MONTREAL, Canada, June 5, 2008 (AFP) - Robert Kubica has challenged his BMW Sauber team to make the necessary improvements and deliver him a race-winning car.

Kubica has enjoyed an excellent season so far. Ahead of Sunday's Canadian Grand Prix he lies fourth in the world championship, just six points behind leader Lewis Hamilton.

But even with BMW Sauber now firmly established as the third quickest team behind Ferrari and Hamilton's McLaren, Kubica is aware that there are still huge strides to be made if the German-Swiss team are to achieve their target of a race win this season.

Speaking at a press conference in Montreal, the Pole said: "We are pushing and trying to do the best we can and maybe one day we can stay in front of Ferrari and McLaren."

"The car has to improve if we want to beat Ferrari and McLaren and achieve the target of winning a race this season. That is the target this season, but there is a long way to go."

"For now the only way to stay close to them is to be consistent and score points in every single race. That is what I am trying to do."

In the short-term Kubica knows that he will have to rely on a good slice of fortune if he is to challenge for race wins - the kind of good fortune that carried him to second place last time out in Monaco.

"Of course Monaco was a very good race," he continued. "The conditions were different than usual with quite a lot of water. I drove quite a good race with no mistakes. I think I did a good job there. In dry conditions though, we saw the car was not up to finish second."

Despite suffering a huge crash in Montreal last year, Kubica is looking forward to the weekend's racing. With more rain expected it could be another chance for BMW Sauber to chase that elusive first victory.

"Although last year, as everybody knows, I had quite a big accident, Canada is one of my favourite race tracks so I'm very happy to be here," Kubica added. "In 2006, when I was reserve driver here, I performed very well."

"This year the weather forecast says it might rain, or it could be similar to Monaco. We had a good race in Monaco, so I'm looking forward to a good race and good points here."