Don't expect Porsche to shout about the new Cayenne Turbo S E-Hybrid Coupe being its heaviest production car yet. With batteries and an electric motor added to the Turbo S's 4.0-litre V8, the range-topping Cayenne tips the scales at a colossal 2,535kg, making it 130kg heavier than a Range Rover Sport HST and 338kg more than the Lamborghini Urus. It also has 680hp from its electrified powertrain, with 664lb ft of twist on tap from not much more than tick over, making it comfortably more potent, too. But there's no beating around the bush: if there's a Porsche to affect tidal forces, this is it.
As you might expect, much of the running gear is shared with the Panamera Turbo S E-Hybrid (which is 200kg lighter, by the way) promising the same all-electric capability and near instantaneous torque delivery, albeit with a roofline that's 250mm closer to the ground. Like that car, the hybridised Cayenne Coupe has been designed to offer the most persuasive mix of high performance and efficiency in its class, and on paper it certainly promises a more explosive reaction to your right foot than Land Rover's HST, while retaining the zero-emission mode that distinguishes it from super SUVs like the Urus.
Consider: 62mph comes in 3.8 seconds, 0-124mph takes 13.3 seconds with just 85g/km CO2 to show for it. Nothing else in the segment comes close. And despite its mass, Porsche is resolute in designating the Coupe an ultra-high-performance driver's car. Its three-chamber air suspension is claimed to be more than up to the job of managing its extra hardware - and those auxiliaries deliver the 19 miles of pure electric range which ostensibly make the car more attractive to city dwellers.
That this Cayenne starts in Hybrid mode by default is evidence enough of its objectives. As with the Panamera, there's no raucous V8 exhaust note to greet you here. There's an E mode too, in which you'll need to squeeze the throttle past an artificial stop in the accelerator pedal (think of a kick down button that's located at half throttle) to awaken the twin-turbo unit. But even in the default setting you're getting a silent Cayenne that primarily leans on its 136hp and 295lb ft synchronous motor, which will gently whisk you to 84mph if you request it. Refrain from pinning the throttle and electric progress remains good enough to keep up with traffic and it's satisfying enough to pilot such a large, purposeful machine in this way.
But, let's be honest, nobody buys a 680hp 'Coupe' to leave it in electric mode on derestricted Autobahn (yep, we're in Germany). Sport mode fires the V8 into life with so little hesitation that you wonder if it was running silently in the background all along. There's no mistaking its voice, with whine immediately traded for a deep throated rumble (that's particularly aggressive with the £2,000 Sports exhaust equipped) and an accompanying shove up the backside. Unleash it and the Turbo S E-Hybrid gets up and goes from pretty much any starting point on the speedo, the motor's unabated heft emphasised by electric torque fill and the swiftness of PDK shifts. It rides nicely, too, particularly if you go into the menus and switch the air suspension back to its softest mode - though it can't get to the levels of waft delivered by a Range Rover HST. But the trade-off for that is a chassis that feels completely settled, even at very high speeds, so sitting in the outside lane here feels almost mandatory.
Exchange three lanes for the countryside, and the composure doesn't degrade. The standard fit anti-roll system doesn't seem quite as forthright as it does in the Bentley Bentayga (a touch more pliancy perhaps left in to placate the giant kerbweight) but there's still the unmistakable feel of the air suspension tensing up once the body pitches more than a couple of degrees. Predictably, it means you can really charge along a route, assured that the mechanical grip on offer is far beyond anything you could (read: should) challenge on a public road; a set of enormous (440mm front and 410m rear) standard-fit carbon ceramic brakes standing up to hard work with ten and four-piston calipers respectively, behind 21-inch wheels. The hybrid energy recovery tech adds to the engine braking, but largely it feels like those carbon rotors are just supremely resilient to heat.
Much of the Coupe's all-wheel steering system has been taken from the 992, and there's certainly a similar level of natural agility added into the equation, even from the elevated platform of the Cayenne. It's obviously appropriate that such a large car would have a small amount of safety understeer when really pressing on, but it can so easily be overcome with the throttle that you probably wouldn't ever want a dartier nose. For such an enormously heavy machine, the predictability and accessibility of its corner-exit rotation is something to behold. In the same way a Macan can sometimes feel like a hot hatch, this Cayenne seems like a much smaller performance SUV.
A standout powertrain feature is the boost button in the centre of the wheel-mounted rotary dial that primes the engine for an overtake by dropping a couple of cogs (assuming you start from a cruise) and readying the hybrid system for instant response. Inspired by the 918, it means you can pick small gaps to overtake like you were in a supercar. Conversely, if we're searching for a negative from the hybrid setup, it's that the varying kinetic energy recovery can leave the brake pedal feeling quite vague unless you're really on it; slowing the car smoothly requires more adjustment from your foot than normal, so it takes some getting used to - although after a few hundred miles it would probably become second nature.
On balance, then, the most tech-filled Cayenne Coupe has a lot going for it - and that sentiment goes double for the cabin, which mixes low-slung, excellent sports seats and carbon fibre trim and an Alcantara-wrapped steering wheel about as well as any car you'd care to imagine. That's almost a given for Porsche these days, but in contrast to something like the similarly pricey Maserati Levante Trofeo (£124,900 to the Porsche's £125,946), it certainly reinforces the idea that the E-Hybrid is no one-trick six-figure pony.
That said, it doesn't excuse it from comparison with its own stablemates. If you're after weight-defying super-SUV performance with a muscular V8 soundtrack, the regular Turbo offers most of the hybrid's appealing traits at more than £20k less. Much like the Panamera, the Turbo S E-Hybrid only makes genuine sense if you prize its capacity for pure electric running - and in this day and age, 19 miles looks like fairly feeble recompense for the outlay. For some (if not most) of the Cayenne's customers though, that last qualifier is unlikely to be an overriding concern, and there's no doubt that the model's myriad attributes have been expertly juggled to appeal to their city-based requirements. For everyone else, Porsche's heftiest model is yet another reminder that a vast quantity of electrically-assisted torque is still the industry's go-to - and not unlikeable - solution to a weight problem.
SPECIFICATION - PORSCHE CAYENNE COUPE TURBO S E-HYBRID
Engine: 3,996cc, V8 twin-turbo, plus electric motor
Transmission: 8-speed Tiptronic S, all-wheel drive
Power (hp): 680@5,750-6,000rpm
Torque (lb ft): 664@1,500-5,000rpm
0-62mph: 3.8 seconds
Top speed: 183mph
MPG: 52.3 - 58.9