Kimi Raikkonen set the fastest time of the second practice session for the Bahrain Grand Prix as Lotus unveiled its pace.
Having appeared to run heavy in the first session, Raikkonen was one of the last drivers to switch to the medium tyres and found plenty of time to go quickest despite running slightly wide at the final corner. Having been over 0.3s up through sector two, Raikkonen ended up edging out Mark Webber by just 0.030s with a 1:34.154.
Webber was less than 0.1s clear of his Red Bull team-mate Sebastian Vettel as the front of the grid remained close, with Fernando Alonso fourth, 0.0156 off Raikkonen's time. Paul di Resta continued Force India's impressive pace with the fifth quickest time and even Nico Rosberg in eighth place was only 0.5s slower than Raikkonen, while neither McLaren made the top ten.
The high temperatures meant the long runs were also a test of the cars' cooling systems, with Red Bull particularly focused on its brake cooling.
As the tyres started to drop off, drivers started to struggle more with the rear of their cars, with Felipe Massa flying wide at Turn 7 as he lost the rear at high speed. Again it was Lotus which looked strong on high fuel as it extended the runs of Raikkonen and Romain Grosjean to analyse tyre life.
Force India also appeared to be looking after its tyres well, with its long run pace indicating it could be ahead of McLaren and even a threat to Mercedes this weekend.
Esteban Gutierrez made another slightly embarrassing mistake as he clashed with Charles Pic. Pic was allowing Gutierrez through at Turn 8 but the Sauber ran wide and hit the Caterham's front wing with its front left tyre, giving Gutierrez an immediate puncture and forcing him to limp back to the pit lane.
Despite the incident, Pic was within 0.5s of both Valtteri Bottas and Gutierrez as Caterham's updates seemed to provide a step forward, while Max Chilton beat team-mate Jules Bianchi at Marussia after the latter sat out FP1.