Mercedes drivers Lewis Hamilton and Valtteri Bottas continued to set the pace on Friday at the Circuit de Barcelona-Catalunya.
Just as he had in the morning session, Hamilton finished the second practice on 1:20.802s putting him narrowly ahead of his team mate Valtteri Bottas.
With the move to soft tyres, Ferrari managed to close the gap to their rivals. However they were still playing second fiddle to the Silver Arrows in the run-up to Sunday's Spanish Grand Prix.
Mercedes had taken a leisurely approach to the start of FP2, allowing Ferrari to set the early pace after lunch. Kimi Raikkonen went top with a time of 1:23.143s on the medium tyres, but that lasted only until Bottas made his first appearance and went 0.081s faster.
Hamilton's first run of the session was squandered when a gust of wind saw him run wide at turn 12. Several other drivers including Bottas were also caught out by the increasing crosswinds, and Max Verstappen had a particularly wild run across the gravel at turn 10.
A move to the soft tyres after half an hour resulted in a major improvement in the lap times. Vettel's contribution of 1:21.220s was almost two seconds faster, with Raikkonen promptly shaving a further tenth off. However once the two Mercedes drivers came back out, Hamilton and Bottas quickly re-established themselves on top.
After the midway point of the 90-minute session, attention turned from qualifying simulations to long-distance runs. Mercedes' advantage at the top was unchallenged, while Raikkonen finished the day in third ahead of his team mate who had a late run across the gravel in turn 4 after being caught out by another gust.
Verstappen also survived another off-track excursion at the chicane to finish fifth fastest ahead of his Red Bull team mate Daniel Ricciardo. There was an impressive showing from Renault, with Nico Hulkenberg seventh fastest ahead of his team mate Jolyon Palmer. Rounding out the top ten were Williams' Felipe Massa and Toro Rosso's Carlos Sainz.
Sainz was responsible for a brief red flag one hour into the session. He ran wide onto the kerbs at turn 9, shaking some bodywork loose from the car which meant the marshalls needed a stoppage to clean up the debris.
After his disastrous morning, Fernando Alonso returned to the track in his repaired McLaren half an hour into FP2. However he reported that the McLaren was even slower than it had been before, and ended the day over three seconds off the pace at the bottom of the timesheets. He did however successfully complete 21 laps following his latest power unit change.
Free Practice 2 results