After revealing its all-new Cayenne last month, Porsche then unveiled the current top-of-the-range Turbo at this year’s Frankfurt motor show. Now with a three-strong model range, including the basic Cayenne, the S and the Turbo, Porsche invited evo to learn everything there is to know about the new SUV. We were also treated to a passenger ride around the ADAC’s test facility near Düsseldorf.
There are currently only three engines available in the Cayenne, however all are direct injection turbocharged petrol with ‘hot-V’, which is where the compressors are located on top of the engine between the cylinder banks. The base Cayenne is powered by a 3-litre V6 that produces 335bhp and 332lb ft. Oddly, the more powerful Cayenne S has a smaller capacity V6, only a 2.9-litre. Still, it betters the 3-litre unit by 99bhp and 74lb ft to give it a total power out put of 434bhp and 406lb ft of torque. The added power is thanks to an extra turbo nestled between the two banks of cylinders to make it a twin-turbo. It also uses variable valve timing on the inlet cam.
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The motor that powers the Cayenne Turbo has two extra cylinders and a capacity of 4-litres to help it produce its 542bhp and 568lb ft. The V8 in the Turbo is part of the same modular family of engines – the six-cylinder unit being a shortened version of the eight.
As well as the packaging benefits, one of the aspects utilised by a ‘hot-V’ configuration on a V8 engine is easily being able to feed two turbos with both banks of cylinders. That keeps the turbos spinning consistently despite the irregular nature of a cross-plane crank V8’s firing order. Porsche hasn’t done this, though. Instead the Turbo’s V8 uses two twin-scroll turbochargers with each chamber fed by two cylinders from the same bank to try and even out the turbine speeds.
At least one diesel engine for the Cayenne is imminent. Porsche hasn’t confirmed which oil burner might find their way into the front of the big SUV but, as the SUV’s petrol engines are shared with current Panamera, the saloon’s 4-litre twin-turbo V8 is the most likely candidate. The diesel V8 in the Panamera is also the same engine found in the Audi SQ7, only without the supplementary electric driven turbo. Whether the Cayenne will get the Audi’s third compressor, Porsche wouldn’t confirm.
Chassis and drivetrain
Like Porsche’s other models there is a selection of options to choose from should you wish to improve the way the Cayenne drives. It can be specced with Porsche Dynamic Chassis Control (PDCC), which consists of front and rear anti-roll bars that each have an electric motor and gear set. The motor is used to counteract the twist of the bar and, effectively, make it stiffer when necessary. The system can also almost completely decoupled to improve axle articulation when off road.
There are also two different types of Porsche Active Suspension Management (PASM), one with adaptive dampers and coil springs and another with three-camber air springs and adaptive dampers. The latter system allows the car to continuously vary the spring rate by using a combination of the three air bags. As spotier driving modes are selected different combinations of the three air bags are used to create a spring rate ideal for whatever the situation. However, rather than change the balance of the car, the spring rates increase by the same amount front and rear to maintain some consistency in the way the Cayenne drives.
The air suspension also allows the ride height to change, too; it can raise the body to increase its ability off road and lower it when above 99mph to help reduce lift.
Both the PASM air suspension and PDDC anti-roll bars are standard on the Cayenne Turbo, but are a £2606 and £2315 options respectively on the rest of the range.
One of the most contentious parts of the new Cayenne is its mix of tyre widths front to rear, with the wider set being on the rear axle. That means, proportionally, that the front axle has less mechanical grip than the rear – or, as the Porsche engineers were quick to point out, that the rear has more grip thanks to even wider tyres than before.
But rather than Porsche wanting to introduce more understeer into the Cayenne’s balance, the wider rear-tyres are intended to counteract the new car’s fast steering ratio. The rear needed to be more stable because of the more alert and direct front end that comes with the Cayenne’s 13.3:1 fast ‘rack. To give that figure some context, the steering ratio of other SUVs using the same front platform as the Cayenne use a 15.8:1 ratio.
