Ferrari driver Fernando Alonso says it is difficult to predict which of the sport's top five teams will have an advantage in 2013.
When asked whether Ferrari can win this weekend's Australian Grand Prix, the Spaniard admitted that no-one knows what will happen.
"I think difficult to know. No-one knows who can win this race at this moment. We have to wait and see for answers to some questions that winter testing doesn't answer," he said.
"I think there are top teams with a little bit of advantage. Maybe it's not the same as last year where we saw seven different winners in the seven first races. It was a little bit mixed on the grid."
"I think this year with the consistency in the rules I expect the five top teams to have a little advantage and not to have many, many surprises in the first races. But from these five top teams I think it's very difficult to see really after winter testing who has this extra two- or three-tenths that can make you win. At the moment I think it's very close and very difficult to choose one favourite."
Alonso added that any one of ten drivers could win this weekend in Melbourne.
"I think so. I think Mercedes, McLaren, Lotus, Ferrari and Red Bull show up some potential in different days in testing and different parts of races last year. I think difficult to choose"
Alonso also believes that Ferrari must make a good start to a 'challenging' period of the championship.
"I think it will be a very interesting championship, very challenging first part of the championship with Australia, Malaysia. Difficult circuits, difficult weather as well – changeable. So we need to start on the right foot and hopefully scoring some good points for the championship."