|Raikkonen was much happier in the afternoon session|
Felipe Massa topped the morning session despite a flurry of spins, while Kimi Raikkonen was stranded in the pits with a gearbox problem. Raikkonen then headed the afternoon time sheet, but his fastest lap was a couple of tenths shy of Massa's morning best, and only fractionally faster than Lewis Hamilton's McLaren. "I struggled a bit to find the right settings," the championship leader said.
Hamilton split the Ferraris in the afternoon, but he was still shy of the fastest times of the day, set by Massa and the second McLaren - driven by his teammate Heikki Kovalainen - in the morning.
David Coulthard's best effort in the afternoon netted him the fourth best lap time of the three hours of Istanbul practice, but in the morning he had been slower than Mark Webber and 17th. Webber accepted the blame for crashing at turn six in the afternoon.
Robert Kubica's morning mileage was marred by a suspension problem, but he was sixth quickest in the afternoon, while Nick Heidfeld struggled with the cooler temperatures - and often damp track - to get heat into his tires and was 7th (morning) and 10th (afternoon).
The highlight of Timo Glock's Friday was a trip over the curbs which damaged his front wing, but he did narrowly beat his teammate to tenth best in the morning. Trulli regained his usual couple of tenths advantage in the afternoon, though, slotting into seventh.
Eighth and thirteenth for Kazuki Nakajima and Nico Rosberg respectively in the ultimate 90 minute session, and Nakajima was also quicker than his German teammate in the morning.
Ninth for Fernando Alonso in the afternoon, with Nelson Piquet a distant sixteenth. The gap between the teammates was similar in the morning as well, when Alonso was fourth quickest. "Encouraging for the rest of the weekend," the Spaniard said.
Jenson Button, fifth in the morning and 11th in the afternoon, was narrowly faster than the record-setting Rubens Barrichello in both sessions, as the pair ran with front wheel covers for the first time.
Giancarlo Fisichella's chances of rising above the last row of the grid were dealt a blow when he ran a red light in morning practice, incurring a three-position grid penalty. Adrian Sutil's afternoon was halted with a clutch problem, so he was well off the pace, but he did pip his teammate in the morning to 14th.
Istanbul is the final outing for Toro Rosso's STR2, and given that it appears the slowest F1 car in Turkey, the Faenza based team is unlikely to be lamenting the occasion. After Barcelona, Sebastian Vettel is happy that he at least appears back on the pace now.