Jerez de la Frontera - Four-time world champion Sebastian Vettel has continued his positive start to life with Ferrari by going fastest again on a rain affected second day of pre-season testing in Jerez on Monday.
The German took nearly two seconds off the fastest time he set on Sunday to record a best time of 1min 20.984secs in his 88 laps.
Vettel's start to the new campaign is in stark contrast to his disastrous test in Jerez, during a troubled final season with Red Bull last year, when he lodged just 11 laps over two days.
"It could be worse, especially compared to last year at this stage," said the 27-year-old.
"We did a lot of laps, especially today. I think it is normal in winter testing if you see anything running a bit odd to take the time to stop and have a look which unfortunately takes time, but the new engines seem to work well even in these conditions."
Vettel will hand over the driving wheel on the SF15-T to teammate Kimi Raikkonen for the remaining two days of testing in southern Spain.
Reigning world champion Lewis Hamilton was only fourth fastest, but Mercedes were again leaders on laps completed as the Englishman did 91 before rain and a water leak from a failed part brought his afternoon to an early end.
McLaren's struggles with their new Honda-powered MP4-30 continued as Jenson Button managed just six laps to add to the same number Fernando Alonso completed on day one.
Red Bull were also left looking embarrassed when 20-year-old Daniil Kyvat damaged the only front wing they have with them in Jerez early on, which restricted the Russian to just 18 laps.
By contrast, 17-year-old Max Verstappen enjoyed a fruitful opening day of his Formula One career for Red Bull's junior team Toro Rosso as he went fifth fastest in 73 laps.
Sauber's surprising early reliability and speed was on show once more as Brazilian rookie Felipe Nasr was second fastest in racking up 88 laps just as teammate Marcus Ericsson had been on Sunday.
Finland's Valtteri Bottas also clocked up the miles with 61 laps as he went third fastest in the Williams.
The test in Jerez will be followed by two more four-day sessions in Barcelona later this month before the new season gets underway in Melbourne on March 15.