Jenson Button says drivers will have to look after rear supersoft tyres in Canada
Magnussen expects temperature increase to cause overheating
By James Galloway in Montreal. Last Updated: 07/06/14 12:08am
Jenson Button believes drivers will have to tread carefully with the supersoft tyres in Sunday's Canadian GP after the McLaren driver experienced graining within a handful of laps in practice.
Pirelli have brought the two fastest tyres in their range, the soft and the supersoft, to this weekend's Montreal event and drivers put the latter to the test during Friday's afternoon session amid increasing track temperatures on both high and low fuel.
Button, who finished ninth on the P2 timesheet, said graining on the rear of his MP4-29 had certainly proved noticeable when he pushed to the limit.
"I hammered it on the high fuel for a few laps to see what would happen," the Briton told reporters.
Jenson Button - Supersoft tyre stint
Lap 1 - Out lap
Lap 2 - 1:20.605
Lap 3 - 1:20.722
Lap 4 - 1:21.198
Lap 5 - 1:22.999
Lap 6 - 1:24.357
"We thought there might be graining and there was, so it's a tyre you definitely have to look after the rear more than the front. So I had a lot of rear graining and I only did five laps. But it's useful information to understand where we've got to put the car and how we need to drive."
Pirelli reported at the end of Friday's running that their two compounds had shown "limited wear and very little degradation" with the supersoft experiencing a "very small amount of graining". The Italian manufacturer is therefore expecting drivers to complete one or two pitstops during the race.
Although air temperatures belatedly climbed into the low 20s by the closing stages of Friday after a gloomy morning in Montreal, conditions are expected to get hotter by several degrees for both qualifying and race day.
Button's team-mate Kevin Magnussen said an increase in the mercury might prove problematic for McLaren given the team's car has a narrow tyre-temperature operating window, but they wouldn't be alone.
"If it gets hotter over the weekend overheating will be a problem, especially on the option tyre," he said. "But I think it will be the same for everybody."
Although the chasing pack behind Mercedes looked more tightly-bunched on Friday, Magnussen, driving for the first time at the challenging Circuit Gilles Villeneuve, said McLaren were targeting the head of the midfield.
"This weekend we are fighting to be on the top of the middle pack. So if we can be in front of the Force Indias and the Williams' then I think we should be satisfied," he declared after finishing P2 fractionally ahead of Button in eighth.
On a day of numerous off-course moments around the low-grip lap, the rookie was involved in one of the more dramatic-looking moments when Sauber's Adrian Sutil took to the final chicane run-off area as Magnussen slowed ahead of a hot lap.
Stewards looked into the incident only to find no wrongdoing on Magnussen's part and the Dane expressed surprise that Sutil had decided to jump across the kerbs.
"I don't know why he would choose to go on the kerb on the exit," he said. "There is an opening at the end.... maybe he didn't walk the track, I don't know. There is an opening at the end but I'm sorry to get in the way."