Mercedes-Benz G-Class vs Porsche Cayenne

What's the difference?

As per the 1979 original, the current G-Class is produced by Magna Steyr in Arnie’s home town of Graz in Austria. And many fundamental things haven’t changed since then. But clearly this EV monster’s exotic electric powertrain is a huge departure.

It retains impressive off-road ability and straight-line speed. But will it hit the mark with top-end luxury 4WDers? Short story, this thing is wild, and it will be irresistible for a likely narrow band of tech-focused ‘must have the latest and greatest’ buyers. Nothing like impressing friends and family with a tank turn.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

Of all the super SUVs I've piloted, the Porsche Cayenne Turbo GT is the best all-rounder in terms of performance, comfort, cabin technology and style.

As a family car it's roomy, practical and easy to use and drive daily.

As a performance car the Turbo GT is stupidly quick, with the agility of a sports car. Sure, a 911 would leave it behind on a twisty race track, but this SUV is close to having that sportscar experience and keeping your family, as well.

Okay, so Mercedes-Benz says, with a straight face, that “with the aim of optimising the vehicle’s aerodynamics” classic G-Class elements have been revised, including the reprofiled bonnet, ‘air curtain’ vents in the flares over the rear wheel arches, A-pillar cladding and the small spoiler on the edge of the roof.

At the same time, the 20-inch wheels are also claimed to be "aerodynamically optimised” and underneath, a 26mm underbody casing made from a mix of materials, including carbon-fibre (attached to the ladder frame with more than 50 steel screws), protects the battery from dust, dirt and rocks.

In ticking off the Edition One, car-spotters should look for black rims with blue brake callipers behind them, blue inserts in the exterior protective strips as well as black door handles and a new rectangular design box on the rear door for storing items such as charging cables, tools or snow chains. If you want a spare wheel, choose the standard model.

An optional black-panel radiator grille ($3800) features tinted lighting units as well as an animated LED light band and chrome surround. The light band can be activated as a running light or an animation when locking and unlocking the vehicle.

And it’s worth noting Mercedes-Benz and the car’s contracted manufacturer, Magna Steyr, have invested much time and many Euros in retaining the car’s classic handle and door lock design. G-Wagen owners will recognise its sound from several kilometres away.

Inside the G580 it’s clear this is one area where the G-Class has progressed enormously over the decades. It’s still quite upright in terms of the dash design, but you’re confronted by twin 12.3-inch screens, supporting the Mercedes-Benz user interface. 

All very high-tech, but that’s balanced by an old-school grab-handle for the front passenger to latch onto during off-road work. 

The signature turbine-style air vents are located within squared-off panels, and in the limited Edition One you have a blue fleck running through carbon-fibre inserts on the centre console, door cards and that front grab handle. In the standard car it’s a (very attractive) walnut open-pore wood rather than carbon.

A luxurious interior for sure.

This might be a personal thing but to me nearly all Porsches look better from the back than the front.

It's the wide stance and powerful haunches, the hunkered down suction-capped-to-the-road look that does it for me and the Cayenne Turbo GT, despite being an SUV, passes this important Porsche checklist item.

The GT aero kit only serves to make this SUV look more of a beast, and the gold-bronze looking satin Neodyne wheels are a Porsche theme that I've not always been a fan of, but I get the historic connection.

If only the Turbo GT could look a little less like other Cayennes from the front. This is the king of the SUV range and despite the apron and bumper already being exclusive to this model, there should be more.

Vents in the wheel arches, carbon bonnet with nostrils GT3-style perhaps? Or is that going too far? If you do want something more lairy then there's always the Urus.

The Cayenne Turbo GT's cabin is stunning in its plushness and modern surprises such as the passenger display, the hoodless instrument digital cluster, the lashings of Race-Tex upholstery everywhere. It's perfectly Porsche. High-performance meets high-end.

It's also highly practical. Let's talk about that.

For the record, the G63 is just over 4.6m long and a little more than 1.9m wide with a 2890mm wheelbase. So, not huge, but its close to 2.0m height is hard to ignore. 

In the front there’s lots of breathing space, and in terms of storage you have generous bins in the doors with plenty of room for big bottles. Then there’s a centre armrest, which doubles as the top of a deep storage box housing a USB-C port inside. 

A sliding roller cover in the centre console reveals two cupholders, another two USB-C sockets, a 12-volt outlet and a wireless charging pad. Add in a big glove box and you’ve got plenty of options in terms of storage, power and connectivity. 

In the back, sitting behind the driver’s seat set for my 183cm position I’ve got tons of foot and legroom and, no surprise, lots of headroom.

