Renault boss says Kubica a huge asset

The French car manufacturer has taken a podium finish and leads the chasing pack on to the top four quickest teams - Red Bull, Ferrari, McLaren and Mercedes.

Kubica also finished in fourth place in last weekend's Malaysian Grand Prix and is just nine points behind championship leader Felipe Massa.

Boullier thinks that Kubica's commitment and demanding nature have helped spur his staff on.

"Robert Kubica is very, very eager to do well and is very, very committed to the team - and that is a big asset that is difficult to evaluate," Boullier told AUTOSPORT.

"What I have seen every day since the beginning of testing and even before is Robert every time really sticking to the engineers.

"He is very, very demanding - and the good thing is that when a driver is very demanding and then does some good races like he has done in the first three races with no mistakes and very good pace, then the team is really respectful of what he is doing - and the team delivers more."

Boullier, who believes his outfit is almost as quick as Mercedes GP, adds that the strong chemistry between Kubica and his team is driving the team on much quicker than he expected.

"With the team fitting with Robert, and Robert fitting with the team, we just build up something more successful," he said.

"The team is pushing, the driver is demanding and gets the results - one feeds the other. I expect the team to be much stronger."