F1 testing: Bottas quickest, Vettel/Ferrari star again in Barcelona

Bottas posted a best lap of 1m19.705s in the morning session using ultra-soft rubber and Vettel lapped just 0.247s slower using the soft-compound Pirellis during the afternoon.

Vettel spent much of the day running on medium-compound Pirellis, setting his best time an hour-and-a-half after the lunch break.

His day did come to a slightly premature end when he stopped close to the start/finish line with nine minutes remaining, bringing out the red flag.

Lewis Hamilton performed a full race simulation after taking over from Bottas at Mercedes for the afternoon, sticking to medium and soft tyres and setting a best time of 1m22.175s on the latter compound.

His run was interrupted by two red flags however, the first for an off for Carlos Sainz in the Toro Rosso at Turn 4, and the second coming minutes later when Lance Stroll crashed his Williams.

After his day-ending spin on Tuesday and another off just shy of the lunch break earlier on Wednesday, the 18-year-old Canadian caused a third stoppage of the week when he went off and hit the barriers exiting Turn 5, damaging the front end of the Williams FW40.

The crash caused Williams to end its programme early for the second day in a row.

Despite his own late stoppage Vettel completed a day-high 139 laps, with Sauber man Marcus Ericsson the next most industrious driver with 126 to his name.

Hamilton completed 95 laps, giving Mercedes a combined total of 170 for the day.

Daniel Ricciardo (Red Bull) and Jolyon Palmer (Renault) stayed third and fourth respectively with their morning times, with Nico Hulkenberg making it two Renault drivers in the top five with half an hour to go after setting a 1m21.791s on softs when he took over the R.S.17.

Marcus Ericsson (Sauber) and Romain Grosjean (Haas) made use of the supersofts to go sixth and seventh fastest, followed by Hamilton, Stroll and Fernando Alonso's McLaren.

After his troubled first day in the Honda-powered MCL32 on Monday, the Spaniard enjoyed a smoother day of running on Wednesday as he completed 72 laps.

His best lap, a 1m22.598s, came during the middle of the afternoon on ultra-softs and left him 2.893s shy of Bottas's morning effort on the same tyre.

Sainz, Force India development driver Alfonso Celis and Daniil Kvyat, who sat out the afternoon after completing Toro Rosso's morning running, completed the leaderboard.

DAY 3 RESULTS: