Lotus defends Kimi Raikkonen's performances

Raikkonen has faced particular difficulties in finding a power steering set-up that he likes - and that prompted questions about his attitude when he elected not to run in first practice in Monaco because he did not like the feel from the car.

With his inexperienced team-mate Romain Grosjean on a high after his strong second place in Canada, and now just two points behind Raikkonen in the drivers' championship, there is a renewed debate about whether or not the former world champion can rediscover his previous race-winning form.

But Boullier says the outfit is fully behind Raikkonen, and thinks it was only normal to expect the Finn to take time to fully get himself back up to speed in F1 - and for Lotus to understand how best to work with him.

"It is all part of the understanding between team and driver," Boullier told AUTOSPORT. "We had two new drivers in the team and each driver has his own driving style and characteristics.

"It is just part of the learning process - and teams like McLaren, Red Bull Racing and Ferrari, they have driver line-ups that they are used to working with.

"This year we had two new drivers - which included one nearly complete rookie. And with Kimi, we just had to take time to adjust. It has just been part of the process to understand his driving style and make adjustments to know how best to work together."

Lotus is still chasing its first victory of the year, and success for either Raikkonen or Grosjean in Valencia would make them the eighth different winner so far this season.

Although the team has been in with a shout of victory several times this season - including in Bahrain, Spain and Canada - Boullier says there is no mounting desperation to reach that target.

"There is certainly no frustration," he said. "I think we have to be proud of what we achieved so far, and I can only praise the efforts of factory and all the guys. There is no frustration to have - it is a new cycle, new drivers, and we knew we cannot have the perfect style from race one. You always have to improve yourself.

"Our car was coming from a little bit further back than the others, so it took time to get the package working. But it is nice to have some good expectations."