Jerez, Spain (Sports Network) - Jenson Button from McLaren set the pace in Tuesday's first day of Formula One preseason testing at Jerez, despite a setback with the team's new MP4-28 early in the session.
Button's car suffered a fuel-pump issue following his third lap around the Spanish circuit. McLaren spent several hours working on the car before the 2009 F1 world champion returned to the track and later posted the quickest lap of the day in 1 minute, 18.861 seconds, which was almost one second quicker than his closest competitor, Mark Webber, who set a lap time in 1:19.709. Button turned in a total of 37 laps.
Webber completed 73 laps in Red Bull's 2013 car, the RB9.
"It was actually like a Friday practice session in some regards," Webber said. "We started understanding the tires, and there were a lot of positives. There's a bit of housekeeping we have to get on top of, but other than that, it's been encouraging."
Lotus' Romain Grosjean was third fastest (1:19.796), followed by Paul di Resta from Force India (1:20.343) and Toro Rosso's Daniel Ricciardo (1:20.401). Felipe Massa was sixth overall in Ferrari's F138 (1:20.536).
Mercedes also encountered a problem with its F1 W04 car during day one. Nico Rosberg completed three runs before an electrical issue caused the car to stop on the track. Unburned fuel in the exhausts subsequently ignited but did not cause any serious damage.
"At the start of winter testing, you often encounter small issues because the car you're running is a brand new design," Rosberg said. "We had an electrical problem this morning and, once we had found the root cause, chose to modify the parts to make sure it didn't happen again.
"Of course, at this time of year all you want to do is spend time in the car and get a feeling for how it's working, but these hiccups are just part of the game. During the laps I completed this morning, I had a good feeling with the car, and it felt solid."
Rosberg's completed just 14 laps, with his quickest lap time in 1:20.846.
Lewis Hamilton is scheduled to drive the Mercedes car on Wednesday for his first day of testing with the team. Hamilton left McLaren to join Mercedes following the completion of the 2012 season. Sergio Perez, who took over Hamilton's ride at McLaren this year, is expected to be in the car tomorrow.
02/05 14:01:05 ET