Looking at the lap times alone, it would seem that Ferrari is in the best form for the test session. In his first outing in scarlet, four-time world champion Sebastian Vettel topped the time sheets on both the first two days, putting in a hot lap that was nearly a full second ahead of the next closest car and stood as the fastest time achieved by anyone all week. Kimi Raikkonen took over on the third day, clocking the second fastest time of the day as well, and clocked not only the fastest time of the day, but the fastest of the entire four-day session.
Arguably even more impressive, though, was Sauber, which typically languishes in the middle or at the back of the field, but performed like a front-runner during the test session: Marcus Ericsson clocked the second fastest time on both the first and fourth days. His rookie teammate Felipe Nasr did the same on the second second day, but topped the leaderboards on day three.
The returning champions at Mercedes, however, clearly took a different strategy that focused on endurance and reliability instead of hot laps. Nico Rosberg reeled in 157 laps on the first day (two or three times as much as any other team) and 151 laps on day three, while Lewis Hamilton racked up 91 on day two and another 117 on day three. Even while it focused on going the distance, though, the German team still managed to land in the top half of the time sheets on each day.
Other front-running teams had a bit more difficulty, however. Daniel Ricciardo suffered from mechanical issues on the first day, completing only 35 laps for Red Bull. His new wingman Daniil Kvyat busted the front wing early on day two, and without a spare, the team was forced to keep running with an exposed nose. The team ran a good second or two behind the leader throughout the four-day test session.
Things didn't go so well for McLaren either as it dealt with some early teething problems from the new Honda engine. Fernando Alonso and Jenson Button, former champions both, only managed six laps apiece on the first two days, posting rather unimpressive lap times. Though Alonso completed a more respectable 32 laps on the third day and Button 35 on the final day, their best times were still far adrift off the pace.
Lotus had some trouble getting its car ready for the test session and missed the first day, but made some good (if unremarkable) headway on the subsequent days with Pastor Maldonado and Romain Grosjean behind the wheel. Williams and Toro Rosso were on hand for the entire session, racking up a good number of development laps and posting competitive (if not necessarily noteworthy) times on the leaderboard. Force India, however, was a complete no-show as its car wasn't ready for the test altogether.
Of course you can't tell from a practice session how a team will fare once the race season kicks off in earnest. And as Mercedes aptly demonstrated with its focus on going the distance, not every team is out to set the fastest times it can. But their first on-track performance of the year does give us what to look forward to, and as an early indicator, Ferrari and Mercedes - the most successful and most recent champions on the grid - are both looking in fine form.
Day One (Sunday):
1. Sebastian Vettel, Ferrari, 1m 22.620s, 60 laps
2. Marcus Ericsson, Sauber, 1m 22.777s, 73 laps
3. Nico Rosberg, Mercedes, 1m 23.106s, 157 laps
4. Daniel Ricciardo, Red Bull, 1m 23.338s, 35 laps
5. Valtteri Bottas, Williams, 1m 23.906s, 73 laps
6. Carlos Sainz Jr, Toro Rosso, 1m 25.327s, 46 laps
7. Fernando Alonso, McLaren, 1m 40.738s, 6 laps
Day Two (Monday):
1. Sebastian Vettel, Ferrari, 1m 20.984s, 88 laps
2. Felipe Nasr, Sauber, 1m 21.867s, 89 laps
3. Valtteri Bottas, Williams, 1m 22.319s, 61 laps
4. Lewis Hamilton, Mercedes, 1m 22.490s, 91 laps
5. Max Verstappen, Toro Rosso, 1m 24.167s, 73 laps
6. Pastor Maldonado, Lotus, 1m 25.802s, 41 laps
7. Jenson Button, McLaren, 1m 54.655s, 6 laps
8. Daniil Kvyat, Red Bull, No time, 18 laps
Day Three (Tuesday):
1. Felipe Nasr, Sauber, 1m 21.545s, 109 laps
2. Kimi Raikkonen, Ferrari, 1m 21.750s, 94 laps
3. Nico Rosberg, Mercedes, 1m 21.982s, 151 laps
4. Felipe Massa, Williams, 1m 22.276s, 71 laps
5. Pastor Maldonado, Lotus, 1m 22.713s, 96 laps
6. Carlos Sainz Jr, Toro Rosso, 1m 23.187s, 137 laps
7. Daniel Ricciardo, Red Bull, 1m 23.901s, 49 laps
8. Fernando Alonso, McLaren, 1m 35.553s, 32 laps
Day Four (Wednesday):
1. Kimi Raikkonen, Ferrari, 1m 20.841s, 106 laps
2. Marcus Ericsson, Sauber, 1m 22.019s, 112 laps
3. Lewis Hamilton, Mercedes, 1m 22.172s, 117 laps
4. Max Verstappen, Toro Rosso, 1m 22.553s, 97 laps
5. Felipe Massa, Williams, 1m 23.116s, 73 laps
6. Romain Grosjean, Lotus, 1m 23.802s, 53 laps
7. Daniil Kvyat, Red Bull, 1m 23.975s, 64 laps
8. Jenson Button, McLaren, 1m 27.660s, 35 laps