McLaren still wary of Ferrari threat

On the back of their dominant 1-2 finish in Monaco, McLaren duo Fernando Alonso and Lewis Hamilton have secured the front row of the grid in Montreal and again look to be a step ahead of Ferrari.

But Dennis is cautious in reading too much into Ferrari's difficulties in qualifying, where they were edged out by BMW Sauber's Nick Heidfeld, and believes that the situation is still unclear.

"You obviously monitor the performance of your closest competitors, but we don't really spend much time trying to analyse why they are a little quicker or slower," said Dennis.

"We know if we are slow then we have to make our car faster. We cannot rely on them standing still.

"This is a circuit that requires characteristics from a car. We obviously worked hard in Paul Ricard (testing), but I would not read too much into the situation at the moment. Maybe they feel the strategy is to go long and we will just have to see how the race unfolds.

"We have put a lot of effort into our braking systems. It is always a compromise here. You are compromising your braking system to get the longevity that you need, because it is the worst circuit of all as regards braking.

"We would like to feel positive about our performance, so maybe we have done a better job in that area but time will tell."

Dennis admitted, however, that his team did have to put some effort in to modify their rear wings in the wake of the tougher FIA rear wing tests.

"Obviously it has been again an even more severe regulatory process in respect of rear wings. It caused us some problems.

"We had to modify our wings to ensure absolute compliance. They were compliant, but we wanted to have a margin."