Better day for Red Bull
Red Bull finally managed to discover some "gold dust" in pre-season testing after previously unearthing nothing more than seams of woe.
After completing just 35 laps from the first five days in the RB10, Sebastian Vettel was able to chalk up a few miles on the second day of the second test at Bahrain's Sakhir circuit.
Although Vettel finished almost five and a half seconds adrift of rookie Kevin Magnussen in his McLaren, for the reigning four-times Formula One champion the lap time was irrelevent.
Instead, it was all about the amount of time spent behind the wheel as Vettel rattled off 59 relatively trouble-free laps, with only four other drivers ahead of the German on the lap charts.
Vettel, whose best time was a one minute 40.340secs, said: "We did more laps than we have done so far, and that's the big thing. That's encouraging.
"It was good to check the car, check the reliability, to get a proper first feel for the car, which feels okay, but there's a lot more to come."
Race engineering co-ordinator Andy Damerum added: "We had a good day.
"We did a tremendous amount of work overnight, and the guys really pulled it together, so much so we were ahead of schedule with the car this morning.
"We were able to fix the problem we had yesterday very quickly and there were no lingering issues, so we managed some good running.
"Every lap you turn gives you a huge amount of data, and that's gold dust, so we're pleased with what we got done.
"We're not out of the woods yet and we still have a lot of work to do, but the direction we've taken is looking like the right one."
It was the Mercedes-powered teams that occupied four of the top five places on the timesheet, spearheaded by Magnussen's hot lap.
The young Dane finished with a time of 1:34.910secs, 1.5secs clear of his closest rival in Force India's Nico Hulkenberg, and 2.5secs adrift of Vettel's pole position at the track last year.
Although the time was posted on the quickest of Pirelli's available tyres, the supersoft compound, it was still eye-catching.
After glitches earlier in the day, Magnussen eventually completed 46 laps and said: "It's a dream every time I get in the car.
"It's just so cool to be here and to be driving. I'm really enjoying it, and the team is doing a great job to help me. They're giving me really good guidance and making me feel confident."
Mercedes' Nico Rosberg brought out two red flags early on, but recovered to clock 85 laps, although that was still 21 adrift of the day high of 116 from Williams' Valtteri Bottas.
Only Ferrari's Fernando Alonso managed to split the Mercedes-powered marques in third, with the Spaniard completing 97 laps.
Caterham's Kamui Kobayashi promoted himself up to sixth late in the day with a run on the soft rubber to dip below one minute 40 seconds and edge ahead of seventh-placed Vettel.
Toro Rosso, who like sister team Red Bull have encountered numerous issues, started off strongly, only for another technical problem to bring Jean-Eric Vergne's running to a halt at 58 laps.
Sauber's Esteban Gutierrez completed 55 laps and was ninth quickest, leaving Lotus' Romain Grosjean and Marussia's Max Chilton at the rear.
Lotus are naturally encountering teething troubles with a car they launched on Wednesday, whilst Chilton only managed 17 laps due to a fuel-system problem that took a long time to resolve.