Lewis Hamilton says his Mercedes is "back to normal" at the Canadian Grand Prix, but admits it was still not quick enough to match Kimi Raikkonen's Ferrari in Friday practice.
At the last round in Monaco, Hamilton struggled for performance and qualified 13th before finishing the race seventh. At the root of his lack of pace were difficulties putting the tyres in the correct operating window, but in Friday practice in Montreal he was back on form and second fastest -- 0.215s off Raikkonen's best effort.
"The car feels back to normal, but it is still weak in a lot of areas," he said. "The Ferrari is still the quickest and with everything that I'm currently pushing with, I can't beat the Ferrari's time.
"A two tenths margin is quite a good margin in that session. We'll see if we can improve the car overnight, but it looks like it will be a tenth or within a tenth.
"It's exciting, but positioning is everything because between the four of us it's going to be very difficult to overtake on Sunday."
Technical director James Allison added that Mercedes' drivers are facing a tricky balancing getting the W08 to work at its best.
"We've got a car that has got many strong points but there is some trickiness to the way that it handles. That presents us with particular challenges when we are setting the thing up, but there is plenty we can do in the short-term, plenty we can do at each race and plenty we can do over the medium-term too.
"There has been a couple where Lewis had a tougher time. What he feels is a lack of grip in the car and what we see, and what we talk about afterwards, is that the grip is there but it's ever so easy to overstep it and pay quite a heavy penalty in lap time as a consequence.
"That experience that Lewis has had on a couple of occasions, Valtteri has had as well in a different direction in a different track. We have a situation where we have a car with a lot of performance that is able to compete in the front, but the window in which that performance is available is quite narrow and easy to step out of."