The secret here is simple. The global Grand Tourer market, by McLaren's reckoning, is twice the size of the supercar segment, and expanding. McLaren wants to expand, too - and doesn't want to build SUVs. Hence the GT, Woking's inimitable take on what a GT could be if you opted to build it around a modified supercar tub, with a supercar body and a decidedly super 620hp 4.0-litre twin-turbocharged V8.
The angle is a compelling one, and McLaren freely admits that it has been heading in the direction for some time. The 570 GT clearly taught it a lot; not only about how you might go about doing such a car, but also that the market for it already exists among its patrons. That it has been asked about providing more space for luggage, and a more relaxing long-distance driving environment, is not a surprise; McLaren's decision to spin out an additional model family from the concept is.
The Grand Tourer will sit alongside the Sports, Super and Ultimate Series, and can therefore safely claim to fulfil a somewhat different set of parameters. Naturally, outstanding ride comfort and cabin refinement are among them. As is a previously unseen boast in McLaren's context: the GT offers a total stowage capacity of 570 litres, and the ability to load it with skis. Or golf clubs.
If that idea puts a shudder through you, then rest assured that it has not been achieved with an un-McLaren like sacrifice of ideals. 'Lighter, faster and more engaging' is the pleasing GT mantra. According to its maker, the new model is 130kg lighter than its closest core competitor. And according to the DIN figure (plus 90 per cent fuel) it's only 32kg heavier than a 570 GT - which is remarkable thought when you actually see the car because it seems substantially larger than its spiritual forbear.
That impression is a consequence of the GT's greater length - based on the 720S, it's fully 153mm longer than the Sports Series model - alongside a new design that certainly accentuates it. The latter was intended to absorb established Grand Tourer styling cues, while retaining a recognisable 'McLaren' aesthetic. In this it largely succeeds; the front and rear overhangs extend out further than elsewhere in the range, making the proportions less immediately pleasing - but a simpler, more elegant looking model has duly emerged.
The rear-end is likely to earn the most plaudits, which is appropriate given that's where much of the engineering effort is focused. The front-hinged, full-length glazed tailgate is substantial and reveals a relatively shallow but impressively long luggage compartment. McLaren claims 420 litres for the beautifully upholstered expanse, some of it liberated via a repositioning of the GT's exhaust (relative to other models in the lineup).
The real hero though is the new MonoCell II-T carbon fibre monocoque (T for Touring) which incorporates an additional upper structure to permit the creation of the larger void alongside those glazed C-pillars and the rear-quarter windows. It makes for a slightly airier cabin, too; handy when you're advocating the space for longer journeys. To that end, the GT gets unique seats as standard, optimised to meet the standard required for 'long-distance comfort'.
You'll still have to negotiate a sizeable sill to access them, but the electrically adjustable and heated variation on McLaren's familiar streamlined design do seem very accommodating - based on PH's thirty-second go in them, at least. Elsewhere the interior is a recognisable migration of the brand's current architecture (maybe a little too recognisable, given the difference implied by the badging) albeit with some uber high-end touches like the option of an electrochromic glazed panel in lieu of the standard gloss black composite roof and cashmere trim (for the first time in a production car).
Amongst it all, McLaren promises the installation of its 'most sophisticated' infotainment system to date. Woking's limitations in this regard are long-established, and while it doesn't like to admit to them, the introduction of 'industry-standard' HERE navigation mapping and real-time traffic information in the GT suggests it is finally taking the problem seriously.
When it comes to the engine and chassis, McLaren needs no additional encouragement to get things right. The firm has never built an uncomfortable car - in fact, it has striven to do the opposite and peerlessly succeeded - yet here it promises to outdo itself with a bespoke Proactive Damping Control system intended to deliver 'remarkable' levels of comfort.
It will accomplish this using the same aluminium, double wishbone and hydraulic damper arrangement that features elsewhere, but will deploy a new iteration of the Optimal Control Theory software algorithm (yay science) to 'read' the road ahead and react accordingly. Or, to put it another way, expect the GT's 'Comfort' mode to be very compliant indeed - even with the introduction of 21-inch alloy wheels at the back, the largest ever fitted to a McLaren.
Powering those wheels is yet another variation of the 4.0-litre V8, the M840TE. Here the manufacturer promises two things: that it is bespoke to the GT and uses unique engine mounts designed to minimise structure-borne noise; and that it will make 95 per cent of its 465lb ft of torque available from between 3,000 and 7,250rpm. That speaks to the kind of drivability that McLaren is seeking, and likely points to the rivals it has benchmarked the GT against (the Bentley Continental GT, lest we forget, boasts 664lb ft from 1,350rpm).
McLaren will be mindful of such cars, obviously - Crewe's way of doing things is plainly held in high esteem in Surrey - but its own Grand Tourer claims to occupy space that no 2.2-tonne Bentley could ever reach. 'Sport' and 'Track' fill out the driver modes, and the engineers have retained the acclaimed single-map hydraulic steering that features across the board and promise to deliver the 'driving exhilaration expected of a McLaren'.
Mike Flewitt, CEO, said: "The new GT combines competition levels of performance with continent-crossing capability, wrapped in a beautiful body and true to McLaren's ethos of designing superlight cars with a clear weight advantage over rivals. Designed for distance, it provides the comfort and space expected of a Grand Tourer, but with a level of agility never experienced before in this segment. In short, this is a car the redefines the notion of a Grand Tourer in a way that only a McLaren could."
To that end, the GT is said to hit 62mph in 3.2 seconds and should be capable of 203mph, making it only slightly slower than a 600 LT. If that sounds like your cup of tea - and frankly the idea of a more liveable, practical and better refined McLaren is as close to milk and two sugars as the industry gets at the moment - the car is available to order now from £163,000. Expect delivery before the end of the year.