Highlights - British GP second practice
By Andrew Benson
BBC Sport at Silverstone
Mark Webber set the pace in Friday practice for the British Grand Prix as Ferrari and McLaren raised hopes Red Bull could face a fight here.
Ferrari's Fernando Alonso was second fastest, 0.392 seconds behind Webber and splitting the Australian from his team-mate Sebastian Vettel.
Alonso's team-mate Felipe Massa was fourth ahead of the Mercedes of Nico Rosberg and Michael Schumacher.
McLaren's Lewis Hamilton and Jenson Button were eighth and 13th.
Webber said he thought McLaren were disguising their true pace.
McLaren spent the day evaluating a raft of new parts which they hope will enable them to challenge Red Bull for pole position at a track where Webber and Vettel would be expected to dominate.
It remains to be seen whether the reality will match McLaren's hopes but it was apparent on Friday that Red Bull remain the favourite for victory on Sunday.
The Red Bulls were the fastest cars pretty much whenever they were on the track, and Webber eventually stopped the clocks at a scintillating one minute 31.234 seconds.
Webber said: "It was pretty good apart from an electrical problem at the end which was a bit of a shame.
"We missed some laps but the car seems to be going pretty well here.
There's still a lot of work to do - Button
"I think some other teams are sandbagging a bit but we're happy with our programme and looking forward to qualifying.
"I think McLaren aren't showing everything today. I think they're waiting to unleash the car tomorrow. Definitely expect them to come right back up to us tomorrow."
Key among McLaren's developments are a new front wing and
which increases downforce - and therefore cornerning speed - by directing the exhaust gases around the rear wheels and into the floor of the car.
Williams are also giving their blown diffuser a debut here, while Mercedes - who introduced it for the last race but had to abandon it after it over-heated the rear of the car - have fitted it again with extra insulation around the rear of the car.
Ferrari introduced their version of the device at the last race. They were analysing the performance of their
F-duct aerodynamic device
- a system pioneered by McLaren this year that improves straight-line speed.
The team decided to run it on both cars for the rest of the weekend after comparing the car with and without it on Friday.
Hamilton feels McLaren have made progress
Alonso said: "It's very difficult to quantify what is the difference now (between us and) Red Bull.
"Hopefully we are close to them or in front of them; we don't know.
"At the moment they are favourites for tomorrow but on a single lap in final qualifying anything can happen and then we will see what is the position we are and what we need to improve in the next races."
Red Bull, too, have some developments on their car - a revised diffuser and rear wing.
As well as the upgrades on their cars, the drivers were familiarising themselves with the new layout of the Silverstone track, with a new 'Arena' section added in towards the end of the lap.
A bump at the new Abbey right-handed kink where the old track joins the new and where cars like McLaren, Ferrari and Mercedes can go at 160 mph which is 10mph slower than the Red Bulls there, caused several drivers problems.
Among them was Hamilton, who ran wide there several times in his McLaren in the morning session, when he was second fastest to Vettel.
Most of the drivers were positive about the changes.
Hamilton said: "Coming into it I was biased as I loved the old circuit but now the new section turning right into Abbey is tricky. It's so fast. It's very complex - it's still very tricky."
Vettel praises Silverstone (UK only)
His McLaren team-mate Button said: "It's been weird for all of us turning right into Abbey instead of going left, it's a little bit bumpy there but I think the layout works."
Alonso described the new layout as "better, more fun and more safe".
Webber said the new section was "difficult" and "a challenge", adding that he liked the new Abbey very much.
"It's pretty solid, pretty quick," he said. "We expected it to be fast and it is. They got it right. I don't know if Hermann Tilke (F1's in-house designer of new circuits) did this track but whoever did they got the angles right to make it difficult."
Lotus's Heikki Kovalainen was the fastest driver among the three new teams, nearly 0.8secs quicker than Virgin's Lucas di Grassi.
Japanese Sakon Yamamoto, who has replaced Bruno Senna in one of the Hispanias for this race, was nearly 1.3 seconds off the pace of his team-mate, the Indian Karun Chandhok.
Only Lotus's Jarno Trulli, who managed only three laps in the second session as problems kept his car in the garage, was slower.
Button and Hamilton both enjoyed the reception they received from their home fans.
"It's great to be here, walking out there and having the fans cheer us when we walk into the garage is such a special atmosphere. It was a good start to the day," said Button.
Hamilton said: "The best part here is when you come out of the pit lane, you launch and you see so many fans on the right hand side, always waving to you. Around the track you can see people wearing the caps all around the place."
Highlights - British GP first practice