Lewis Hamilton topped both Friday practice sessions at the Austrian Grand Prix, setting a new lap record in the morning before improving again by nearly 0.5s in the afternoon.
His best time stood at 1:05.483 by the end of the day, 0.147s quicker than title rival Sebastian Vettel in second and 0.216s faster than Mercedes teammate Valtteri Bottas in third.
Despite showing impressive pace on both short and long runs, it wasn't all plain sailing for Mercedes as both cars encountered issues during the afternoon session. Hamilton's first long run started well with a series of laps in the low to mid 1:08s on the ultra-soft compound and high fuel, but it was interrupted after just five laps with a faulty spark plug on an aging engine that will not be used in the race.
Once a new spark plug had been fitted, Hamilton returned to the track for a series of laps in the high 1:08s (similar to Vettel's long run on ultra-softs) but quickly complained that something felt wrong with the car. He returned to the pits asking his team to "take out a whole load of front wing" but did not return to the track before the end of the session. Combined, Hamilton's issues cost him 17 laps of running to Vettel but the lap times suggest he has a potentially quicker car over both short and long runs.
Bottas' best three sectors combined would have set the ultimate fastest time of the afternoon, but he couldn't hook them together and on his second quick lap had a spin through the gravel at Turn 5. The incident damaged the floor of his car and as a result his long-run times were no match for Hamilton's. He pitted for a front wing flap adjust to help balance the car, but his times did not improve dramatically as a result. Oddly, a second pit stop to switch from the ultra-soft compound to the slower super-softs saw his times dip into the low 1:08s, although that may have been related to a lowering of the fuel load rather than an improvement in the car.
Outside the top three, Red Bull had a disjointed session as Max Verstappen's car was delayed leaving the garage due to a loose brake connector and then spent a period of time back in the pits midway through the session for setup changes. He returned to the track to set a quick lap 0.349s off Hamilton and 0.041s quicker than teammate Daniel Ricciardo, who also spent an extended period of time in the garage between his low- and high-fuel runs before an MGU-H issue brought his session to an early end.
Kimi Raikkonen in the second Ferrari was 0.661s off Hamilton's pace before setting a series of underwhelming laps on the ultra-softs over a long run. He returned to the pits for a switch to the soft compound, which is not expected to make an appearance in the race, before another scrappy run well off the pace.
The remaining four places in the top ten had an unusual look, with no Mercedes customer teams and Fernando Alonso's McLaren -- powered by Honda's new spec-three engine -- in eighth. Alonso, who sat out of part of the session with a damaged floor and later spun at Turn 5, was 0.141s off Kevin Magnussen's Haas in seventh and 0.144s quicker than Nico Hulkenberg's Renault in ninth. Romain Grosjean rounded out the top ten in the second Haas ahead of Esteban Ocon's Force India, Stoffel Vandoorne's McLaren, Daniil Kvyat's Toro Rosso and Felipe Massa's Williams.
Carlos Sainz, in 15th, had one of the more dramatic moments of the session when he ran wide at Turn 9 and launched his car into the air as he attempted to rejoin the track from the grass. The incident caused damage to his car's floor and he returned to the pits with fluid dripping from the underside of his Toro Rosso -- his session over.
After his podium in Baku, Lance Stroll had to settle for the 16th fastest time ahead of Sergio Perez and Jolyon Palmer, whose bad luck continued with a session limited to just seven laps due to another technical issue on his Renault. The two Saubers rounded out the times, with Pascal Wehrlein 0.088s faster than teammate Marcus Ericsson but a massive 3.299s off the pace of Hamilton's best.
Betting on MOTOSPORTS? Bet365 are offering a 100% deposit bonus, up to £200 - find out more