Four-wheel steering is standard on the Cayenne Turbo and a £1448 option on other versions. It helps high-speed stability even further, allowing engineers to deliver an even faster 12.2:1 steering ratio.
Any agility lost by the narrow front tyres is regained by a torque vectoring electronically-controlled limited slip differential standard on all models.
As well as providing more stability in a corner, the wide back tyres also hint at the way the Cayenne distributes its power. A variable centre differential favours the rear axle, only sending a small proportion of torque to the front. Sport and Sport Plus driving modes accentuate this, only sending drive to the front wheels when really necessary. As a result, mechanical grip at the rear is essential.
Considering that Porsche developed a whole new 8-speed dual-clutch – or in Porsche terminology, PDK – for the new Panamera, you’d expect the mechanically similar Cayenne to use the same gearbox. But, no. The Cayenne is equipped with a conventional automatic gearbox with a torque converter.
The reason for this is mostly because Porsche wanted the Cayenne to be capable of towing 3.5tonnes, and the more robust automatic was better suited to that task. A torque converter is also better at slow-speed high-torque crawling that’s often needed when navigating tricky off-road environments. The variable centre diff and torque vectoring e-diff at the rear are also capable of locking completely to improve the car’s offroad ability.
The basic Cayenne and S come with cast iron discs with six-pot calipers as standard, but there are two other brake options: Porsche Carbon Ceramic Brakes (PCCB), a familiar carbon-ceramic set-up and new coated cast iron discs called Porsche Surface Coated Brake (PSCB) with 10-piston calipers. A hot, high-pressure gun fires a tungsten and carbon compound onto the braking surface of a regular cast iron brake disc. This gives it a 100-micron thick tungsten carbide surface that, once finished, leaves a mirror-like finish. These new brakes come as standard on the Cayenne Turbo, or as a £2105 option on the other models.
The coating on the discs makes the surface much harder than regular uncoated cast iron, and it therefore allows a more consistent braking force even as the brakes get hot. Porsche’s tests have shown that PSCB brakes behave similarly to carbon ceramic brakes when used to stop repeatedly. However, PCCB is still much lighter – saving around 24kg of rotating unspring mass on the Cayenne over the cast iron set ups.
The harder surface also increases the lifetime of the discs by 30 per cent and, if driven carefully, the pads too. When driven hard the pads wear at a similar rate to those used on conventional brakes; the discs still withstand wear better no matter how the car is driven.
Another benefit of PSCB is that the coated discs and appropriate pads produce 90 per cent less brake dust. That’s why Porsche has chosen white calipers to denote the new brakes, while yellow calipers still denote the PCCB set-up.
Although currently only available on the Cayenne, PSCB will find its way onto the whole of the Porsche range soon.
Rather than being a purely Porsche creation the Cayenne uses some of the basic architecture from other cars in the VW family. The front and middle structural platforms are borrowed from the Audi Q7, however, because of a different wheelbase the rear is bespoke to the Cayenne.
One of Porsche’s goals with its new SUV was to make the body lighter than its predecessor, as well as being stronger. The engineers managed to reduce the body-in-white’s mass by 22kg, which was achieved by using more aluminium. Now around 47 percent of the Cayenne’s body is aluminium including the doors, boot and bonnet. Underneath large and expensive cast aluminium parts are used to support suspension components. Don’t envisage bulky, rough castings though, these parts are covered in intricate and neat strengthening webbing – if they weren’t so functional they’d be pieces of art.
Having steel and aluminium together isn’t wise when trying to prevent corrosion as the two materials react badly when placed together. Everywhere that steel is joined with aluminium in the Cayenne the two are bonded together with glue, not only to create a secure connection but also to provide a barrier to stop the two materials touching.
