Heidfeld says Ferrari still ahead

The Italian squad have won the last three races - including a couple of one-two finishes - to move into the lead of both championships.

Their form, and their record at the Istanbul circuit, where they have won for the past two years, suggests Ferrari are favourites for victory again this weekend.

And Heidfeld believes the Maranello team will again be one step ahead of BMW and McLaren.

"We don't have a lot of new parts on the car - some minor adjustments that could suit this downforce level and personally, I think we will see something similar to the first couple of races," Heidfeld told reporters in Istanbul.

"Ferrari ahead and then McLaren and BMW Sauber fighting against each other."

The German feels there is little between BMW and their rivals McLaren, and he thinks the advantage will change from one track to the other.

"Only in the first race were they stronger. After that it was pretty equal - sometimes we had the upper hand, sometimes they did," he added.

Heidfeld is also hopeful BMW will be stronger at the Monaco Grand Prix in two weeks' time.

"I know Robert (Kubica) thinks our car is particularly strong on low-speed tracks. I hope it's true and it would be nice for Monaco. But otherwise I don't see a reason why we should win more in Monaco than anywhere else.

"Of course, more can happen - more crashes - but I don't think we can now say we'll win in Monaco because of strategy. There is no magic strategy; you can always gamble a bit though."