MONTMELO, Spain — Ferrari driver Sebastian Vettel got off to a good start as the final week of Formula One testing began on Tuesday, setting the fastest time and running the most laps at the Circuit de Catalunya-Barcelona on Tuesday.
Vettel showed Ferrari's strength by finishing the day with a time of 1 minute, 20.396 seconds, two tenths faster than Valtteri Bottas of Mercedes. Max Verstappen was close behind with Red Bull, followed by the Mercedes of defending champion Lewis Hamilton.
"It was a good day's work," Vettel said. "We managed to get through our program, even if the conditions weren't always ideal, because of the wind."
Vettel ran 171 laps on Tuesday, 41 more than Verstappen, the driver closest to him on the lap charts. The only other driver to break the 100-lap mark was Marcus Ericsson of Sauber, with 120. Mercedes totaled 177 laps as Hamilton and Bottas split driving time.
"It's been a good day," Hamilton said. "We've got through everything we needed and put good mileage on the car. It's been productive."
McLaren, using a Renault engine this season after three dismal years with Honda, struggled with reliability problems as Stoffel Vandoorne was twice stranded on the track.
"We aren't overly concerned about the issues that we've faced today," team racing director Eric Boullier said. "It's obviously not the productive day we had planned, but the problems - a battery issue and a hydraulic leak - are the types of niggles that we almost hope and expect to face during testing."
Vandoorne ended the day with 38 laps, the fewest among the 13 drivers who were on the track. The Belgian driver had the third-fastest time overall in last week's tests.
Vandoorne's teammate, two-time world champion Fernando Alonso, ran a few laps on Monday on a "filming day," but he will not test until Wednesday. Practice is restricted in F1 but teams are allowed to take their cars to the track for a few brief periods for marketing and commercial purposes.
Sergio Perez caused a red flag after spinning in the morning session, and Verstappen stopped on the track in the afternoon because of an electrical problem.
The first four days of testing were hampered by bad weather and cold temperatures in Barcelona, keeping teams from making quality runs on a track that lacked enough grip and didn't reproduce the conditions expected during the season.
Hamilton was fastest last week with a time of 1:19.333.
Teams will test until Friday.
The season begins with the Australian Grand Prix in Melbourne on March 25.
Sauber said Tuesday it signed Tatiana Calderon as its test driver for 2018. The 24-year-old Colombian driver was the team's development driver last season.