Catalonia: Lewis Hamilton fired a warning to his title rivals Monday with the Mercedes man pipping Ferrari`s Sebastian Vettel on the opening day of pre-season testing in Barcelona.
Vettel topped the timesheets in the first session but the Briton Hamilton, taking over the wheel of Mercedes` imposing 2017 car from new teammate Valtteri Bottas, clocked the day`s best lap of 1min 21.765sec.
The Finn Bottas, world champion Nico Rosberg`s replacement at Mercedes, had topped the times at one stage in the morning but slipped to only sixth-fastest overall after Hamilton stepped into the cockpit.
With radically new rules the 2017 F1 cars are wider and more powerful than their predecessors.
And combined with Pirelli`s wider tyres their extra oomph was plain to see in Barcelona with the fastest lap time for the entire eight days of last year`s testing lowered several times on day one.
Mercedes` daunting reliability was underlined by the German constructor`s car completing over 150 laps.
But Ferrari fans will take heart from Vettel, in action in both sessions, also putting in the miles with 128 laps.
And Felipe Massa, back in business for Williams after flirting with retirement, was another enjoying himself at the Montmelo circuit.
The Brazilian completed 103 laps and posted the third-fastest time.
But the pre-season testing woes that have haunted McLaren returned, with the once all-conquering British team spending more time in the pits than on the track.
Fernando Alonso had to wait over seven hours before putting his first timed lap on the board.
The Spanish two-time former world champion eventually mustered 29 laps in front of his home supporters -- albeit a mammoth three seconds slower than Hamilton.
American team Haas will take away plenty of positives from their performance with Kevin Magnussen producing the fourth-quickest lap.
But Red Bull had issues, with Daniel Ricciardo only managing four laps before lunch, the Australian making up for lost time in the second stint to post the fifth-fastest time.
This was the first of four days testing this week, with another four-day session starting next Monday, ahead of the opening Australian Grand Prix in Melbourne on March 2.
