The era of fuel-guzzling monster cars are coming to an end, thanks to the ever-tightening emission regulations. Knowing that, Porsche couldn’t possibly let the Lamborghini Urus and Aston Martin DBX have the whole super-SUV pie just to themselves.

As a last hurrah for the pure internal combustion engines, Porsche is now developing an all-out “ultimate” Cayenne featuring a tweaked twin-turbocharged 4.0-litre V8 petrol engine. And according to Auto Express, who were given the privilege to test drive the prototype, it’ll supposedly make 640 hp and 850 Nm.

Compared to the Cayenne Turbo that’s currently on sale, the new top-of-the-line Cayenne makes an additional 98 hp and 80 Nm of torque, shaving off around 0.5 seconds in its 0-100 km/h sprint time and raising the top speed to 300 km/h.

While the Cayenne Turbo S E-Hybrid technically still makes more power, Auto Express says that the weight penalty from its fancy hybrid system means that it “can’t keep up” with the new ultra-performance model when it comes to acceleration and top speed.

Aside from the significantly more powerful engine, Porsche’s own press release also says that it’ll come with a new Porsche Dynamic Chassis Control (PDCC) active roll stabilisation system, which helps “keep the body balanced and level even during very spirited cornering” – at least according to Porsche’s own test driver, Lars Kern.

The new “ultimate” Cayenne also rides on 22-inch forged aluminium wheels, shod with 285 and 315 section tyres front and rear – the largest tyre Porsche has ever fitted as standard on the Cayenne. The larger offset on the wheels marginally increases the track on both ends, while also allowing for more negative camber – 0.45 degrees to be exact – which increases the contact area between the tyres and the road.

Further dynamic upgrades come in the form of a 15% stiffer air suspension, which also doubles as an aesthetic tweak to give the new super-SUV an aggressive stance on the road.

Porsche says that the all-new “ultimate” Cayenne is currently undergoing final testing and optimisation in the hands of Lars Kern and two-time World Rally Champion, Walter Röhrl who had the following to say: “The car remains incredibly stable even in fast corners, and its turn-in behaviour is extremely precise. More than ever, you have the feeling that you are sitting in a compact sports car rather than in a large SUV.”

As such, most of its visual changes are still largely hidden under the black camouflage. We do know that it’ll only be available in the Cayenne Coupe form though, and will come equipped with a new titanium exhaust system with the dual exits positioned centrally on the rear bumper.

Also, if you haven’t noticed yet, we’ve been calling it the “ultimate” Cayenne in quotation marks for now, because Porsche has yet to give the super-SUV a name. If we had to guess, it’ll probably be called the Cayenne Turbo S, as it’s the one “traditional” Porsche name that’s absent from the current model line-up – just don’t quote us on that.