There’s a fair bit of sculpting in the rear seat, which is as nice as it is unusual (makers often avoid bolsters on the rear seat as it makes the backrest harder to fold flat). And in terms of three-abreast accommodation, a smaller adult will be okay in the centre spot for shorter journeys. Three up to mid-teenage kids will be swimming in it.

Then, for practicality you again have generous bins in the doors. And if you need even more capacity, fold down the centre armrest which houses two different size cupholders. 

In the rear of the centre console you’ve got two USB-Cs, a 12-volt power outlet, individual climate control and directional vents.

There are map rockets on the front seatbacks and more air vents in the B-pillar. So, when it comes to comfort, powering up devices and storing ‘things’ you’re well taken care of.

The side-opening tailgate door opens from right to left, which isn’t ideal when parallel parked on the left hand side of the road, but boot volume is over 600 litres (VDA) with all seats upright, expanding to nearly 2000 litres with the 60/40 split-folding rear seat lowered.

There are multiple tie-down hooks, a netted pocket, two lights, a 12-volt outlet as well as a ‘ski-port’ door and sliding cargo cover to enhance practicality and security.

As mentioned earlier, the full-size spare in the standard model, but the Design Box replaces it on the Edition One, although Mercedes-Benz says it’s aiming to make a spare available as an option later in the year.

The Porsche Cayenne Turbo GT only makes one compromise on practicality and that's the removal of the middle seat in the back, which, with just two kids isn't used all the time but on average we might need it once a week for school mates and cousins.

Instead of a middle seat there is a shallow tray, which will fit a phone or in our case leaves and rocks found at the park.

So, yes, the Turbo GT is a four-seater only, but this is a spacious, large SUV with good head and legroom, wide-opening doors for easy entry and exit, and air suspension which can raise and lower the height for easy access.

Storage is excellent with enormous door pockets in the front and back and there are four cupholders.

There's a wireless phone charger in the front and two USB-C ports as well, plus two USB-C sockets in the back.

Four-zone climate control means the kids in the back can set their own temperatures. They also have heated seats.

I was disappointed to see there aren't sunshades for the rear windows - pretty vital in Australia where it feels like we're only about 50 metres away from the sun.

The Turbo GT's 576-litre boot just managed to fit our pram and a week's shopping, which is our minimum standard for living. Any more space is a bonus.

The Turbo GT is the king of Cayennes, so it shouldn't surprise anybody that it's also the most expensive with its list price of $364,700.

Lamborghini's Urus lists for $409,744  and is the Cayenne Turbo GT's not-so-subtle Italian cousin, sharing the same platform and engine.

Both are in my mind the best performance SUVs on the planet. It just depends how conspicuous you want to be.

Then there's Bentley's V8 Bentayga which isn't blessed with the Porsche's good looks but would still be all over the Cayenne if the two happened to meet at a race track.

So, why is the GT Turbo the king of the Cayennes? What makes it better? For all the reasons you'd think - it's the fastest, most powerful, most luxurious and most equipped Cayenne in the range.

We'll get into mind-bending engine and performance specs soon, but first let me take you through the standard features on a car that's anything but standard.

Coming standard and exclusively to the Turbo GT are 22-inch 'GT Design' wheels in satin 'Neodyne' with full-colour Porsche centre caps, an active rear spoiler, Turbo GT front apron, dual titanium exhaust, rear apron with diffuser, 'SportDesign' side skirts, wheel arch extensions, a lightweight carbon roof and tinted LED HD-matrix headlights.

Inside, and also exclusive to this grade, is the 'GT Interior Package' with 'Race-Tex' upholstery throughout with 'Deep Sea Blue' stitching on the front seats and centre console and the armrests and dashboard.

There's also the 'Carbon Interior Package' which includes dashboard and door trim elements.

Race-Tex trim is applied to the 'GT Sports' steering wheel, roof lining and gearshift, too.

The adaptive active air suspension, which can lower the car by 15mm, is standard and only available on the Turbo GT, too.

The soft-close doors are standard (a cost option on lower grades), as are the stainless steel pedal covers.

The rest of the features are also found on lower grades and include the 12.65-inch digital instrument cluster, head-up display, proximity unlocking, 12.3-inch multimedia touchscreen with sat nav, wireless Apple CarPlay and Android Auto, digital radio, a 10-speaker Bose sound system, heated front seats, rear privacy glass and an auto tailgate.

Four-zone climate control is standard on the GT Turbo, too, and so are heated rear seats.

