F1 BRITISH GRAND PRIX:LEWIS HAMILTON yesterday insisted there was more to come from his McLaren car at his home grand prix after he and team-mate Jenson Button were left languishing in midfield in the first two practice sessions ahead of the British Grand Prix.

With McLaren using the two sessions as a test bed for its version of the “blown diffuser” exhaust system which has given arch rivals Red Bull Racing the edge this season, it was left to Sebastian Vettel and Mark Webber to set the pace for the Anglo-Austrian team, Vettel dominating the first period and Webber leading the second despite electrical problems.

“Today we put on the new components, and I was well excited this morning,” said Hamilton, who ended the day in eighth and one and a half seconds adrift of Webber, while Button was 13th. “The feeling in the car was positive. I was actually surprised at the pace we had in the morning. We made some changes, but the changes we made to the car set-up actually didn’t make it better.

“So we’ve got to go back to the set-up we had earlier on, and start from there again. Hopefully tomorrow the set-up will be better to drive. But generally I think the performance of the car is good.”

Though their advantage hasn’t been mirrored in results, Red Bull Racing have outpaced their rivals all season, their trick exhaust system, which vents hot gases through the rear diffuser thereby boosting downforce, leading to quicker lap times and eight pole positions from nine outings.

McLaren, despite having their own ace up the sleeve in the shape of higher straight-line speeds, have been quietly developing a response to the Red Bull system and yesterday attempted a first run in anger with the new diffuser. Hamilton believes it has already made a difference, though he reserved judgment on its use in tomorrow’s race.

“When I got in the car they didn’t know how much downforce it was going to give us but I had a big grin on my face when I got to full throttle,” he said. “It makes a nice difference. I don’t know whether it makes as big a difference as perhaps they thought, but it’s something you have to tweak.

“I definitely feel we’ve made a step forward from Valencia,” he added. “This track is a bit like Barcelona, where you’d see nearly a second gap between ourselves and Red Bull. I don’t think we will be seeing that gap. I think tomorrow will be a lot closer.”

Last year Vettel strolled to an emphatic victory here – driving away from the field from pole to record an untroubled win – and yesterday the German was quickest in the morning session and third in the afternoon. “It was a pretty good today,” he said. “In the afternoon I spun and flat-spotted a set of hard tyres and had to wait a little longer and then I had an issue with the brake pedal but it was nothing serous.”

Webber, though, is convinced Hamilton’s assertion McLaren will show more this afternoon is accurate. “I don’t think they’re showing everything. I think they’re waiting to unleash the car tomorrow,” said the Australian, who spent much of the second session in the garage with electrical problems.

Ferrari, who introduced their diffuser in Valencia and who have more upgrades in the shape of improved front and rear wings here, saw Fernando Alonso go second in practice, splitting the Red Bulls, but the Spaniard was cagey as to whether he can match that result this afternoon. “We know we have to improve the car. It’s not enough at the moment,” he said. “Red Bull are a lot quicker than us at the moment, so we’ll try to get as close as possible tomorrow to have a good Saturday. I think it will be very close.”