Lewis Hamilton has topped the second practice session from the Circuit de Catalunya, setting a fastest lap time of 1:18.259. The Briton was one of many drivers who struggled to get a clean lap in, as the track conditions proved to be very tricky.
Red Bull will be encouraged by its pace after the second practice session, as its two drivers ended the session in second and third. Daniel Ricciardo was quicker than teammate Max Verstappen, slotting in behind Hamilton by just over a tenth of a second.
Ferrari will be deeply concerned following the session, as Kimi Raikkonen's day ended early with an engine issue. The Finn crawled back to the pitlane after his engine cut out with a puff of smoke, and a peculiar noise coming from the Ferrari unit.
Raikkonen's fastest lap put him in sixth place, behind his teammate Sebastian Vettel. The second Mercedes of Valtteri Bottas ended up between the two Ferrari's in P5, after he topped the first session on Friday morning.
Romain Grosjean and Kevin Magnussen demonstrated Haas' pace once again by ending up in seventh and eighth place. Grosjean's day wasn't completely smooth, as he spun out early on in the session at Turn 7, missing out on a chunk of running time.
Magnussen, who was eighth, received his first reprimand of the season following the opening practice session this morning for an "unnecessary" and "potentially dangerous" manoeuvre on the start-finish straight.
Stoffel Vandoorne was ninth for McLaren, who bring a radically upgraded front wing to the circuit this weekend. Sergio Perez rounded out the top ten, just ahead of his teammate Esteban Ocon, who missed out on the top ten by less than a tenth of a second.
There was an unsafe release towards the end of the session for Sergio Perez. The front left tyre wasn't fitted properly after a practice pitstop, and Perez got around half of the lap before pulling over out of fear that it would detach.
Fernando Alonso was twelfth and will be hoping to please his home crowd on Sunday. The Spaniard has finished inside the points at every race so far this year, with a fifth place in Australia and three seventh-place finishes to follow.
Nico Hulkenberg was P13, ahead of Pierre Gasly and the Sauber duo of Marcus Ericsson and Charles Leclerc. Both Sauber drivers have already scored points this year, and come to Barcelona twelve months on from when it bagged an eighth-place finish at Spanish venue.
Carlos Sainz followed the Saubers, while Brendon Hartley was eighteenth, as he was in the opening practice session. Occupying the final two positions on the timesheets were the two Willaims' with Lance Stroll heading Sergey Sirotkin.