Bridgestone's super soft tyre took Red Bull Racing's Sebastian Vettel to the fastest time of the day amidst difficult track conditions at the Circuit Gilles Villeneuve in Montreal.

Vettel set a 1m 16.877secs time in the afternoon session on a day of changeable weather. Reigning world champion Jenson Button (Vodafone McLaren Mercedes) was fastest in the morning, using the medium compound Bridgestone Potenza.

Q&A with Hirohide Hamashima - Bridgestone Director of Motorsport Tyre Development

What was significant about today's running?
"The dirty track surface here and the cooler than usual temperatures meant that graining was today's talking point. The tyres were not able to work to their full potential due to not reaching their best operating temperature. This meant the tyres were sliding, causing transverse graining on front tyres from braking and transverse graining on the rears from traction demands. We expect that the track surface will continue to improve with more rubber laid, and the graining will diminish. Weather forecasts also predict warmer temperatures which will be beneficial too. However, there is rain included in these forecasts so there is potential for this to be a very interesting weekend in terms of maximising tyre performance potential."

How do you expect this allocation to work over the weekend?
"More than any time so far this season, this is a very difficult question. The Circuit Gilles Villeneuve is always a difficult circuit to understand, even when weather conditions are favourable. We certainly would expect better performance from both compounds as the track surface gets more rubber laid on it and as the weather improves, but how the compounds will react relative to each other is a difficult question. Teams and drivers will have to work very hard this weekend."

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Stats of the Day:
Practice One 10:00 - 11:30: 
Driver 		   Team			Time 	    Tyre 
Jenson Button      Vodafone McLaren	1m 18.127s  M
Michael Schumacher Mercedes GP F1 Team  1m 18.285s  M
Lewis Hamilton     Vodafone McLaren	1m 18.352s  M 

Practice Two 14:00 - 15:30
Driver 		   Team			Time 	    Tyre
Sebastian Vettel   Red Bull Racing 	1m 16.877s  SS
Fernando Alonso    Scuderia Ferrari	1m 16.963s  SS
Nico Rosberg 	   Mercedes GP F1 Team 	1m 17.151s  M

Compounds used: Hard / Soft

Temperatures 	 Ambient      Track 	   Weather
AM - Practice 1  18C-19C-17C  20C-24C-19C  Cloudy / Sunny
PM - Practice 2  20C-21C      24C-26C      Cloudy / Partly Cloudy