BARCELONA (Reuters) - Formula One wrapped up pre-season testing on Friday with Ferrari's Kimi Raikkonen setting the pace with the fastest lap yet around the Circuit de Catalunya.
The Finn's best effort of 1:18.634 seconds, on supersoft tyres in the morning, was the first below the 1:19 barrier and 0.804 seconds quicker than Red Bull's Dutch teenager Max Verstappen on the same tire compound in 1:19.438.
Raikkonen's team mate and four times world champion Sebastian Vettel had been fastest on Thursday in 1:19.024.
Before that, Mercedes had set the pace with Finland's Valtteri Bottas lapping in 1:19.310 on Wednesday. Triple champion team mate Lewis Hamilton was fifth fastest on Friday.
The early signs from testing, which can be deceptive, are that champions Mercedes, Ferrari and Red Bull remain on a different level to the rest but that last season's gaps have closed at the top.
The season starts in Australia on March 26.
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"Between the top three and the other ones it is between one second and 1.5 seconds, I think," said Haas team principal Guenther Steiner.
"There is no surprise that Mercedes and Ferrari and Red Bull came out better than everybody else. They have more resources to do more testing and that is what it is."
Haas driver Romain Grosjean brought out the red flags to stop the morning session twice on Friday, with troubled McLaren doing likewise as Spaniard Fernando Alonso had another tough session.
The team said the double world champion had experienced the same intermittent electrical shutdown that hampered Belgian rookie team mate Stoffel Vandoorne on Thursday.
"Various electrical components in the power unit and chassis were changed overnight, and the team are making further changes to eliminate variables and identify the source of the problem," said a spokeswoman.
Alonso was bottom of the timesheets, by more than a second, 4.1 seconds off Raikkonen's pace and with only 19 laps to his credit at lunchtime. He ended the day 11th with 43 laps.
(Reporting by Alan Baldwin in London; Editing by Alison Williams and Pritha Sarkar)