Last year's Canadian Grand Prix was characterised by rain, and this year, the threat of rain strongly influenced how the drivers used their tyres during free practice.

As of this year, the drivers can use their full allocation of 11 sets of slick tyres from the very beginning of the weekend. With clouds looming over Montreal, the teams took the opportunity to run on both the P Zero Yellow soft and P Zero Red supersoft tyre from the first free practice session this morning, in order to be sure of accumulating enough data even if it rained in the afternoon.

With conditions remaining dry but menacing as the second free practice got underway in the afternoon, in ambient temperatures of 22 degrees centigrade, the teams started longer runs on the supersoft right from the beginning. This was in order to gain more data on the supersoft tyre using heavy fuel loads: something that the teams were lacking after the rain-affected practice sessions in Monaco two weeks ago.

With just over half an hour to go, the second session was red-flagged after Williams driver Bruno Senna hit the wall. This caused a delay of 14 minutes, interrupting many of the long runs that some teams were undertaking. The first session in the morning was also affected by a red flag for 13 minutes in response to a similar accident for Caterham's Heikki Kovalainen, underlining the difficulty of the Circuit Gilles Villeneuve.

McLaren driver Lewis Hamilton was fastest in both sessions, with a best time of 1m15.259s in the afternoon set on the P Zero Red supersoft tyre. He was fractionally ahead of Ferrari's Fernando Alonso, who used the same to set his time at the end of his forth run.

The fastest time established on the P Zero Yellow soft tyre was fourth-quickest, 0.272s slower than Hamilton, from Red Bull's Sebastian Vettel. Mercedes driver Michael Schumacher also set his quickest time on the soft tyre in seventh. The top 10 were covered by just 0.619s in the second session, emphasising once more the closeness of the competition this year.

Hamilton was also quickest in the morning session thanks to a time of 1m15.564s that he set on the soft tyre with 20 minutes to go, beating Vettel - who was on the supersoft tyre - by just over a tenth of a second. Hamilton also beat the fastest time in the equivalent first free practice session last year, set by Mercedes driver Nico Rosberg.

Paul Hembery: "The teams were disadvantaged by wet weather during free practice in Monacoa fortnight ago, and we think they were all quite rightly wary of this happening again. So we saw plenty of drivers on the soft and supersoft tyres right from the beginning of the first session, but without knowing which fuel loads the different cars were running, it's quite hard to get a firm idea of their relative pace. Our initial findings suggest that there may be a difference of around 0.4-07 seconds between the two compounds, but as the circuit is evolving all the time, we will only be sure once we have analysed all the data. The fact that there was a red flag in both sessions simply goes to underline the difficulty of this circuit, with grip at a premium. Had the second session gone on for just a few minutes longer, we would also have seen the Cinturato intermediate and wet tyres coming out, so it emphasises just how unpredictable this race is. Under the circumstances, the teams will want to accumulate as much information as possible to cater for every eventuality. I am sure we will see plenty more running tomorrow morning as the teams continue to collect data and with the top 10 covered by just 0.619s we are surely set to see a very close qualifying session."

Sets used overall:

Supersoft: 24
Soft: 48

Highest number of laps per compound:

Supersoft: 463
Soft: 974

Longest runs per compound:

Supersoft: 21 (Grosjean, Hamilton, Raikkonen)
Soft: 19 (Senna)

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