Lewis Hamilton ended Friday practice in Montreal frustrated with both his McLaren's pace and the track conditions. Although McLaren had been fastest with Jenson Button in the morning, when Hamilton took third, in second practice the latter had fallen to seventh, while Button was down in 11th.
Hamilton reckoned the main issue was with the dirty track surface proving hard for the tyres, but also reckoned McLaren had problems to resolve with its set-up.
"I'm not happy with how this afternoon went -- I think today in general the track has just been incredibly difficult to drive," he told reporters. "It's very difficult to switch the tires on, to get heat into the tires, and it's just like being on an ice rink out there. It's so slippery.
"It's a huge difference to how it was when I was here before. We had great grip [back then], the track got better and better, but we were struggling [today] for sure. We're not pulling away down the straights, we have quite a lot of bottoming. There are areas we can improve on, we just have to do a big debrief now and figure out where we want to go with the car tomorrow. But it's a bit of an unknown, because we tried a few things and the car was just as bad, if not worse."
The Briton said the biggest struggle had been keeping the softer tires intact, with most of the field suffering with graining.
"On the option tire it's unbelievable," said Hamilton. "With the graining I had on the option tire, I had to come in. But I think a lot of people had the same experience, except perhaps the Red Bulls, so it's going to be an interesting one. I don't think you'll be seeing a long first stint on the option tire, that's for sure."