Over the years a new 911 Cabriolet has consistently made its debut around six months behind the Coupe. This time Porsche surprised us by exhibiting the Cabriolet version at the driving launch of the Coupe back in January, and the ink had barely dried on our Coupe stories when the invitation to the Cabriolet launch arrived.
With the Cabriolet press launch in March for an on sale date of May for Europe and September for the US, Porsche are clearly keen to capitalise on the momentum of their best 911 Carrera ever.
The standard Turbo width bodywork that gives the Coupe its visual muscle works just as well on the Cabriolet models. Here the big wheel arches filled with 20-inch wheels in front and 21-inch wheels at the rear provide a visual platform for the sleek soft top whose profile is very close to the Coupe’s in silhouette.
Its effectiveness in cutting through the air is borne out by its 0.3 drag coefficient, which is only marginally worse than the Coupe’s 0.29. All else being equal this slight degradation is the result of a floorpan reinforcement member compromising part of the flat underbody.
The front of both models is identical as are the doors. The new exterior sheet metal begins aft of this where the wheel arches now blend upwards into a neatly styled rear deck profile that helps the Cabriolet look good whether its soft-top is up or down.
At the extreme rear, the active rear spoiler is the same, but on the Cabriolet the control programming adopts the three-position algorithm normally reserved for cars with the Sport Chrono Package. In this case the third position is used when the roof is down since the airflow is then quite different.
The industry norm for body-in-white torsional stiffness comparison has always been a static measure. This is gleaned by placing the bodyshell on a jig that applies twisting forces at defined points to elicit a defining figure in terms of Nm/degree.
However, this static test does not realistically show how a bodyshell reacts to loads fed to the shell via the suspension hard-points when the car is cornering or negotiating bumps on real roads.
So while the new MMB platform that both the 992 Coupe and Cabriolet are built on enjoys a 10% greater static torsional stiffness than its predecessor, Porsche proudly pointed out that its dynamic torsional stiffness also shows a 10% improvement.
This was the first time dynamic torsional stiffness has ever been discussed at a press launch event, and the engineers also told us that this stiffer shell allows them to offer the Sport suspension option on the Cabriolet for the very first time. This features a 10mm lower ride height with uprated springs and anti-roll bars.
As on the Coupe, the ride and handling is aided by the latest PASM system, featuring Bilstein active damping whose valves react fast enough to alter their resistance in mid-stroke. Previously a damper had to wait for its piston to reach the top or bottom of its travel before altering its resistance, so the new system takes damper control technology to a whole new level, providing improved comfort at one end of the spectrum and improved handling at the other.
The other thing that makes a difference to the driving dynamics of both Coupe and Cabriolet versions is the more forward location of the engine mounts that helps to reduce the polar moment of inertia at the rear both in cornering and over bumps.
With its frame made from steel, aluminium and magnesium components the new canvas folding top, its mechanism, and the structural reinforcement to the body-in-white extracts a 70kg (154 lb) weight penalty over the Coupe. It can cycle up or down in a swift 12 seconds, and operated on the fly at up to 50km/h (30mph).
The rear wind deflector is also a new design, and operates in about two seconds. With the side glass in place this deflector helps to provide a remarkably draft-free al fresco driving experience.
When it is place the triple layer fabric roof insulates the cabin from the elements very effectively, and unless you glance over your shoulder you could just as well be in the Coupe.
From the driving seat the view forward is identical to the Coupe apart from the switches that operate the roof and rear wind deflector. Thus the instrument pack with the big rev counter remains the analogue centrepiece, and is all that remains visible when you switch off the ignition and the electronically generated readouts on either side go dark.
The 10.9-inch widescreen display is intuitive to use, and the quality feel and precision of the five shortcut switches positioned under the screen is pleasing in use. The screen displays the image from the reversing camera that is standard on the Cabriolet.
Another plus is the big, clear “M” for Manual button behind the small transmission lever that locks the transmission in the ratio you choose with the paddle shifter. This is important as the PDK gearbox software will otherwise automatically shift up or down even in Sport Plus mode.
Another technical improvement in the cabin is an upgrade to the optional Burmester High-end audio system. Apart from revised DSP algorithms the system benefits from the dashtop centre channel speaker now being the same AMT (Air Motion Transformer) tweeter unit as used on each side. The advantages over the previous cone speaker are manifest in the improved imaging and transparency of instruments and vocals.
The seats in our test car had fabric centre panels, which we prefer to leather because it is warmer in winter, cooler in summer, and holds you better in cornering.
The 992 Carrera S Cabriolet and Coupe share the 9A2 Evo 2,981cc twin-turbo flat-six with its revised intercooler and intake arrangement. This develops 450hp at 6,500rpm and 530Nm (391 lb ft) of torque from 2,300 to 5,000rpm.
With the rev limiter set at 7,500rpm there is plenty of rev headroom when you need it, and the strong low-end punch coupled to a soaring, feral top end delivers the best of both worlds.
The healthy torque spread delivers impressive flexibility and the aggressive full throttle soundtrack with the exhaust in Sport mode is emphasised with the roof down.
The eight-speed PDK twin-clutch transmission is the perfect partner for this lusty turbocharged engine, delivering smooth and rapid ratio changes in both directions. Its closely stacked ratios provide a gear for every occasion, and where each ends the next instantly takes over to keep the snappy motor on the boil.
With the tall eighth ratio making for relatively relaxed highway cruising - 120km/h (75mph) corresponding to around 1,600rpm for instance - a tank of fuel goes even further than before.
However, this depends on how you drive. We noticed that economy was good if we left the gearbox to its own devices, and that consumption rose steeply when we used the ‘M’ button and paddle shifts on entertaining stretches of twisty roads.
As top speed is achieved in sixth gear, the tall seventh and eight gears effectively give you two over-drive ratios. A manual gearbox will be offered from September as the entry-level transmission.
Despite being larger and around 50kg heavier than its predecessor the 992 Cabriolet is significantly more rapid. The Sport Chrono Package equipped Carrera S Cabriolet now takes just 3.9 sec (991.2 - 4.3 sec) to cover the 0-100km/h sprint, (3.7 sec 0-60mph (991.2 4.1 sec), while 200km/h (124mph) is reached in 12.8 sec (13.6 sec. Top speed is marginally up at 306km/h (190mph) (304km/h, 189mph).
The bi-turbo flat six is sonorous with the exhaust in Sport mode, and makes for an engaging drive with the roof tucked away under the smooth rear deck. Better still if you can find a tunnel. We had to make do with some rock faces in the hills but they provided enough amplified echo to put a big grin on our faces.
The improved structural stiffness is apparent from the comparative lack of scuttle shake on bumpy roads, and the new 992 Cabriolet dives for apexes and jumps out of corners with even more confidence than before. Unlike some mid-engine rivals its limit handling is more linear and predictable and less upset by having the top down.
Because the suspension geometry now stays closer to optimum under load the gains in handling and ride are real, and the dreaded scuttle shake, the bane of all open cars, is also kept in check.
If you really push the car hard through the bends as we did on the coastal test route in Greece it becomes obvious that the Cabriolet is not as rock solid and incisive as the Coupe, which is the better choice if you want to do track days.
That said, as with all convertibles, you can still feel an increase in rigidity on a bumpy road with the roof up, and the handling does benefit from this when you are really pressing on.
The 992 Carrera S Cabriolet is a versatile and practical 2+2 you can use all year round. And should you live in a place where the roads are slippery in winter the Carrera 4S Cabriolet is the perfect solution.