Such a variation of materials in the Cayenne’s body creates a problem when it’s heated up in the paint section of the production line. With aluminium and steel expanding at different rates, without very careful planning, the body could distort beyond recognition and not shrink back to its proper shape once it had cooled. So that there’s room in the body to swell when it’s taken up to 80 degrees Celsius in the paint shop, some creases are added to the car’s shape. The lines that stretch the length of the roof are not for style or aerodynamic purposes, they are there purely to allow the body to expand and contract safely.
Like a modern sports car, the Cayenne Turbo has adaptive aero devices that move to either reduce drag or help reduce lift. Unlike the spoiler on the trailing edge of the Cayenne and Cayenne S’s roof, the one on the Turbo doesn’t have a flick. Instead it follows the line of the roof to minimise drag as much as possible. However, above 99mph or if Sport mode is selected, the rear edge of the Turbo’s spoiler raises by 20mm. Then, when either the separate spoiler button is selected or the car is put into Sport Plus mode, it raises to 40mm. The higher the spoiler the more effective it is at reducing lift, but that also causes drag. So, once over 124mph the spoiler totally retracts to make the body as smooth as possible.
There are a further two positions the wing can take, if the car is also equipped with an opening panoramic roof the back of the spoiler raises to 60mm when the roof is opened to compensate for a wind deflector. The final position happens under braking where the spoiler raises to 80mm to create as much drag as possible and slow the Turbo down. It can reach its maximum angle in just 0.9sec and helps reduce the car’s braking distance by 2metres when stopping from 155mph.
As well as the spoiler moving, flaps behind the front grilles also open and close. Whenever it’s possible, horizontal flaps in front of the central radiators and vertical ones in front of the intercoolers close to help reduce drag. The car then decides when to open them taking into account the temperature of the engine, how hard the car is being driven, how much power is needed and whether the air conditioning is being used. The central and side flaps can move independently of one another, depending which part of the car needs to be cooled.
The new Cayenne uses the same infotainment system as the new Panamera, which means a touch panel around the gear selector, a large 12.3-inch central screen and twin screens within the instrument cluster. But because the Cayenne is slightly newer, there are a few improvements over the saloon’s system. ‘Points of Interest’ now have reviews, while parking listings will inform you whether there are spaces available and how much it costs to park.
It’s the same situation with the driver assistance systems, too. While, just like the Panamera, the SUV has adaptive cruise control and comprehensive park assist functions. What’s new on the Cayenne is a wheel rim protection system that alerts the driver to any obstacle that could cause and damage to the wheels or tyres.
An update that will come sometime next year will also allow drivers to see their car from outside in a 3D environment on the main screen to help them park. Images from the cameras on the Cayenne are projected into a virtual bowl, while objects and topography detected by the radar and parking sensors also appear within the virtual landscape. The driver can then select a view point from anywhere outside the car so they can then navigate around items that wouldn’t be seen from inside, or might be missed by plain 2D cameras.
From the passenger seat
Fast SUVs are no longer a novelty, really. The Cayenne Turbo’s performance, although impressive on paper, is no longer remarkable to witness. Still, the level of refinement and comfort when travelling at speed of the new car was notably better.
What we’re not used to are huge SUVs with a playful and entertaining side, one that mimics characteristics usually the preserve of wild super saloons or well-sorted hot hatchbacks. From the passenger seat, there was a palpable sense that a lot of the Cayenne Turbo’s grunt was being sent to the rear axle and there was some throttle adjustability even in fast corners on dry tarmac. This was then confirmed by some large oversteer on soaking wet tarmac; after turning into a corner at a very moderate speed, with a little bit of trail braking, the demonstrator was able to apply lots of throttle in second gear and the Cayenne drifted sideways. The four-wheel drive obviously intervened, as there was no need to add any corrective lock, but it didn’t try to curtail the slide only stopped it from becoming too excessive. The demonstration may have been staged in a very controlled environment but it displayed a very un-SUV like intent for the new Cayenne Turbo.