Gary Anderson BBC F1 technical analyst

"The most obvious novelty on the Sauber is the nose section.

"Unlike McLaren and Ferrari, they've kept the ramp nearly all cars had last year where the bodywork transitions from the lower height demanded of the nose cone and the higher height required of the chassis, but have fitted ridges on either side.

This will be a way of trying to prevent the air going up there from spilling over the sides into the leading edge of the sidepods, which is always the case with a flat top to the car.

"That air takes up space that would be better occupied by air coming off the front wing and barge boards. It will be a very small thing - but small things all add up.

"The sidepods do look narrower - the turning vane at the front corners appear further away than normal.

"If they are narrower, that is effectively reducing the cross-sectional area of the car and means more air goes around to the rear.

"At the back, I'm surprised they've abandoned their exhaust treatment in favour of the McLaren-style approach.

"This area is a compromise between the downforce created by the exhaust gases on-throttle and the general, always-there downforce from the coke-bottle shape at the back.

"The balance between the two is difficult to get right."