"I think tomorrow or the next couple of days we might have a better understanding of where we stand with that". "I think the team have done a great job throughout the weekend", said Hamilton.
Vettel, who now has a one point lead in the Formula One title race over Hamilton, said: "For us, qualifying started a bit slow; obviously with the conditions it was a little bit tricky". "You can see how close it is between us all".
The Mercedes pair is poised for another one-two victory it achieved after starting from the front row in Barcelona last month. "It's really, really great to have this result, and a one-two".
"It's going to be a little harder to focus on the race because we will be watching it", he told reporters on Thursday. They are like, 'Oh, you can't say that.' But [it's a case of] 'No, I thought we said we're in that comfort zone, you can say what you want.' Naturally, everyone is shedding their blood, sweat and tears to make sure we win this season.
Hamilton's Mercedes team-mate Finn Valtteri Bottas, who was second in opening practice, suffered a water leak in the afternoon and wound up seventh after he was unable to complete the second session. "We have a good auto".
Vettel rued the mistakes that left him on the second row, but he feels Ferrari has a strong vehicle again this weekend as he bids for a fourth victory of the season after previous triumphs in Australia, Bahrain and Canada, and he will be starting on the Ultrasoft Pirelli on Sunday as opposed to the Supersoft that Hamilton, Bottas and the two Aston Martin Red Bull Racing drivers will utilise.
That opened the door for the impressive Charles Leclerc to secure a career-best eighth on the grid behind Carlos Sainz, with Kevin Magnussen's final lap hurt by Raikkonen late in Q3 and Grosjean not setting a time.
The pole, in a time of one minute 30.029 seconds, was his third of the year and pushed his Formula One record to 75. Hamilton said on his team radio the McLaren driver was going "dangerously slow" when he came upon him.
Brendon Hartley will start the race from last place after Toro Rosso had to change his Honda engine on Friday.
The return of the French GP after a decade-long absence is the first part of an unprecedented tripleheader of three races on consecutive weekends with the Austria and British events coming in quick succession.
The last time a F1 race was at Le Castellet was in 1990, when French great Alain Prost won for Ferrari.