Mercedes have carried their testing form into the Australian Grand Prix practice sessions, with Lewis Hamilton and Nico Rosberg topping the practice charts in Melbourne on Friday.

The first practice day of the season brought to life pre-race predictions of breakdowns and tentative steps into the brave new world of Formula One created by a raft of rule changes.

But the first breakdown came from the most unlikely of sources, Hamilton finding himself parked before he’d completed the first lap of the first session.

Hamilton’s car crawled through the first corners and stopped on turn nine, which his team said was a sensor calibration problem causing his engine to shut down.

He missed the entire first session as his car was winched out.

The Briton made up for lost time by putting his Mercedes to the top of the charts on his first lap with soft tyres in the second session.

His lap time of 1:29.625 stood through the day to stay fastest.  

The second practice times outstripped the first as teams switched to softer tyres, pushing their new cars closer to their limits.

Australian Daniel Ricciardo became the first driver to break 1:31 but was promptly outdone by Rosberg, charting a 1:29.782 lap with an hour remaining in the session.

Many drivers continued to spend time on the grass after the first turn – including Fernando Alonso, Kimi Raikkonen and Ricciardo – as they struggled to adjust to the aerodynamics of their new vehicles.

F1’s new rule changes for the 2014 season, including a switch to turbocharged V6 engines, continued to lead to teething problems on the track.

The new “power units” made by Ferrari, Mercedes and Renault have replaced the engine in the F1 lexicon but have caused headaches for every team.

The teams powered by Renault – most notably Red Bull Racing – struggled in testing and Ricciardo, in his first season with the reigning constructors’ champions, responded by spending long stretches on the Albert Park street circuit to kick in his new car, finishing sixth.

His teammate Sebastian Vettel spent more time on track than any others for the second session, edging Ricciardo into fourth.

Seven drivers with Mercedes power units finished in the top 12 in each session, ensuring their good reliability continued.

Ferrari showed they too had pace, with Fernando Alonso leading the charts at different stages before finishing third.

New Ferrari recruit Kimi Raikkonen threatened to spend the second session in the sheds after needing a push back through pit lane with an electronics issue, but recovered to be seventh.

Others with Renault engines struggled significantly.

Both Caterham drivers and Lotus’ Pastor Maldonado failed to chart a time all day while Romain Grosjean was amongst the slowest.

Grosjean ended the session with in the gravel, as did Force India driver Nico Hulkenberg.

-AAP