Mercedes-Benz X350 vs Porsche Cayenne

What's the difference?

The V6 X-Class is nice enough to drive on-road and it’s effective enough off-road, but it’s let down by its less-than-impressive interior and those elements combined certainly do not justify such a high price-tag.

Sure, its safety gear is top-notch but the X-Class, even in this V6 guise, feels like a lacklustre attempt at ute greatness, rather than a real effort. 

Right now, if you’re in the market for a super-comfortable and capable V6 ute with real class and German precision, check out a top-spec V6 Amarok – and save about $25,000 while you’re at it.

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.

From the outside, the X-Class looks pretty impressive – it’s chunky and blocky and has a real tough-truck presence.

As mentioned, a fair few of the cool exterior touches are actually paid-for options, and our tester was loaded with these extras and, as a result, looked like a work-or-play ready luxury workhorse.

So, it looks pretty good but, as always, looks can be deceiving and the interior is a very different story.

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.

I’m not a snob about interiors but if I spent almost $90 grand on a ute I’d expect it to have a very high level of fit and finish inside, plenty of storage options and an overall premium feeling inside.

That’s sorely lacking in here.

From the many hard-plastic surfaces, fake leather, brushed-aluminium sections and sort of half-hearted attempts at three-pointed star styling – such as the vents – no part of the interior looks or feels anything like the premium quality you’d expect to find in a Mercedes-Benz.

As for equipment inside, you get the 7.0-inch floating touchscreen and a few other bits and pieces but there are some glaring omissions: you don’t get a reach-adjustable steering wheel, heated seats, or real leather (our tester has the optional black leather seats fitted at a cost of $1750), you don’t get much in the way of storage anywhere, and you don’t get Apple CarPlay or Android Auto – you don’t even get a driver-side grab handle. All of those sort of mod cons, you get in a ute that costs much less than this X-Class. 

Room and comfort inside is adequate but a long way from unreal for something so pricey.

Driving position is nice, with plenty of vision all-round, but everyone's seats could do with a bit more cushioning and length in the base.

In the grand tradition of all utes, the rear seat is really the realm of young children and, at a stretch, smaller adults, especially for longer trips in the saddle. 

Storage is minimal in the back seat – you don’t even get a drop-down arm-rest with cup-holder.

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 V6 350d Power V6 has a Benz-built 3.0-litre diesel engine (190kW at 3400rpm and 550Nm at 1400rpm-3200rpm), matched to a Benz-built seven-speed auto. It’s a mostly smooth combination and any perceived throttle or turbo lag can be swiftly overcome through switching to one of the more sporty of the five driving modes – one of which is actually called Sport – and making judicious use of the steering-wheel-mounted paddle shifters. The other driving modes are Comfort, Eco, Manual and Off Road and all are designed to adjust throttle input, gear changes and shift times to suit the terrain.

This X-Class has Benz’s 4Matic full-time 4WD system with 4MAT (40:60 torque split for daily driving), 4H (the X-Class’s high range, with 30:70 torque split for looser surfaces) and 4L (aka low range with a 50:50 torque split to suit low-speed 4WDing). The driver uses a simple dial – unfortunately tucked away low down, almost hidden, on the centre console – to switch between these modes.

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.

Fuel consumption is listed as 8.8L/100km (combined). 

We recorded 10.9L/100km on test and that included plenty of low-speed 4WDing. 

The V6 X-Class has a 80-litre fuel tank. 

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.

Well, this is where the news gets a little bit better.

The V6 is a much better fit for the X-Class than the four-cylinder and it works well with the seven-speed auto, punching the more-than-2190kg ute along – although there is, at times, a substantial delay between foot down and go-time but, as mentioned earlier, that can be overcome by switching to Sport and using the paddle shifters.

It does sit nicely on the road, and ride and handling are generally okay with the X-Class only infrequently revealing some of the skips and jitters you’d expect of an unladen ute.

The coil-spring suspension tends to yield a spongy, comfortable ride rather than the too-firm ride of a ute, especially those of the leaf-spring variety, with nothing onboard.

Steering is pretty sharp and, despite its bulk, the X-Class is reasonably easy to manoeuvre for its size on- and off-road. It has a 12.8m turning circle.

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.

A three-year/200,00km warranty applies to this ute. Service intervals are up to one year/20,000km.

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).