Jenson Button put his McLaren on top of the timesheets during the second free practice session of the 2012 Spanish Grand Prix.
The Briton suffered heavy understeer early in the session; he was heard saying on the team radio: “Unbelievable understeer, unbelievable understeer”.
Sebastian Vettel kept Red Bull’s strong showing as he clocked the second fastest time, followed by Rosberg in the Mercedes.
Lewis Hamilton was half a second slower than teammate Button, he finished the session in 4th, ahead of Kimi Raikkonen’s Lotus in 5th.
Romain Grosjean ended up in sixth, with Mark Webber, who had an off moment during the session, in seventh and Michael Schumacher in 8th.
Kamui Kobayashi continued Sauber’s impressive pace as he managed the 9th fastest time, more than a tenths faster than Nico Hulkenberg who wrapped up the top 10 in the Force India.
1. Jenson Button McLaren-Mercedes 1m23.399 2. Sebastian Vettel Red Bull-Renault 1m23.563s + 0.164 3. Nico Rosberg Mercedes 1m23.771s + 0.372 4. Lewis Hamilton McLaren-Mercedes 1m23.909s + 0.510 5. Kimi Raikkonen Lotus-Renault 1m23.918s + 0.519 6. Romain Grosjean Lotus-Renault 1m23.964s + 0.565 7. Mark Webber Red Bull-Renault 1m24.065s + 0.666 8. Michael Schumacher Mercedes 1m24.080s + 0.681 9. Kamui Kobayashi Sauber-Ferrari 1m24.214s + 0.815 10. Nico Hulkenberg Force India-Mercedes 1m24.365s + 0.966 11. Felipe Massa Ferrari 1m24.418s + 1.019 12. Sergio Perez Sauber-Ferrari 1m24.422s + 1.023 13. Pastor Maldonado Williams-Renault 1m24.468s + 1.069 14. Fernando Alonso Ferrari 1m24.600s + 1.201 15. Paul di Resta Force India-Mercedes 1m24.688s + 1.289 16. Jean-Eric Vergne Toro Rosso-Ferrari 1m24.733s + 1.334 17. Daniel Ricciardo Toro Rosso-Ferrari 1m24.769s + 1.370 18. Bruno Senna Williams-Renault 1m25.047s + 1.648 19. Heikki Kovalainen Caterham-Renault 1m26.296s + 2.897 20. Vitaly Petrov Caterham-Renault 1m26.740s + 3.341 21. Timo Glock Marussia-Cosworth 1m27.314s + 3.915 22. Charles Pic Marussia-Cosworth 1m27.664s + 4.265 23. Pedro de la Rosa HRT-Cosworth 1m28.235s + 4.836 24. Narain Karthikeyan HRT-Cosworth no time