The strength of the BMW M4 Coupé is evident in every detail.
By: IOL Motoring Staff
Geneva Motor Show - One of the advantages of a mid-engined sports car made by a Formula One constructor is that the Spider version doesn't carry an automatic weight penalty, as do most other drop-top models.
That's because an F1 car doesn't have a roof.
The carbon-fibre Monocell on which all McLaren road cars are built was designed on the same principles as its Grand Prix tubs and, like them, doesn't rely on its top deck for structural integrity.
OK, the McLaren 650S Spider, making its world debut this week at the Geneva motor show, is actually 40kg heavier than the Coupé (1370 versus 1330kg), because it has a complex folding hard-top and tonneau system with its attendant electric motors, but a roadster model with a manually-operated soft top would actually be lighter than the coupé.
And here's the kicker:
The 650S Spider has exactly the same performance, handling and torsional rigidity as the coupé. The same 480kW/678Nm, 3.8-litre M838T twin turbo V8 launches it from 0 - 100km/h in the same breathtaking three seconds flat, and to 200 in 8.6 seconds, just two ten tenths behind the hard-top (and that, we suspect, is due to the coupé's better aerodynamics). Top speed is quoted at 329km/h, fuel consumption at the same 11.7 litres per 100km.
But - and this is a very big but - the Spider's two-piece roof folds neatly away in less than 17 seconds away at up to 30km/h and, as with the 12C Spider, the 650S Spider has a heated glass rear window that's independent of the roof.
With the top down, it acts as a wind deflector, reducing cabin buffeting and, with the top up it can be lowered to allow more engine noise - and driving drama - into the cabin, and for cabriolet-style driving even in the rain.
But the 650S is not a stripped out racer-for-the-road.
Coupé or Spider, its comes with carbon-ceramic brakes behind special '650' lightweight alloy rims wearing Pirelli P Zero Corsa tyres. The cockpit is fully trimmed in alcantara synthetic suede and IRIS satellite navigation with Bluetooth telephony, digital radio, audio streaming and voice control are all standard.