Hamilton tests new Mercedes as F1 preseason begins in Spain

Mercedes drivers Lewis Hamilton from Britain, left, and Nico Rosberg of Germany, unveil the new F1 Mercedes W07 Hybrid car during the official team presentation at the Catalunya racetrack in Montmelo, just outside of Barcelona, Spain, Monday, Feb. 22, 2016. (AP Photo/Siu Wu)
Siu Wu/AP

BARCELONA, Spain (AP) Defending champion Lewis Hamilton was the first driver out on the track Monday as Formula One returned to action with preseason testing.

Hamilton didn't waste time trying out the new Mercedes that he will attempt to guide to a third consecutive championship this year. He was one of 11 drivers scheduled to test their cars on Monday, the first of four days of testing at the Circuit de Barcelona.

Four-time champion Sebastian Vettel, who came third last year, also was on the track with Ferrari, as well as Jenson Button, who is hoping to find a much-improved McLaren after dismal results in 2015.

Vettel and Hamilton exchanged the fastest times early in the session, with Valtteri Bottas of Williams in third. Hamilton was also the busiest, running more laps than any other driver in the morning session.

Hamilton's teammate Nico Rosberg will be driving for the first time on Tuesday, as will Button's teammate Fernando Alonso.

''It's just important to get a lot of mileage, to sign off all the reliability things, and to build a good understanding about your car and tires,'' said Force India driver Nico Hulkenberg, who will start testing on Wednesday. ''That's the most important things in these early days.''

The first day of tests – nearly three months after the season-ending Abu Dhabi Grand Prix in 2015 – started on a damp track and under overcast skies, with most teams spending time running installation laps to check for possible problems.

Mercedes has dominated the last two F1 seasons and – with no major regulation changes for 2016 – is expected to be the team to catch this year. The test sessions in Barcelona should indicate if any of its rivals have made significant gains – or if once again the fight will be for second place.

''Teams have not changed the concepts of their cars, so I expect the grid to stay quite similar to last year's,'' Force India driver Sergio Perez said. ''But you never know, once you get to Melbourne everything changes so quickly, so it will be quite interesting to see where everyone is.''

The final test sessions for the 2016 season are scheduled for March 1-4, also in Barcelona. The first of 21 races is on March 20 in Australia.

Most teams had already launched their new cars online and through social media, but some made their official presentation to the media on the pit lane, with drivers and team members posing for photos in front of cars before Monday tests got underway. Among them were Haas, the first American-led team in F1 since 1986, and Renault, which took over financially strapped Lotus. Mercedes and Force India also introduced their cars at the track.

A few cars had already been on the track ahead of Monday's test session, but only for promotional events pre-approved by FIA, the sport's governing body. Mercedes was one of the teams to get an early feel for its new chassis.

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