"We know that we know nothing," laughed Mercedes' competition director, according to SID news agency.

Some rain on the usually clear and blue Cote d'Azur clouded the picture even further, but there appears plenty of competitive cars.

Ferrari and McLaren topped the two practice sessions respectively, but also fast were Lotus, Williams and Sauber.

Struggling was Red Bull.

"We couldn't try the changes that we wanted to make, because of the weather," the team's Dr Helmut Marko said.

"This is bad for us because we are not where we want to be, and we urgently needed this time."