Mercedes chasers go to war on super-soft tyres, but they’re still slower than Rosberg from yesterday on softs.
Vettel admits Rosberg's time on soft tyres was "awesome" as World Champions show their hand.
Kimi Raikkonen: "In a few days in Melbourne we will find out where we really are..."
Pastor Maldonado: "I still feel fresh after 140 laps!"
Nico Hülkenberg: "We were able to run reliably straight out of the box and that is very encouraging."
The team did a fantastic job to replace the power-unit ahead of today’s session.
The Russian completed 84 laps of the Circuit de Catalunya for a best time of 1:26.965.
Today's schedule consisted of aero analysis work in the morning, followed by setup evaluation in the afternoon.
Valtteri Bottas: "The day was busy and we know there is still more to come, I feel positive and the balance was good."
What exactly occurred when Fernando Alonso lost control and hit the wall last week is a mystery, but Ferrari driver Sebastian Vettel has some insight.
Felipe Nasr: "Again today we made another step forward, and we have to keep pushing in this direction."
Nico Rosberg set the quickest time of pre-season testing at Barcelona so far to top the second day of running at the Spanish track.
Manor's announcement that it intends to be at the Australian GP has given supporters of the team some encouragement, but there's still a long way to go before it becomes a reality.
James Allison: “This wasn’t an easy day for us as we spent time chasing our tails on an annoying reliability problems..."
Marcus Ericsson: “It was a productive day, and for me the best one of the pre-season so far."
Daniil Kvyat: “We were able to get quite a lot done and hopefully we’ll get more done tomorrow."
Felipe Massa: "The FW37 never showed a sign of an issue and this has been the case since we arrived at the first test in Jerez."
The F1 W06 Hybrid remained in the garage after lunch owing to an MGUK failure.
Romain Grosjean completed 75 laps over the course of a programme of set-up evaluations and performance simulations.
Just four more days of track action prior to the first race in Melbourne.
A hydraulic leak required a full power-unit change.