Lewis Hamilton and Mercedes play down minor glitch in U.S. GP Practice Two

Mercedes have insisted that Lewis Hamilton’s early stoppage during Practice Two for the United States GP was merely precautionary – but admitted that unreliability remains an ongoing concern.

For the 14th time in 17 Practice Two sessions this season, Hamilton topped the close-of-play Friday timesheets at the Circuit of Americas by a mere three-thousandths of a second ahead of team-mate and title rival Nico Rosberg. But of greater concern to Hamilton will have been the hydraulic issue which meant he had to miss the final fifteen minutes of the session and limited him to just a couple of laps in race simulation mode.

"There was fluid on the floor, a leak of some kind, but I don’t think it is anything big. It's not helpful but Nico had a long run so as a team we will get data from that...and for me I'll get a better feel during the race,” Hamilton told Sky F1.

The Englishman has won the last four races to propel himself 17 points clear of Rosberg. But while the one-second gap to the third-placed Fernando Alonso indicates that Mercedes remain a class apart, the proximity of Rosberg in the timesheets suggest that Hamilton faces a particuarly close fight for victory this weekend.

“Nico is looking very quick, it is going to be very tough, but I am up for the battle,” added Hamilton. “There will be many battles this weekend but he is the closest on time.”

For Mercedes, who clinched the Constructors’ Championship in Russia three weeks ago, Hamilton’s minor glitch, coupled with the prospect of a close fight between their two drivers for victory, will only ratchet up the pressure on them to deliver bullet-proof cars for a fair fight.

 “It is quite a small thing, we don’t know quite what yet, but it was a precautionary stop,” said Executive Director (Technical) Paddy Lowe.

“Reliability is a really important factor in the championship overall but is becoming particularly so at the moment with the two drivers. There’s a big challenge for us to make sure we give them six car finishes in the final three races.”

Rosberg also suffered an apparent mechanical failure of his own, reporting a downshift problem over his car-to-pits radio midway through the session. But as the German sheepishly admitted afterwards, there was an innocent – if rather bizarre – explanation for the momentary alarm.

“I lifted my leg and hit my clutch pedal,” he admitted. “I had an itch on my foot and can you believe of all the things that could happen. So that turned into a bit of an issue.”