• British Grand Prix

Vettel on top despite exhaust clampdown

Laurence Edmondson at Silverstone July 9, 2011
Sebastian Vettel pipped Fernando Alonso as the team finally got some dry running © Getty Images

Sebastian Vettel resumed his usual position at the top of the timing sheets during the final practice session at Silverstone for the British Grand Prix.

Despite Red Bull losing out in a debate over off-throttle exhaust blown diffusers just an hour ahead of the session, Vettel still went fastest with a 1:31.401, 0.063 seconds up on Fernando Alonso's Ferrari in second. Friday's wet weather pacesetter Mark Webber was 0.428 seconds off his Red Bull team-mate in third, although he spent a fair amount of the session in the garage and completed just 12 laps. Felipe Massa was fourth fastest 0.7 seconds off Vettel and Alonso.

The drivers' quickest times were set on soft tyres which were used for the first time this weekend after Friday's rain. However, the track was still lacking in grip and a couple of showers throughout the hour kept the drivers on their toes.

Williams' Pastor Maldonado hooked up a decent lap for fifth fastest ahead of the highest-placed British driver Jenson Button in sixth. Sauber drivers Kamui Kobayashi and Sergio Perez provided another couple of surprises on the timesheets in seventh and nint, split by Nico Rosberg's Mercedes. Paul di Resta rounded out the top ten for Force India.

Home favourite Lewis Hamilton was 13th fastest after another low-key session. The McLaren driver was caught up in the rain at his first attempt on soft tyres and then came across traffic towards the end of the session, suggesting his best is yet to come.

But much of the focus during the hour was on off-track activities as Red Bull boss Christian Horner went up to race control to argue his side on the latest exhaust regulation changes. Since yesterday the Renault engines in the back of the Red Bulls have been restricted to just a 10% throttle opening when the driver is off the gas, rather than the 50% it was running with FIA consent on Friday.

The change, which was instigated by a row in the FIA press conference yesterday between Horner and team principal Martin Whitmarsh, should limit the Red Bull's rear downforce under braking and could create reliability issues. But on the basis of Vettel's performance so far today, the hit might not be enough to unseat Red Bull from the top spot.