Lewis Hamilton topped both Friday practice sessions ahead of the Chinese Grand Prix weekend, but Ferrari again showed signs of being able to challenge Mercedes over a race distance during the two 90 minute sessions.
Following Sebastian Vettel's victory in Malaysia, the big question heading to China was whether Ferrari could sustain its challenge to Mercedes' F1 hegemony. The times in first practice suggested the pendulum had swung back in favour of the world champions, but in second practice Kimi Raikkonen offered hope of a genuine battle emerging for the second race in a row.
Raikkonen's quick lap was within 0.5s of Hamilton's best, but it was the long-run pace that looked most impressive as his Ferrari proved quick and consistent on the medium tyres. Hamilton said afterwards that his medium tyres "did not feel too good", but the significantly quicker soft compound looks likely to be the tyre of choice if degradation of the front left is kept under control.
Both Sebastian Vettel and Nico Rosberg failed to impress on their hot laps, with Vettel 0.7s off team-mate Raikkonen and Rosberg running wide at the final corner on his soft tyre attempt. As a result Rosberg was a full second off the pace of Hamilton on a weekend when he needs to reassert himself in the in-team battle at Mercedes.
The laps of Vettel and Rosberg allowed Daniel Ricciardo to go third fastest in the Red Bull, although he was still over a second off Hamilton. Ricciardo was running a low-drag rear wing on the RB11, which helped mask the power deficit of the Renault engine but needs to be balanced against the extra strain the reduced downforce will put on the tyres. He was 0.4s quicker than team-mate Daniil Kvyat running the old rear wing, whose session came to an end in the barriers when his brakes failed at Turn 14.
Valtteri Bottas was seventh fastest for Williams while team-mate Felipe Massa failed to set a representative time after losing his car under braking for Turn 14. Massa was on his quick lap when the rear of the Williams stepped out under braking and grazed the barrier, knocking off the front wing endplate. The accident left Massa 17th by the end of the session and that allowed Jenson Button to creep into the top 10 with a time two seconds off Hamilton's best. Fernando Alonso was another 0.5s shy of Button in 12th, but the overall performance was positive for McLaren and Honda as they up the performance of the MP4-30 again this weekend.
The session also had a bizarre and unwelcome interruption when a spectator managed to gain access to the pit straight and sprint across the breadth of the track to the pit wall as a Force India exited the final corner. He was quickly apprehended by marshals and passed on to the police, but the intrusion will be a concern for the race organisers.