Kimi Raikkonen fastest on penultimate day of F1 testing

BARCELONA, Spain (AP) While Ferrari driver Kimi Raikkonen posted the fastest time so far in Formula One testing, using the new ultra-soft tire on Thursday, world champion Lewis Hamilton spoke of his boredom accumulating laps.

Raikkonen raced around the Catalunya track on the fastest compound tires in F1 nearly half a second quicker than Williams driver Felipe Massa, who also ran on ultra-softs but only very briefly. Nico Hulkenberg and 18-year-old Dutch driver Max Verstappen were third and fourth, respectively.

Hamilton and his Mercedes teammate Nico Rosberg practiced race simulations on slower tires rather than going for speed, which was not much to Hamilton's liking.

''I don't want to do this long running,'' Hamilton said. ''It's boring going around and around and around, that's why I can't wait for the races.''

Medium tires favor reliability over speed, meaning Hamilton and Rosberg were not challenging the leading times as they logged 144 laps between them.

''I've done loads of mileage in races more, so I'm super ready,'' Hamilton said, looking ahead to the season-opening Australian Grand Prix in 17 days.

Rosberg was fifth fastest and Hamilton 11th, but he hopes to get a chance to try out the ultra-soft tires on Friday and get a clearer indication of the car's potential speed.

''We've not really pushed it to the limit so far in terms of putting the car on a knife-edge,'' Hamilton said. ''Hopefully tomorrow morning we'll get a bit of that.''

Rosberg did 81 laps in the morning - comfortably the most of any driver - as he focused on fine-tuning different aspects. Hamilton took over after lunch and took things a bit steadier, completing 63 laps.

''I kept everything the same all morning, fuel level, tires, so I could just change the car to get a really good feeling,'' Rosberg said. ''Every time I was going out with a different set-up just to try and learn about the new car, and with the conditions great as well, it was a really valuable experience.''

It was another tough day for Haas - the first American-led team in F1 since 1986 - the day after Mexican driver Esteban Gutierrez spent the whole day in the team garage because of a turbocharger issue.

All was going well for French driver Romain Grosjean until right at the end of the morning session, when he slid off a turn.

''I locked the front wheel and went straight, luckily we stopped before the wall,'' Grosjean said. ''The (engine) maps were not 100 percent perfect and I was struggling a bit with the car.''

Grosjean spun into the gravel early in the afternoon, and the session was stopped again. He managed to get back out for the closing stages, and totaled 78 laps before coming off the track a third time.

Verstappen posted the day's highest tally with 159 laps, the day after teammate Carlos Sainz topped the charts with 166 - underlining Toro Rosso's outstanding reliability.