers, which they didn't get the opportunity to cover last year.

"We will also be going through the fundamentals of the new tyres, car set up, aero performance etc in this first week and we started this today in a positive way. We got through the majority of the test programme which was ultimately curtailed by the tricky weather conditions in the afternoon. However we covered a lot of laps with no major problems, we have worked well and proactively with our colleagues at Honda over the last 6 months and we can be pleased by the encouraging start we have made."

"I feel happy that we were finally able to bring the car on track here in Barcelona after a busy winter," said Toyoharu Tanabe, Honda F1 Technical Director. "We did not complete our entire planned programme for today, but that was simply because we did fewer laps than we could have done this afternoon, due to the very low temperatures and drizzle which affected track conditions. However, I am pleased with the work completed and 93 laps is a respectable total.

"Although we have only been working with Toro Rosso for a relatively short period of time, the development has gone ahead according to plan thanks to both partners communicating very closely together. I think we are all working very well as a team now and I appreciate the hard efforts made by all the staff in Italy, UK and Japan.

"Today, on the first day of testing, we went through all the usual function checks on the car, as well as the operational checking of the team's work flow, as we are obviously a new team with a new car. We have seven more days of testing and it is important to do as many laps as possible in that time, to develop the car as a package, focusing on being well prepared for Melbourne."

Check out our Monday gallery from Barcelona, here.