The McLaren P1, revealed this evening, is set to become a yardstick by which all other hypercars are compared against – much in the same way as its predecessor, the F1, did in 1992.

As we reported last week, McLaren’s goal with the P1 is “ be the best driver’s car in the world on road and track.” Which will be no small accomplishment, given how strong the competition looks over the next 5 years.

The car revealed in Paris this evening (and earlier this week on the web) is described as a ‘design study’, so while it looks ready to roll, McLaren will display the production version of the P1 next year, before putting it on sale within the next 12 months.

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While we’ve pored over the images, what we really want to know is what makes the P1 a supercar? After all, the Bugatti Veyron grabs the headlines with its 1,100bhp engine, while the McLaren F1 was immortalised when it reached 243mph on Volkswagen’s Ehra-Lessien test track in Germany.

Huge levels of downforce at low speeds

One of the P1’s most distinguishing supercar features is its aerodynamics, specifically downforce, which reaches much higher levels than any current road car.   In fact, no less than 600kg of downforce is generated by the P1 well below maximum speed, which is approximately five times as much downforce as that produced by a McLaren 12C.   The McLaren P1’s downforce is similar to current sports racing cars such as the 12C GT3 racer, and yet the P1 is a road car.

Despite the huge performance, the McLaren P1 is also said to be a refined and comfortable high speed sports car. “It is designed to be driven to the racing circuit, with great levels of comfort and refinement,” says McLaren Automotive Managing Director, Antony Sheriff “..And then to be used on the racing circuit, where it will offer an experience matched only by purpose-built race cars.”

While McLaren do not expect the P1 to be the fastest in a straight line, it nevertheless is astoundingly quick. Power to weight ratio will be more than 591bhp per tonne, partly due to the increased power of its 3.8-litre twin-turbo V8 engine, but also because it has been built with extreme-lightness in mind.   In fact the McLaren P1 is defined by advances in weight reduction, packaging, high-speed performance, materials (especially carbon fibre), its hybrid powertrain and in its use of aerodynamics.

This goal – racing car-like track performance from a road car – was one of the primary targets for McLaren P1. The P1s frontal area is substantially less than the already compact 12C, and smaller than any other super-sports car in production.   McLaren quote a Coefficient of Drag (Cd) of 0.34 – which is extremely low considering the car’s enormous levels of downforce.

Active aerodynamics include Formula 1-like DRS

The former Head of Aerodynamics for McLaren Racing, and now Head of Vehicle Technology for McLaren Automotive, Simon Lacey, was responsible for the aero performance: ‘The astonishing downforce actually makes driving easier as well as faster,’ says Lacey. “As you go faster, you actually feel more in control.”

The large rear wing adjusts automatically to boost downforce and optimise aerodynamics. It can extend rearwards by up to 300mm on a racetrack, and by up to 120mm on the road, while the pitch of the rear wing can increase by up to 29 degrees.

The double element rear wing profile has been developed using exactly the same methods and software as the current McLaren Formula 1 car and is able to stall the airflow, just like the DRS (drag reduction system) in a modern F1 car – reducing downforce and increasing straight line speed.

In addition to the adjustable ‘active’ rear wing, the McLaren P1’s aerodynamic performance is optimised using two flaps mounted under the body ahead of the front wheels. These are also actively controlled, and change angle automatically to optimise performance, boosting downforce and aero efficiency, increasing both speed and driver confidence. The flaps operate through a range of 0 to 60 degrees.

As suspected, the rear wing can also act as an airbrake when deployed, and works in tandem with the front flaps to boost handling, braking and straight line performance.   The real benefit from the P1’s active aerodynamics is not just in terms of lateral grip, it also ensures totally consistent handling and driving behaviour which McLaren claim will make the P1 easier to drive.

The smooth underbody of the P1 is also designed to boost downforce by generating a ‘ground effects’ suction force – another F1-sourced technology, first developed by Gordon Murray (designer of the McLaren F1) when Technical Director of Bernie Ecclestone’s Brabham team.

Use of exotic light-weight materials

Just like its predecessor, the McLaren P1 makes use of gold leaf heat shield around the exhausts. Gold is the ideal metal to reflect heat, regardless of cost and it’s this mindset that prevails throughout the P1’s design.

As with the legendary McLaren F1, the P1 is a mid-engine design that uses a carbon fibre monocoque and roof structure safety cage concept called MonoCage, which is a development of the MonoCell used in the current 12C and 12C Spider.   The structure of the MonoCage, unlike the 12C’s MonoCell, also serves to guide air into the engine through an integral roof snorkel and air intake ducts, saving further weight.

All the P1’s body panels are carbon fibre, which is another of McLaren’s core values – McLaren was the first team to offer a full carbon body Grand Prix car back in 1981 and became the first company to offer a full carbon body road car, in the F1.

There are also very few body panels. The McLaren P1 uses large clamshell single-moulded front and rear panels, which are attached to the central carbon MonoCage, and that’s it, apart from two small access flaps in the rear, a front bonnet and two doors. This reduces weight and the number of shut-lines, creating a cleaner, smoother appearance.

The large carbon panels, which are extraordinarily thin and light whilst also being very strong, are multi-functional, with integrated scoops and ducts used to boost aerodynamic performance and cooling.

Form follows function

Everything on the P1 is there for a reason – every duct and every surface does a job, either in aero or in cooling. Within such strict principles, Design Director Frank Stephenson worked closely with Chief Design Engineer, Dan Parry-Williams, to design a car that was “striking but also functional.”

Everything has been made as small, light and dynamic as possible. The carbon structure is exposed where possible, not only showing where the air is travelling but also to break up the visual mass of the body and make the car look light and agile.

‘I wanted it to look like a Le Mans racer with that low body, long rear deck and open mesh rear styling to put the mechanicals on view and to help cooling,’ says Stephenson. ‘Plus there is the most aggressive rear diffuser ever seen on a road car. Like everything on the McLaren P1, it’s there for a good reason.’

The glasshouse was inspired by the canopies of fighter jets, giving the occupants similar sensations to a pilot. The windscreen is deeper than it is wide, creating a feeling of lightness and airiness inside.

The lights are a signature part of the car. The LED headlights, with their speed marque DRL, are extremely small in size meaning more frontal area can be devoted to cooling. Whilst at the back, the low rear deck and pronounced wheel arches, give the evocatively simple rear end a powerful graphic.

Image: Lee McKenzie

The concept being that the rear lamps are literally the trailing edge of the bodywork, framing the diffuser and allowing more heat to exit from the engine bay. ‘Again, beautiful, organic forms framing and enhancing the technical features,’ says Stephenson.

The McLaren P1 made its debut at the Paris Motor Show today, however we’ll have to wait until early in 2013 before details of the P1’s powertrain and other technical information are revealed. Deliveries are expected to commence in late 2013, the year of McLaren’s 50th anniversary with prices somewhere in the region of £800,000.

Better get saving then.