Ferrari set to keep F-duct for Monza

The unique nature of Monza means there is theoretically little benefit to be had from stalling the rear wing - either through the straight-line speed advantage it brings or the extra downforce it allows you to run.

However, with the title fight so finely poised, teams may make their final decision about the F-duct after Friday practice in Monza - when they will have a better idea about its benefits and disadvantages.

Ferrari team principal Stefano Domenicali has said though that his outfit was likely to keep it on its car for its home race.

"I have to say that at the moment the F-duct will stay on the car for Monza," he said when asked by AUTOSPORT.

McLaren had previously been set to remove the system from its car for the first time this season, but it is now expected to run back-to-back tests with and without it at Monza just to check that taking it away does not hinder its performance.

Team principal Martin Whitmarsh said that his outfit would only go public with its plans when it arrived at the Italian Grand Prix.

"We have made our decision," he said. "We've got our plan and we know what we are doing - which will be seen when we get there."

Renault, whose F-duct helped deliver a big step forward in performance in Belgium last weekend, was also open-minded about its plans.

Renault team principal Eric Boullier told AUTOSPORT: "I don't know the latest from [tech chief] James Allison, and I will check when we are back, but I am not sure we will have it for Monza.

"It is due to the fact that you develop a special aero package for Monza, and it is a big challenge to fit the F-duct on this. I am not sure, if you look at the ratio of drag/downforce, that it is a big gain."