The Australian managed to keep fellow countryman Mark Webber at bay, despite the Red Bull Racing driver being just a couple of tenths adrift of his junior rival and completing a session-high 101 laps in the new RB9.
“I think, in terms of consistency, it's great,” Webber said, “I'm very happy with the car and myself. I might have bombed a few laps here and there, but I've done 170 or more, which is a good total for the first two days with a new car.
“The car gives me the confidence to push pretty hard and that's always an indication that you have something you can build on. We've learned a lot more since yesterday and I'm sure that will continue tomorrow with Sebastian [Vettel]. I think we've put the car in a good position for him and hopefully he'll be able to push on from there.”
Nico Hulkenberg rounded out the top five for Sauber, squeezing himself in ahead of Lewis Hamilton after the Briton ran into reliability problems before the first couple of hours had run their course. Sauber focused on aero tests during the colder opening period, before switching set-up to focus on running with heavier fuel loads for the remainder of the day. Having run soundly throughout, however, Hulkenberg ran dry at the end of the session while the team conducted a fuel system check.
"It was a very good day, with Nico achieving all our goals,” head of track engineering Tom McCullough confirmed, “We continued our work on understanding the Pirelli tyres and while, without doubt, the temperatures will be different once we go racing, we still got to understand them well. The car was, again, very reliable, which gives us a solid basis.”
The same could not be said elsewhere in pit-lane, as Hamilton's problems compounded those already endured by Mercedes on day one, when Nico Rosberg suffered an electrical problem that took the rest of the allotted running time to rectify. The Briton had completed just a handful of lap more than his team-mate when he suffered a loss of rear brake pressure heading into the Dry Sack hairpin. Unable to sufficiently slow the W04 – locked fronts confirming his efforts to overcome the problem at the rear – Hamilton found himself bouncing across the gravel trap before coming to rest against that tyre barrier.
Although the driver was unharmed, the same could not be said for his car, which added suspension and bodywork damage to a work list that already included investigating the braking issue. As with Rosberg, Mercedes had to admit defeat well before the final chequered flag was waved, and will look for better fortune when the German returns to the cockpit on Thursday.
“We had a good start but then, unfortunately, we had a failure which brought our day to an early end,” Hamilton sighed, “These things happen and it's all part of testing – and, of course, it's better that we get these small issues out of the way sooner rather than later. The guys are working really hard to overcome them.
“From the few short laps that I completed this morning, my general feeling was very positive. I got a good understanding of where the base of the car is and, whilst we need to do work in certain areas, it was good to have some laps to get a feel for what those areas are. I've told the guys that we just need to keep pushing and I know that we all will be doing that.”
Ironically, Hamilton's best lap, which saw him sitting second overall at the time of his off, kept him ahead of the man who filled his shoes at McLaren, with Sergio Perez narrowly unable to better the Briton's 1min 19.502secs best as he made his first appearance with the Woking team.