» Turkish Grand Prix 2nd Practice: Button maintains McLaren’s practice pace

Jenson Button maintained a McLaren on top of the timesheets at the Turkish Grand Prix weekend, marginally heading off Red Bull’s Mark Webber for the quickest time overall in the second free practice session, despite some reliability concerns for both Red Bull cars in the closing minutes of the 90-minute session.

McLaren looked set to maintain its initial superiority at the Istanbul Park circuit, with Button and Lewis Hamilton heading the timesheets after their opening times runs.

Midway through the session, the timesheets were doing their best Noah’s Ark impression, with the two McLarens leading from both Red Bulls, followed by both Mercedes GPs, Renaults, Saubers and Force India cars in the top-12.

As the track surface improved, so the timesheet order finally started to adjust, with Hamilton pulling out a 1:28.672 on a soft-tyre run, which was quickly eclipsed by Vettel’s 1:28.590.

Button would run faster just five minutes later with a 1:28.280, a time that would remain unchallenged for the rest of the day’s proceedings.

Mark Webber – now running without the team’s first iteration of the ‘F-duct’ which he had trialled in the morning’s proceedings – managed to lap quicker than his team-mate to take second place, but his afternoon came to a worrying end with five minutes’ running to go when smoke began to emerge from the back of his Renault-powered RB6 chassis. At the same time as the Australian parked his car, team-mate Vettel was making worrying noises about his climbing water pressure, giving the team a few headaches as they try to cure the reliability gremlins that have chosen to rear their heads this weekend.

Hamilton remained fourth-quickest at the close of the session, with Ferrari’s Fernando Alonso hauling his F10 to fifth overall after a slow start to the session.

Mercedes GP finished sixth and seventh overall, with Nico Rosberg finally out-pacing his team-mate in a practice session for the first time in a little while. The Silver Arrows were trailed by both Renaults and Felipe Massa’s Ferrari.

Turn 8 – the scene of Adrian Sutil’s big shunt in the first session – still seemed to be catching a few drivers out, one of them being three-time Turkish GP winner Massa, who snapped into a wild, slow slide that turned his soft tyres into 50-cent pieces.

Vitantonio Liuzzi also attempted to mirror his team-mate Sutil’s efforts in the morning with his own tail-happy moment at the daunting corner, but somehow managed to find the talent and reflexes to keep his mechanics from having to face a double repair job.

2010 Turkish Grand Prix Practice 2 Session Times:

	Driver	Team	Time	Laps
1.	Jenson Button	McLaren Mercedes	1:28.280	30
2.	Mark Webber	Red Bull Renault	+ 0.098	24
3.	Sebastian Vettel	Red Bull Renault	+ 0.310	26
4.	Lewis Hamilton	McLaren Mercedes	+ 0.392	32
5.	Fernando Alonso	Ferrari	+ 0.445	30
6.	Nico Rosberg	Mercedes GP	+ 0.634	22
7.	Michael Schumacher	Mercedes GP	+ 0.694	22
8.	Robert Kubica	Renault	+ 0.945	34
9.	Vitaly Petrov	Renault	+ 1.221	36
10.	Felipe Massa	Ferrari	+ 1.340	26
11.	Adrian Sutil	Force India Mercedes	+ 1.349	16
12.	Nico Hülkenberg	Williams Cosworth	+ 1.707	17
13.	Kamui Kobayashi	Sauber Ferrari	+ 1.773	34
14.	Pedro de la Rosa	Sauber Ferrari	+ 1.896	34
15.	Sébastien Buemi	Toro Rosso Ferrari	+ 2.106	32
16.	Vitantonio Liuzzi	Force India Mercedes	+ 2.347	28
17.	Rubens Barrichello	Williams Cosworth	+ 2.486	32
18.	Jaime Alguersuari	Toro Rosso Ferrari	+ 2.653	37
19.	Heikki Kovalainen	Lotus Cosworth	+ 3.330	37
20.	Lucas di Grassi	Virgin Racing Cosworth	+ 4.733	28
21.	Jarno Trulli	Lotus Cosworth	+ 4.801	11
22.	Timo Glock	Virgin Racing Cosworth	+ 5.032	29
23.	Bruno Senna	HRT Cosworth	+ 5.140	35
24.	Karun Chandhok	HRT Cosworth	+ 5.460	25