Sebastian Vettel resumed his place at the top of the timing sheets during final practice for the Chinese Grand Prix as he maintained his advantage over the McLarens ahead of qualifying.
On the softer Pirelli tyres he set a 1:34.968 to pip the fastest McLaren of Jenson Button by 0.208 seconds around the 3.4 mile track. Lewis Hamilton was 0.405 off the lead Red Bull but scuppered his chances of a quick hot-lap by running wide in the first corner and dirtying his only set of soft tyres.
Perhaps the biggest story of the session was Mark Webber's ongoing KERS problem in the No. 2 Red Bull. The official line from the team was that he had an electrical problem and he only completed five laps during the hour-long session. Judging by the on-board footage he did not use his KERS system and every time he returned to the pits the team donned rubber gloves to handle his car.
Vettel appeared to be using his KERS at some points of the session but whether it was working completely faultlessly was unclear. Nevertheless, the car is clearly quick at this circuit, making child's play of the medium-speed corners in sector two to make up for any deficiencies on the straights.
Another car that looks at home at Shanghai is the Mercedes, with Nico Rosberg setting the fourth fastest time after a promising Friday practice for his team. He set his soft-tyre time earlier in the session when the track was not at its best and appears to be at least equal to the two Ferraris - although it's worth noting that Fernando Alonso was making up for lost time after Friday's hydraulic problem. Michael Schumacher's pace in the second Mercedes is less clear as he ended the session ninth after a scrappy first lap on his fresh set of soft Pirellis.
Force India also appears to have a competitive package this weekend with Adrian Sutil and Paul di Resta finishing inside the top ten. However, they can expect to have stiffer competition in qualifying from the Renaults, Saubers and Toro Rossos, all of which have shown potential this weekend.