McLaren got off to a strong start at Monza on Friday morning, despite testing a rear wing that looked more suited to a high-downforce track.

While many rivals were running more conventional for Monza 'tea-tray'-style wings for the Autodromo's long straights, observers were surprised when the MP4-25 emerged from the pits with a very big rear wing.

After the British team hinted it might not use an F-duct at all this weekend, the wing was indeed used on Friday morning in conjunction with the downforce-shedding innovation.

The implication is that McLaren achieves high straight-line speeds by activating the F-duct on the straights and stalling the wing, while in the corners the car gains a competitive advantage by producing higher-than-normal downforce.

Jenson Button topped the morning timesheets at the Italian circuit, while his teammate Lewis Hamilton was third quickest in the sister car.

McLaren strong at Monza with big rear wing