Robert Kubica says it is difficult to predict how Renault will perform in the Brazilian Grand Prix, with the Pole insisting that the prospect of rain at Interlagos could turn the race into a lottery.

Kubica scored his best result of the 2009 season at the Sao Paulo circuit with a second place for BMW Sauber and has been one of the stars of 2010 having switched to Renault over the winter.

Currently seventh in the championship standings - and just two points ahead of Nico Rosberg - Kubica will hope to strengthen his position in the title race this weekend although he admits that Interlagos isn't a circuit where it is easy to predict performance ahead of the event.

"Brazil is a bit of a strange track and it's really difficult to predict how we will perform," he said. "There is a long straight out of the last corner where the f-duct will give us lots of gain and this is also where the power of the engine will be important.

"I think that we might have a lottery with the weather because Brazil gets unsettled conditions at this time of year, so it's likely we will have some wet running, as we did in 2009. When it rains the track has very poor grip and you have to be lucky to get the perfect balance with the car."

Team-mate Vitaly Petrov crashed out in Korea in dramatic fashion after destroying his car in the barriers at the final corner and having also crashed out early on in Japan, the Russian said he was keen to pick up a good result to put those memories to bed.

"When you have tough races like Japan and Korea, you can't wait to get back in the car to forget those bad memories, so I'm really looking forward to Interlagos," he said. "But it's difficult to know what to expect because I've never been to Brazil before and it's another new challenge for me. It's a famous circuit because there have been so many great races there, especially in the last few years with the championship being decided. I remember watching these races on television so it will be great to experience it for real."