Team newcomer Lewis Hamilton - who claims to be loving life after leaving his former job in Woking for one in Brackley - set a blistering pace on Saturday, which was bettered by team-mate Nico Rosberg one day later.
Rosberg's 1m20.130s lap was set on the soft tyre and left him 0.3s clear of Fernando Alonso's Ferrari.
Sebastian Vettel, Kimi Raikkonen and others claimed that the Mercedes performance could not be taken as conclusive proof of its pace due to the uncertainty over what fuel load the F1 WO4 was running.
Alonso's final-day time was good enough for second overall with Hamilton's Saturday pace securing him third, ahead of Felipe Massa and Jenson Button.
While the long-run pace of both Sauber and Force India on Sunday was fractionally adrift of what Button's McLaren managed, both also showed good single-lap pace with Nico Hulkenberg and Adrian Sutil in the top seven.
Lotus once again suffered reliability problems and also lost Kimi Raikkonen for a day due to illness. This allowed reserve driver Davide Valsecchi to share the E21 with Romain Grosjean - the Friday pacesetter - on Saturday.
Williams introduced Red Bull-style sidepods as part of a major aerodynamic upgrade, leaving Pastor Maldonado and Valtteri Bottas delighted with the extra downforce on offer.
Friday's big-news story meanwhile was the late-night arrival of Jules Bianchi at Marussia, Luiz Razia having lost his drive over a sponsor shortfall.
The team many expect to lift the winning constructors' trophy in two weeks' time, Red Bull, failed to show its hand, Mark Webber's pace-setting time on the opening day the only indicator of the RB9's true speed.