McLaren's racing director Eric Boullier has admitted that he felt an overwhelming feeling of relief following yesterday's testing breakthrough at Jerez.
The Woking-based constructor managed to complete just 12 laps over the first two days due to a recurring sensor problem, although Fernando Alonso successfully completed 32 laps yesterday morning.
"Jenson's final lap last night made us all feel happier, because we felt we'd cured the issues that had affected us on Sunday and Monday," Boullier told reporters. "It was a relief to see the car get out of the garage at 9am, and run without problems for several hours."
McLaren, who finished fifth in the 2014 constructors' championship, ended day three of testing at the bottom of the timesheets.
