Silverstone, United Kingdom: Lewis Hamilton topped the times for Mercedes ahead of his teammate and championship leader Nico Rosberg in Friday’s second free practice session for Sunday’s British Grand Prix.

The 29-year-old Briton, champion in 2008, clocked a best time of one minute and 34.508 seconds to outpace German Rosberg by 0.228 sec on a warm and blustery day at Silverstone.

Spain’s two-time champion Fernando Alonso of Ferrari was third fastest, seven seconds down on the pace-setter, ahead of the two Red Bulls of Australian Daniel Ricciardo and defending four-time champion Sebastian Vettel of Germany.

They were both more than a second behind on one lap pace but showed improvements in relative competitive speed on the long runs in the latter stages of the afternoon session.

Hamilton seemed to suffer a serious engine problem an hour into the 90-minute session when he stopped out on the circuit. “Engine stopped,” he told the team by radio. “Says engine kill, no shifting.”

Hamilton managed only 14 completed laps in the session compared to Rosberg’s 35, but will have access to the championship leader’s data after the session. Rosberg leads Hamilton by 29 points in the title race.

Finn Valtteri Bottas was sixth fastest for Williams — having missed the morning session when his car was run briefly for only three laps by Susie Wolff, the first woman to take part in a Grand Prix for 22 years — ahead of Briton Jenson Button in the leading McLaren.

If Wolff, whose husband Toto is head of Mercedes motorsport, was bitterly disappointed to have her British Grand Prix practice session cut short by an engine failure she refused to dwell on her misfortune.

The Scot has another opportunity with her Mercedes-powered Williams team in Germany later this month and is still not giving up on her dream — admittedly still no more than a long shot — of becoming Formula One’s first woman racer since 1976.

“That’s racing. I’ve known over the years that it can be massive ups and then massive downs as well,” she told reporters in the Williams motorhome.

“I’ve still got Hockenheim. I’ve got to go out in Hockenheim and show what I can do because I didn’t get the chance to do that today. I’ve still got one more shot at it, so head up high.” On one level at least, Wolff’s mere four laps at Silverstone partially achieved at least one aim — to give young girls a role model and someone they can aspire to emulate in a sport dominated by men.

Until Friday, no woman had taken part in any stage of a grand prix weekend since Italian Giovanna Amati tried and failed to qualify with Brabham in 1992.

Italian Lella Lombardi, in 1976, remains the last woman to race in Formula One, even if there have been several in other series and notably in the United States.

“If there’s no role model out there doing it, for all the little girls who come to race tracks to watch or watch it on the TV, if they don’t see a girl out on the race track then they are not inspired to maybe want to do that themselves,” said Wolff.

“And that leads to the second problem that there are not enough young girls karting or starting at a young age ... sometimes in life you also just need a chance and I got that chance here at Williams.” AGE BARRIER Wolff took part in straight-line tests and drove in the simulator and showed sufficient potential and persistence — even if there will always be those who point to her husband’s influence — to be handed a one-off test in 2012.

That in turn led to a young driver test at Silverstone last July, putting her on track at the same time as other race regulars, and an enhanced role this season with two Friday practice sessions thrown in.

“Sometimes in life you just need that chance and its up to you to grab that chance with both hands and make something of it,” said the Oban-born driver who started racing under her maiden name of Stoddart.

At 31, Wolff is aware that time is against her if she is to break down more barriers but the Scot — who spent seven years in the German touring car championship (DTM) — argued that she still had everything to aim for.

“Sometimes a lot is made of my age but I would never have been ready for this chance in my early 20s,” she said. “For me everything has been working up to this point, to be ready to drive an F1 car.

“I’m conscious that I’m not the youngest but I’m also not the oldest. I’ve always said that I will keep going as long as I can see a path and an opportunity to achieve. As soon as I see there is absolutely no chance, I will be the first to turn around and say time to move on.” Hockenheim is a track she knows well from DTM and she hoped that would enable her to showcase what she could offer.

“I really want to use that opportunity to show, not to speak to everybody and say ‘I can do it’ but I want to show it. I think actions speak louder than words,” she declared to a throng of reporters gathered around.

“You can’t expect to be on the grid unless you show you are good enough to be on the grid. I am well aware of the fact that there are many talented drivers fighting to be on that grid.

“Until I’ve done a good job in Hockenheim I’m not willing to say too much about the future,” added Wolff.