Sebastian Vettel made light of Red Bull Racing's concerns over engine concessions to post the fastest time of final practice at Silverstone, with team-mate Mark Webber backing him up in third place.
The Milton Keynes team shared the top four with Ferrari, as the Scuderia mixed it at the sharp end in the absence of McLaren, and Vettel only emerged on top by 0.063secs from Fernando Alonso. Webber, by contrast, was four tenths off the German after losing a lot of time in the pits, with Felipe Massa a further three tenths adrift as another wet-dry session spread the field out more than expected.
The hour-long session started on a dry track, but it wasn't long before the first spots of rain appeared, although it never became as heavy as witnessed on Friday, when both sessions were largely useless in terms of development running. That times continued to improve right to the final seconds showed that conditions were more conducive to planning for the remainder of the weekend, and Vettel only vaulted into top spot with minutes left on the clock.
The Red Bull team had been shocked to learn that, overnight, the 50 per cent throttle opening concession granted to all Renault engine users on Friday had been withdrawn, while Mercedes users had been allowed to retain the rules break that formed part of the heated discussion between team principals Christian Horner and Martin Whitmarsh. On track, however, it appeared that neither Vettel or Webber was adversely affected.
Ferrari, meanwhile, would have been happy to be getting between the blue machines, especially with the McLarens of Jenson Button and Lewis Hamilton back in sixth and 13th respectively. Neither Briton was on track at the very end of the session, but it is unlikely that they would have threatened Vettel or Alonso.
Into fifth place, therefore, came the surprise form of Pastor Maldonado, whose Williams briefly topped the times before being gradually pushed back by faster rivals. The Venezuelan still ended the session half a second clear of Button, however, with Kamui Kobayashi - keeping his car in one piece this time - Nico Rosberg, Sergio Perez and Paul di Resta completing the top ten. The second Mercedes of Michael Schumacher improved to eleventh on his final lap, and could have gone better but for a lock-up, but also enjoyed an early spell at the head of the times as the Three Pointed Star suggested it may be in the ascendancy following the overnight FIA directive.
Schumacher demoted Adrian Sutil and Hamilton with his late lap, while Rubens Barrichello and Vitaly Petrov rounded out the top five, Renault appearing to struggle with Nick Heidfeld only 18th and narrowly ahead of the similarly-powered Lotus cars of Heikki Kovalainen and Jarno Trulli. Debutant Daniel Ricciardo, meanwhile, out-paced HRT team-mate Tonio Liuzzi in the battle for 23rd and 24th.