Lewis Hamilton delivered the faster speeds that Formula One rule changes had promised Friday, going under the racing lap record in the second practice session for the season-opening Australian Grand Prix.
The three-time world champion had the fastest time in morning practice and his afternoon time of 1 minute, 23.620 seconds eclipsed the racing lap mark held by Michael Schumacher at the 5.303-kilometre (3.295-mile) Albert Park Circuit.
Schumacher, the most successful driver here, set the record of 1:24.125 on his way to victory in 2004.
Ferrari driver Sebastian Vettel split the Mercedes cars, which posted the fastest two times in the opening practice earlier Friday, with his 1:24.167 in the afternoon session.
The Ferrari's were fast in pre-season testing and indications are they'll challenge when the season proper gets underway.
Vettel was less than one-tenth of a second in front of Hamilton's new teammate Valtteri Bottas, who replaced Nico Rosberg after the reigning world champion retired. Kimi Raikkonen moved up to fourth spot for Ferrari.
Hamilton, who won back-to-back world championships in 2014 and '15 and narrowly lost to Rosberg last season, completed 22 laps in the morning session and 17 in the afternoon.
The first practice was almost processional, with the two Mercedes leading as expected, followed by the two Red Bulls of Daniel Ricciardo and Max Verstappen and the two Ferraris.
The Ferraris moved into second and fourth while Ricciardo and Verstappen dropped to fifth and sixth, followed by Carlos Sainz of Toro Rosso and Romain Grosjean, who drove his Haas through the gravel during the session.
The new regulations for 2017 allowed for wider tires with more grip and durability, greater aerodynamics, bigger fuel loads and increased downforce and were designed to increase speed. The first two sessions have confirmed that is the case among the top contenders.
Williams rookie Lance Stroll set the first time of the season, the 18-year-old Canadian momentarily on top of the time sheets after his first flying lap in an F1 Grand Prix event. He was 13th in the opening session and dropped to 16th in the second, almost three seconds off the pace.
His teammate Felipe Massa was seventh-quickest in the morning but slipped to 14th in the afternoon, reporting mechanical problems as he slid off and stopped on the grass at turn 10. Massa completed five laps in the second session.
The second session, which was staged in sunny, mild conditions with the track temperature around 30 Celsius (86 Fahrenheit), was only 10 minutes old when Jolyon Palmer spun his Renault rear-first into the barrier.
McLaren had problems in testing in the offseason and former world champion Fernando Alonso's 12th in the second session was the team's best of the day.
The third practice is scheduled before the qualifying session on Saturday.
Australia GP practice two - top five
1 Lewis Hamilton (Gbr) Mercedes GP 1:23.620
2 Sebastian Vettel (Ger) Ferrari 1:24.167
3 Valtteri Bottas (Fin) Mercedes GP 1:24.176
4 Kimi Raikkonen (Fin) Ferrari 1:24.525
5 Daniel Ricciardo (Aus) Red Bull 1:24.650