Fernando Alonso may provide Mercedes a bit of a challenge after the Ferrari driver claimed the fastest time in the second practice session for the Canadian Grand Prix on Friday.
The Spaniard, who nearly lost his Ferrari after he saved himself from ending up at the ‘Wall of Champions’, clocked a time of 1 minute 14.818 seconds at the Circuit Gilles Villenueve to snatch the top spot from Lewis Hamilton.
"We didn’t manage to complete our programme because the track was wet in the morning and so only tomorrow will we find out if the updates we tested here produce a real performance evolution," Alonso said.
"The only certainty is that we must ensure we make the right decisions, because today we saw how getting a clean lap depends a lot on the time you make the decision and what track conditions are like at that moment," he added.
Hamilton has admittedly suffered with issues with the brakes this season but he was just 0.012 seconds slower than Alonso’s time.
“The track is definitely not at its full potential yet but we were able to start analysing the tyres over longer runs and work on getting them up to speed for the first lap,” Hamilton said.
A few spots of rain fell with 15 minutes left on the clock, which allowed Alonso's time to hold up just when drivers usually post their quickest times.
It led to some slipping and sliding, including a near-crash between the Red Bull of Mark Webber and Lotus' Romain Grosjean.
Several drivers slid off the circuit, hit the kerbs hard or spun in the tricky track conditions even though it was a largely dry session in Montreal. Rains earlier in the day had met the track difficult to negotiate even after it had dried up.
Hamilton was one of the many who missed his braking point. The Mercedes driver missed the corner at Turn 8, opting to take the escape route to get back on to the circuit.
Behind Hamilton was Grosjean with the third quickest time followed by Webber, who spun at Turn 6, and Nico Rosberg.
Sixth was Felipe Massa, who like his teammate had a close call when the Brazilian appeared to have scraped the paint off the wall with his tyres during one of his runs.
Defending world champion Sebastian Vettel, seventh fastest, wasn’t impervious either. The German went off the track at Turn 1 before rejoining the circuit at Turn 2, trimming the grass along way.
"It was quite slippery, with low grip at the end. The dominating factor was the weather and we’re not sure what’s going to happen tomorrow,” Vettel said.
Adrian Sutil was eighth in the Force India followed by Jenson Button of McLaren and the Toro Rosso of Daniel Ricciardo rounding up the top ten.
Kimi Raikkonen was 11th ahead of Sergio Perez with the top 13 drivers separated by just over one second.
“We improved the car through the day and by the end of the session it was ok; not ideal but certainly not a disaster either," Raikkonen said. "If we can get the tyres working better it will be an improvement for sure, but it’s not going to change the world."
Pirelli had introduced prototype development tyres to be used for evaluation purposes but the weather conditions could only allow limited data to be collected.
"The new tyre compound was ok, it wasn’t expected to be hugely different, but it ran well," Webber said. "It would have been nice to do some more work on it, we got five laps – but it’s better than nothing."