Daniel Ricciardo broke the unofficial track record at the Circuit de Catalunya-Barcelona in Formula One preseason testing on Wednesday, while McLaren again struggled with reliability issues.
Ricciardo was fastest with a time of 1 minute, 18.047 seconds on new hypersoft tires on his Red Bull, setting the best ever lap in Barcelona since the new track layout was introduced in 2007.
The time was more than a second quicker than Lewis Hamilton's pole position with Mercedes in last year's Spanish Grand Prix.
Felipe Massa had the previous record of 1:18.339 in a Ferrari in 2008 testing. Times set in testing are not officially recognized as track records.
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"It was a good bunch of laps today and I got a few quick ones in there, which was nice," Ricciardo said. "I would have liked to get into the 17s, but we'll save that for the racing."
Ricciardo had the most laps among all drivers with 165.
"I survived," said Ricciardo, who was scheduled to drive Tuesday but was forced to sit out because of a mild illness. "Today's was an optimistic run plan and I didn't think we'd get that much done but we got through all of it, so that was good. I think I'll sleep well tonight."
Hamilton, the defending F1 champion, ended more than three tenths of a second behind Ricciardo with the slightly slower ultrasoft tires on his Mercedes. Hamilton's teammate, Valtteri Bottas, finished with the third-fastest time.
Sebastian Vettel, who replaced Kimi Raikkonen in the morning session because the Finnish driver was "unwell," was fourth fastest. Raikkonen was able to return to the track in the afternoon but did only 49 laps.
McLaren's problems continued, with Fernando Alonso being stranded on the track because of an oil leak a day after teammate Stoffel Vandoorne twice had his runs interrupted by car failures.
McLaren opted to change the engine on Alonso's car after the leak, keeping the two-time world champion in the garage for most of the day. Alonso returned to the track for the final part of the session, completing only 57 laps, which was among the fewest of the 14 drivers who made it to the track. His time of 1:19.856 was still good enough for sixth fastest.
McLaren is using Renault engines this season after three struggling years with Honda.
Testing will continue until Friday. The season begins with the Australian GP in Melbourne on March 25.
The first four days of testing last week were hampered by bad weather in Barcelona, keeping cars in the garage most of the time.