 Montoya will be heading to McLaren at the end of the year |
Juan Pablo Montoya admits the current Ferrari is "incredible" and has called for a major improvement from Williams. The Colombian has had just two podium finishes this season, while Michael Schumacher has won all four races.
"This year the team set up quite high goals and we are miles away," said Montoya.
"At the moment we have nothing new and radical coming in terms of development. We are improving - but the Ferrari just looks incredible."
Montoya, who will move to McLaren at the end of the year, added: "It is frustrating in some ways and not frustrating in others.
 | I don't know where I am going to be next year  |
"It is frustrating for the wins but the team is still doing a good job and we are still up there taking podiums. The Williams team has not been helped by the continuing rivarly between Montoya and team-mate Ralf Schumacher.
The German believes Montoya should stop complaining and concentrate on driving.
Montoya branded Ralf's older brother and reigning world champion Michael "blind or stupid" after they collided at the San Marino Grand Prix.
"Juan seems to complain a lot about other people instead of looking after his own driving style," said Ralf.
"To try and overtake someone on the outside - he should know that doesn't work, when you are half a car behind."
Meanwhile, Schumacher has hinted he may well quit Williams after talks over a new contract ground to a halt. The German has been linked with Toyota after failing to hammer out a new deal with Williams.
"One thing is certain, I will be in Formula One," he said ahead of the Spanish Grand Prix. "I just don't know where I am going to be next year.
"It is basically in my hands to decide what I want but we still have to wait."