MONTREAL, Canada -- Mercedes boss Toto Wolff says the team is yet to find the "holy grail" with set-up to perfectly utilise Pirelli's softest tyre, despite beating Ferrari to pole in Canada.
A scintillating Lewis Hamilton lap put Mercedes back in front of its title rival on Sunday's grid, reversing Ferrari's strong pace from practice. Mercedes arrived in Canada having struggled to extract performance from the ultra-soft tyre in Monaco -- a tyre being used again this weekend -- where both drivers finished off the podium and Ferrari recorded a one-two finish.
Hamilton's gap of 0.330s to Vettel was helped by Mercedes tweaking its strategy around tyre preparation during qualifying. Though Mercedes has extensively looked into what caused the Monte Carlo issues, Wolff thinks it is wrong to assume the team has solved its problems with one strong qualifying showing.
"I don't think we have discovered the holy grail, but the more data we collect, the more we learn and the better we will put the jigsaw together," he said. "But it is still a complicated picture. You can see the differences between the two cars with no real major discrepancies in set up, still very different performances and when you listen to the drivers, there is difference in how they perceived the car."
When asked if he was confident the problems of Monaco had been solved, Wolff replied: "It was a pretty optimum sequence of races because looking at last year's Montreal performance, it was clear that this would be another difficult race for us.
"With our confidence last year we had just a tenth's advantage in qualifying last year, so all the guys stuck their heads together and there's been lots of analysis that has been carried out from our diligent analysts and that helps with learning. We put the car on track, it was different to what we would have done without having the setback in Monaco. So therefore there is a result, a learning curve in relation to set up and its effect on the tyres."
After hinting that Mercedes took steps to ensure its one-lap pace was strong in Montreal, Wolff said that placed a question-mark over the team's set-up for the race.
"I don't think there is a fear but there is always the risk and sometimes we are in unknown territory. It's not like the last couple of years, 2012, 2013, were you could effectively compromise your race performance a lot by being very aggressive with the set-ups for qualifying. We haven't done that.
"I think it's more dependent on the track temperatures, the air temperatures, being in traffic or not in traffic, which can have such a massive effect on the grip on the tyres. That is the difference. It's a bit random and we are trying to fill those random spots with data and try to understand it."