Our car had several options fitted such as the front passenger display ($2860) and the Deep Sea Blue Accent Package.

The passenger display is a crowd pleaser, but as a family car my kids felt like they were missing screens in the back seats, too. Well, in my day...

The G580 is powered by four permanently excited synchronous motors, each delivering around a CLA200’s worth of power and torque to each wheel for overall outputs in excess of 432kW/1164Nm.

Each motor has its own two-stage transmission and power electronics for almost infinite fine-tuning of the direction and amount of drive sent to individual wheels. Merc calls it ‘individual-wheel drive’.

As a middle-aged parent with two children, a Porsche that I don't have to crawl into and out of like a cubby house is a great thing.

What's even better is that this ‘easy access' Porsche is every bit as brutally powerful and fast as the quintessentially ‘pure' Porsche, the 911. Actually, it's more powerful and faster.

The Turbo GT's twin-turbo 4.0-litre V8 petrol engine makes 485kW and 850Nm with drive going through an eight-speed transmission to all four wheels.

In comparison, a Porsche 911 GT3 RS, arguably the most brutal and anti-social 911, has 386kW/485Nm.

I haven't made a mistake. Those are the real numbers. And it's only when you step on the accelerator in the Cayenne Turbo GT, and it feels like somebody's sat down on your chest, that you realise what a big deal this is.

That is such a colossal amount of oomph that this 2.2-tonne family SUV can accelerate from 0-100km/h in 3.3 seconds.

The 911 GT3 RS can do it in 3.2 and it has a roll cage and a fixed rear wing the size of a bedroom door.

And yes, we're now coming into a digital age where Teslas and other electric SUVs are quick, too, but can they go around corners like a Porsche Cayenne Turbo GT?

Do they have the same rumble and roar as a twin-turbo V8 that's terrifying and enticing at the same time.

The correct answer is, absolutely not.

Housed in a torsion-resistant casing and embedded low down in its ladder-frame chassis, the G580’s 116kWh two-tier, liquid-cooled lithium-ion battery pack delivers a WLTP-rated range of 473km, or 567km on the more lenient NEDC scale.

‘Eco Assistant’ and ‘Range Monitoring’ functions provide continuous information on battery status, energy consumption and estimated range.

Maximum system capacity is 400 volts which enables 200kW DC charging, meaning a 10 to 80 per cent fill in as little as 32 minutes. Maximum AC charging capacity is 11kW.

Claimed energy use is 23.1kWh/100km, and we saw an average of 28.6kWh across urban and highway running on the launch drive program.

Not exactly a ‘green’ EV choice, then, but it’s worth noting a one-year Chargefox subscription is included to off-set the car’s energy appetite.

Seriously? This is a 2.0-tonne twin-turbo petrol V8 with a 90-litre fuel tank. Even the Porsche specs sheet doesn't understand the question because in the column for fuel efficiency there are three letters - tbc.

My own testing saw me record 22.5 L/100km at the fuel pump, which means I enjoyed driving the car very much.

A little digging around reveals Porsche globally claims the Turbo GT will use 12.6L/100km, over a combination of open and urban roads.

You might not have as much fun as I did but easing back a little might get you closer to the 700km of range this more frugal consumption figure appears to offer.

While efficient it isn't, I'm not going to mark the Turbo GT too much here because compared to its petrol rivals the fuel consumption is what I'd expect from such a high-output heavy SUV.

So, with 432kW and around 1160Nm, even though the G580 weighs in at around three tonnes, you’re talking 0-100 km/h in 4.7 seconds. And this car gets up and goes… like a beast.

What you don’t get is that traditional Merc-AMG G63 V8 rumble, because, of course, no engine. 

But you do get what Mercedes calls ‘G-Roar’, essentially a sound bar at the front of the car also using the audio system inside to give it what is not exactly an engine noise but some sense of the car progressing. And you can turn it off for completely silent running.

‘Electric Dynamic Select’ changes the parameters of the motors, transmission, suspension, ESP and steering as required. On-road that means ‘Comfort’, ‘Sport’ and ‘Individual’ modes, with off-road comprising ‘Trail’ and ‘Rock’. In the Comfort setting drive flows primarily to one axle for optimum energy efficiency.

Suspension is by double wishbones at the front and a De Dion-style live (rigid) axle at the rear. You’ve got the same adaptive-type set-up as per other G-Class models, so ‘Comfort’ and ‘Sport’ modes and of the many traditional G-Class traits this car exhibits, ride quality is one of them.

