RAPID REACTION: Mercedes show off new W12 car – but what are they hiding, and why?

Can the reigning champions make it an eighth constructors' championship win in 2021? Mercedes revealed their new car, the W12, on Tuesday morning – though the team admitted there were plenty of details they weren't quite ready to show off yet. Here's F1 technical expert Mark Hughes' instant take on what we saw, and what we didn't see, on the car expected to be the class of the field in 2021...

Within the constraints of the requirement to retain the same basic chassis as last year, Mercedes appear to have attacked the task of clawing back the downforce lost to the new floor regulations with particular relish on the new W12.

FIRST LOOK: Mercedes retain black livery as they unveil Hamilton and Bottas’ new F1 car for 2021

Technical director James Allison was making no secret of the fact that the floor edges of the car displayed at the launch were not those of the pukka '21 car and that there is some detail apparent there which they wish to conceal from the eyes of the opposition for as long as possible.

Looking at how shrunken they have made the engine cover and sidepods and how extremely contoured they are, it would appear that the aerodynamicists have tried extremely hard to work the whole sidepod and floor edge shape in a way that claws back as much of the downforce taken away by the trimming of the floor’s dimensions.

READ MORE: Mercedes tech chief cagey over where team have spent development tokens on 2021 car

Aft of the radiator inlets, the sidepods drop down dramatically both laterally and horizontally. Together with whatever they may have done with the so-far concealed floor edges, the aim is probably to induce some sort of Coanda effect – whereby the flow clings harder to the sweep of the bodywork sides and therefore is fed with extra force to the gap between the rear wheel and diffuser wall – which is such a crucial part in maximising the effectiveness of the underfloor in creating downforce.

At the launch, Allison said the “sexy bulge” (above) atop the sidepod was “hiding some of the work that our friends at HPP have done to squeeze more horses into that power unit for us for the year”, but it could well be a reflection of how much the bodywork has been shrunk rather than signifying an enlarged mechanical component beneath.

The bargeboards have been extensively refashioned for a flow aligning with the new sidepods.

READ MORE: 'We can talk if we want to do more' says Hamilton as explains why he only signed a one-year contract

At the front of the car the nose and general layout appear much as before, with a slight tweak to the front brake duct shape, which will all be part of the same re-alignment of flow as the bargeboards.

Together with claimed significant gains in the power unit, the W12 appears to be a nicely aggressive reaction to the limitations in place in this final season before the all-new regulations.

Our next glimpse of the car is likely to be at Bahrain pre-season testing in mid-March, when it should be in something closer to its race spec, with those secretive aerodynamic parts Allison mentioned likely to feature.