Lewis Hamilton and Mercedes laid down an early marker for the rest as they went quickest in first practice at the Spanish Grand Prix.
The Briton surpassed his 2016 pole position time as he set a 1m21.21s to lead team-mate Valtteri Bottas by 0.029s as the two Silver Arrows held a near-second advantage over the Ferraris.
With significant upgrades for almost every team and hard compound tyres which are expected to be of little use this weekend, the first 40 minutes was given to evaluating those updates on the orange-marked rubber.
That would not be the case for Fernando Alonso though, as is McLaren came to a smoky halt on the exit of Turn 2 having just left the pits for the first time due to another Honda engine failure.
Sebastian Vettel also hit problems as a gearbox problem saw him pull off just after the pit exit. Due to his location, however, he was wheeled back into the pit-lane and the Ferrari mechanics were able to get the German back out.
A switch to the more preferred medium compound for the final 40 minutes soon saw Mercedes vault to the top, Ferrari seemed content despite the large gap with Kimi Raikkonen marginally ahead of Vettel.
There were some signs of progress at Red Bull, with Max Verstappen almost matching the Ferrari pace in fifth with Daniel Ricciardo three-tenths behind in sixth.
Haas seized the initiative in the highly competitive midfield with Kevin Magnussen seventh and Romain Grosjean eighth. The Dane's advantage may well be due to him using the American team's updates having won a coin toss on Thursday, but an off at Turn 4 late in the session, seemed to indicate another mechanical issue.
Nico Hulkenberg was ninth for Renault, indicating a continuation of their strong single lap pace, with Carlos Sainz finishing the top 10 for Toro Rosso as he prepares for his home race.
Down the field, the two Force India's of Sergio Perez and Esteban Ocon were just outside what would be the points places on Sunday in 11th and 12th with Stoffel Vandoorne having one of his better sessions this season in 13th.
Williams looked to be focusing on their updates with Felipe Massa 14th and Lance Stroll 18th and Renault development driver Sergey Sirotkin once again stepped in, this time replacing Jolyon Palmer, but was again hampered by a mechanical issue as the Russian was 19th.
