Formula 1 returned to action this week at Jerez in southern Spain, with eight teams putting the first miles on their 2015 machines. Here's how each team fared across the four day test.

Mercedes:

Fastest lap: 1:21.982 (Nico Rosberg)

Laps completed: 516

Mercedes’ start to the campaign didn’t feature any headline-grabbing times but their consistency and reliability straight out of the box was highly impressive. Red Bull Christian Horner jokingly said the squad was ‘taking the mickey’ when Rosberg racked up 157 laps on Sunday. There were a few reliability niggles but they were relatively minor, while Lewis Hamilton’s spin on Wednesday occurred on a damp but drying circuit.

Red Bull:

Fastest lap: 1:23.338 (Daniel Ricciardo)

Laps completed: 164

Red Bull’s Jerez voyage was more productive than its 2014 outing but it was still far from clean. A couple of reliability issues cropped up and while Renault insisted that it was a ‘stupid part’ which can be fixed, it still cost the team time. Daniil Kvyat’s error a few laps into his testing programme effectively scuppered an entire day’s worth of running as he damaged the only front wing the team had at that stage. Nonetheless, the squad's decision to test in an interim 'camo bull' livery still raised a few eyebrows.

Williams:

Fastest lap: 1:22.276 (Felipe Massa)

Laps completed: 278

Mid-table in terms of lap times and mid-table in terms of laps completed. Williams’ start to the campaign was an understated one after they took the wraps from the FW37 on Sunday morning. Both Massa and Valtteri Bottas believe that the car is an upgrade on the FW36 which they piloted to third in the Constructors’ Championship.

Ferrari:

Fastest lap: 1:20.841 (Kimi Räikkönen)

Laps completed: 345

Ferrari undoubtedly stole the headlines by setting the pace on three of the four days and also ending the test with the fastest time, courtesy of Räikkönen. Sebastian Vettel urged caution despite Ferrari’s pace but Räikkönen expressed positivity about the SF15-T, particularly in comparison to the F14-T. Reliability was also good as the team achieved substantial running, despite early telemetry issues.

McLaren:

Fastest lap: 1:27.660 (Jenson Button)

Laps completed: 76.

McLaren completed the fewest laps and posted the slowest times as it renewed its alliance with Honda. But these are early days and whereas the trio of manufacturers in 2014 stepped from V8s to V6s, Honda is starting afresh following its absence. Both parties are encouraged that no major problems have been detected, with the limited running often down to minor issues that required a lengthy fix.

Toro Rosso:

Fastest lap: 1:22.553 (Max Verstappen)

Laps completed: 352

After a few early issues this was a productive test for Toro Rosso with the Italian outfit racking up 352 laps across the four day period. Most of the emphasis went on reliability and long runs, meaning that times were deceptive, as the team tried to help its rookie pairing wherever possible. Both drivers made minor errors, as expected, but they performed professionally and didn’t cause major problems.

Lotus:

Fastest lap: 1:22.713 (Pastor Maldonado)

Laps completed: 190

Lotus only fired the E23 Hybrid up for the first time on Saturday so for the car to hit the track on Monday morning was an impressive turn around by the team. The switch to Mercedes power wasn’t completely smooth as both Maldonado and Romain Grosjean lost time due to mechanical problems, but the pair described themselves as happy after sampling the car for the first time.

Sauber

Fastest lap: 1:21.545 (Felipe Nasr)

Laps completed: 380

After Sauber’s woeful 2014 campaign this was an encouraging test for the Swiss minnows. Both Nasr and Marcus Ericsson posted competitive lap times while insisting that they weren’t on glory runs, even if the C34 is lacking in sponsors. The only mechanical stoppage came when they performed a fuel system check while both drivers recovered after making errors, Nasr’s the most spectacular as he bounced across the grass at Turn 8 before halting in the Turn 9 gravel trap.