New Porsche Cayenne Turbo S E-Hybrid prototype review

The Porsche Cayenne SUV was not short of performance before, but the new Turbo S E-Hybrid slingshots it into the reaches of supercars. Intoxicating? Yes. Necessary? Not entirely. For this money, bragging rights really do matter and the Turbo S E-Hybrid delivers the numbers, but you can’t help but avoid that this really isn’t the Cayenne package at its most rounded or sweetest.

Say hello to the most powerful SUV to ever wear the Porsche badge: the 671bhp, 900Nm, two and a half tonne Cayenne Turbo S E-Hybrid. It pushes Porsche’s second biggest seller into an entirely new performance envelope, giving it the punch to compete directly with the Lamborghini Urus. 

Key to providing that Lamborghini taming power is the exact same engine as you’ll find in the Italian brand’s super-SUV. At the heart of this new Porsche is a turbocharged 4.0-litre V8 engine producing 542bhp, but it receives the same electrified assistance and additional grunt as the Panamera Turbo S E-Hybrid. That means an electric motor developing 134bhp joins up with the petrol motor, and while they don’t develop peak power quite at the same time as each other, the resulting 671bhp is very close indeed.

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The electric motor resides between the engine and gearbox and is fed by a 14.1kWh battery. Porsche claims that if you keep the cell topped up (a full recharge takes 2.4 hours via the on-board 7.2kW charger), the car is good for almost 25 miles on electric power only. Top speed in the E-Power electric mode, which is the default drive mode selected on start up, is 84mph. It means that the Cayenne Turbo S E-Hybrid can cruise emissions free on the  motorway, but this is far from the quietest car capable of all-electric running due to wind and road noise, and that 25 mile claimed range will disappear far faster than that.

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That said, the test route provided for our taste of a pre-production Cayenne Turbo S E-Hybrid said a lot about where Porsche believes this astonishingly powerful people mover will perform to its full potential. Germany’s autobahns, and in particular the derestricted sections, are where this Stuttgart-born leviathan really makes the most sense. 

Around town the powertrain’s electric element is a brilliant fall-back and will mean congestion charge exemption in the Capital when it arrives in Britain in October. But this huge, heavy car, straining at the leash to make the most of its enormous power reserves. 

Few drivers will have the confidence to throw this massive car hard into corners on twisty roads. Even though it wears a Porsche badge, nothing can be done to hide the sheer mass. The Cayenne Turbo S E-Hybrid tips the scales at 2,490kg unladen of any passengers, with the Coupe heavier still at 2,535kg. Forget any notions of poise, it’s a blunt instrument and unapologetically so.

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This hybrid Cayenne is intended for tallying up mile after mile, in straight lines and at some speed. Switch into Sport Plus, floor the accelerator, and the pace builds at the same monumental level regardless of gear or revs, and barely beginning to lose its battle with physics once above 150mph - you can thank the engine for that, as the electric assistance quickly becomes obsolete. The gearbox is an eight-speed torque converter, largely lacking the crispness or immediacy of Porsche’s PDK transmission, but precision really isn’t the Cayenne Turbo S E-Hybrid’s brief.

It builds speed with startling consistency and swagger - and a nice exhaust note - but not without fuss. Road and wind noise are pretty intrusive, and though three-chamber air suspension is standard - as is Porsche Active Suspension Management with adaptive dampers and the 48-volt assisted anti-roll system used on the Bentley Bentayga - the physics at play are impossible to overcome.

With so much pace meeting so much power, the Cayenne Turbo S E-Hybrid is far from a fine riding SUV. The Cayenne has never been a car to sacrifice its genuine abilities for comfort, but while lesser, lighter members of the line-up exhibit far more in the way of dynamic involvement and pliancy, perhaps this 671bhp hybrid is a lesson in overkill. Both of those key elements take a severe hit, the trade-offs and main selling points being two curious opposites: the ability to run the car on electric power only, and raucous straight line, V8 soundtracked performance if you so desire. 

Like nearly all plug-in hybrid machines the integration of the battery takes its toll on practicality. The 14.1kWh battery is integrated under the rear bench, reducing the boot size from 745 litres to 645 in the case of the more conventionally shaped car, and down to 500 litres in the newer Coupe, which commands a £2,500 premium. 

The cabin itself is still an immense environment, and quality is every bit the Cayenne Turbo S E-Hybrid’s £120,000 plus price tag should command. The driving position is as fantastic as you’d expect too, but while the touchscreen infotainment is a slick setup, the centre console remains awash with somewhat user unfriendly touch sensitive switchgear. It’s nice to look at, but a pain to use on the move.