Even in Comfort you’ll find even little bumps and thumps making their way up into the seat of the pants and the cabin. It is after all a body-on-frame, ladder-chassis type vehicle and that’s not unusual.  

In terms of steering, it’s accurate and road feel is good. You’ve got 275-wide Falken Azenis FK520 tyres that are more on- than off-road focused. The car feels stable and nicely planted on the road.

The physical brakes are by ventilated discs front and rear, and the big rotors are the same size (353mm) all around. They work nicely and feel like a conventional set-up.

Regenerative braking kicks in as soon as you lift off the accelerator pedal. The powertrain is harvesting energy as the car decelerates and there are four levels you can adjust with the steering wheel paddles up to a quite aggressive level - not quite, but close to a single-pedal set-up.

Off-road, the G580’s ‘G-Steering’ system allows the wheels to turn at different speeds to induce slight ‘drift-like’ oversteer and tighten the turning circle. It works beautifully and the car’s fording depth is 850mm, a full 150mm more than internal-combustion G-Class models.

A three-speed off-road crawl function is adjustable to speeds as low as 2.0km/h, and the car is claimed to remain stable on sideways slopes up to 35 degrees. 

Torque vectoring is used to create ‘virtual diff locks’ and there’s a ‘low-range’ setting. Switch to the ‘Offroad Cockpit’ and data including gradient, lateral inclination, compass readings, tyre pressures and the selected G-Mode appear.

A ‘Transparent Bonnet’ function creates a virtual view of what’s approaching and passing under the front wheels to help the driver pick their way through steep ascents or declines.

For the record, the G580’s approach angle is 32 degrees, departure is 30.7, breakover is 20.3 and ground-clearance is 250mm.

And of course, with the wheels independently powered, the G580’s signature move is what Mercedes-Benz calls a ‘G-Turn’ but the rest of the world calls a tank turn.

If you encounter an obstacle that makes forward progress impossible, the system spins the left- and right-hand wheels in opposite directions so this brute can turn on the spot like an M1 Abrams. You can’t help but crack up laughing when executing this extreme party trick!

In terms of miscellaneous observations around ergonomics and the car in general, it has a 13.6-metre conventional turning circle. So if you’re not using the G Turn function in the car park be ready for a sizeable turning arc.

Also, those aero tweaks here and there seem to have had an effect. Wind noise, especially for such an upright, squared-off design is surprisingly modest. And overall, from a build point of view, this car feels as though it’s been carved from a solid piece of metal. In every aspect it presents as a quality item.

Never have I met a car this powerful and superbly athletic that is as pleasurable to drive alone on great, fast roads as it is to pilot at 50km/h in the suburbs with a family on board.

It exceeds my understanding of engineering that something this large can move so quickly. That in an instant can turn and tip into a corner with such precision and effortlessness.

Yet it can switch seamlessly and happily to coping with speed bumps and potholes, delivering a ride so comfortable it'll send babies off to sleep. And it did.

The only issue, and this is such a tiny thing, is the dash-mounted gearshift, which means having to reach up and select Drive or Reverse or Park, which, when executing a three-point turn, is necessarily frustrating.

Still, I'm giving the Turbo GT a 10 out of 10 for driving under all conditions, and we didn't even go off-road, which of course you can do, as long as it's not too wild.

The Porsche Cayenne Turbo GT hasn't been locally crash tested and so doesn't have an ANCAP rating.

That's quite normal for super high-end cars. But, when this third-generation model first arrived in 2017 it was tested by ANCAP's European equivalent, Euro NCAP, and was awarded the maximum five stars.

There's AEB which operates at city, urban and highway speeds, and lane keeping assistance, and lane change assistance which is a form of blind-spot warning, and adaptive cruise control. You can option rear cross-traffic alert, as well.

A space saver spare wheel is under the boot floor.

The G580 is covered by Mercedes-Benz Australia’s five-year/unlimited-km warranty, which remains the standard offering in the premium part of the market and an eight-year/160,000km drive battery warranty.

Service intervals are every 12 months or 20,000km with service plan pricing available over three ($2645), four ($3980) and five ($4670) years. In approximate terms, each workshop visit will cost ‘around’ $900. Not exactly cheap, especially for an EV, but this is no ordinary electric vehicle.

The Cayenne Turbo GT is covered by Porsche's three-year, unlimited kilometre warranty, which is lagging behind in terms of duration even compared to other luxury brands such as Mercedes-Benz, which offers five years.

Servicing is recommended annually or every 15,000km, although there isn't a capped price maintenance plan with final costs determined at the dealer level (in line with variable labour rates by state or territory).