Kimi Raikkonen of Ferrari put in the fastest laps at the Circuit de Catalunya on the outskirts of Barcelona, Spain on Thursday as teams tested their wet and slick tires on the fourth day of testing.

Raikkonen recorded the best time with a lap of one minute, 20.872 seconds, using slick tires after testing wet tires on the artificially soaked track earlier in the day. He was almost a second faster than Max Verstappen of Red Bull, who had some of the faster times in the wet conditions.

It was the second time in three days that Raikkonen has topped the timesheets. He edged three-time Formula One champion Lewis Hamilton of Mercedes on Tuesday, his first day behind the wheel in winter testing.

"I didn't pay attention to what the other teams were doing, nor the lap times, because at this point, it means nothing," Raikkonen said. "I've got the feeling that we learned some lessons from last year and, at the moment, we can't complain about how testing has gone so far."

Boost from Bottas

Valtteri Bottas seems to be the right man to replace the recently retired Nico Rosberg at Mercedes. He was the quickest on the third day of testing on Wednesday at 1 minute, 19.705 seconds, the fastest time ever recorded on the Barcelona circuit since layout changes were made at the track.

But Bottas was only eighth fastest on Thursday after Mercedes had to deal with a mechanical failure in the morning session, one that prevented Hamilton from running. 

"Electrical fault kept us in the garage this morning, so I've decided with the team not to drive today as I wouldn't have learned much," Hamilton wrote on Twitter. "Shame not to drive but it's been a great few days. The guys have done an awesome job. Can't wait to be back in the car next week!"

Another Mercedes-Ferrari battle in the making

The eight days of preseason testing this month, the second four of which will come next week, is the first impression Formula One racing teams can give. Mercedes and Ferrari definitely gave a good first look, with fractions of seconds separating the two teams on the time sheets on days two and three.

Mercedes has dominated the sport the last three years, securing the constructors and drivers championships from 2014-2016. But Ferrari may see an opening after Rosberg's retirement - Rosberg and Hamilton have comprised the top two in the drivers standings in each of the last three seasons. Ferrari has not won a constructors championship since 2008, and Raikkonen was the last Ferrari driver to win a drivers championship in 2007.

Meanwhile, the Red Bull team is trying to get back into the title picture, but have struggled with technical and exhaust issues in the first week of preseason testing. Haas has been busy with their testing as well, with Kevin Magnussen and Romain Grosjean each putting in 118 laps on days two and four respectively and each finishing fourth on both days.

"It's been a productive day for us," Grosjean said on Thursday. "We managed to get some wet running, inter running, pit stop practice, dry running, and trying a few setup changes that we had thought about overnight. The car is getting better and better."

The first race of the season is the Australian Grand Prix at the Melbourne Grand Prix Circuit on March 26.

dv/es (AP, Reuters)