Sebastian Vettel braved the cold conditions to lead Ferrari to the top of the timesheets on the second day of Formula 1 pre-season testing in Barcelona, beating Mercedes' Valtteri Bottas by three-tenths of a second.

After a quiet morning that saw teams complete limited running due to a low track temperature just a couple of degrees above zero, wider programmes were managed through the afternoon, with an additional hour being made available after the lunch break was cancelled.

Vettel managed to turn in a fastest lap time of 1:19.673 on the soft compound tyre to lead Ferrari to the head of the timesheets, beating Daniel Ricciardo's benchmark from the opening day of testing in the process.

Vettel completed 98 laps in total and finished three-tenths of a second clear of midway leader Bottas, who took second place for Mercedes, turning in 94 laps across the course of the day after teammate Lewis Hamilton sat out the running.

Stoffel Vandoorne impressed during his first extended run in the new McLaren-Renault MCL33 car on Tuesday, finishing third overall, six-tenths of a second back from Vettel.

Red Bull's Max Verstappen recovered from a minor fuel leak in the morning to finish the day fourth-fastest, just one-thousandth of a second back from Vandoorne, while Renault's Carlos Sainz Jr. slotted into fifth place.

Honda continued its solid start to life with Toro Rosso as Pierre Gasly enjoyed a trouble-free day en route to sixth place, managing 80 laps in the process.

Robert Kubica made his first F1 pre-season testing appearance since 2011 as he took over from Sergey Sirotkin at Williams in the afternoon session, and finished three-tenths of a second faster than the Russian to take seventh place.

Esteban Ocon's first running in the Force India VJM11 car saw him finish ninth-fastest ahead of Sauber's Charles Leclerc, who caused the first red flag of the day when he spun off at Turn 4 halfway through the day. Haas' Kevin Magnussen propped up the timesheets in P11, only managing 32 laps through the day.

The only other stoppage came 30 minutes later when an off-track excursion for Vettel left gravel across the circuit, requiring cleaning by the marshals.

Running resumes at the Circuit de Barcelona-Catalunya at 9 a.m. on Wednesday, with another eight hours planned through the day.