Mercedes-AMG S63 vs BMW X5

What's the difference?

Both of these vast vehicles are phenomenally comfortable - this is the kind of car that Mercedes does so well, and has done for decades. The S Class is rarely a disappointment but it's difficult to believe that such a big, heavy GT car can also dance the way the S63 does.

The S560 is far more weighted to being a GT - supremely comfortable with that active suspension, a growly, refined V8 and a cabin full of gadgets and comfort. The S63 is altogether more aggressive, to look at and to drive. Lopping the roof off both of them adds weight but, like any cruiser, also puts you out in the sun, the breeze and into your surroundings. Plus, in the case of the S63, you get more exhaust noise.

They're two very different cars and not just because of the engine. After all these years admiring it from afar, the S63 has delivered on my teenage expectations - fast, smooth and utterly mad.

This is a luxurious prestige five-seater brimming with BMW’s latest design and technology that’s not only practical for weekly family duties but can also embrace spirited driving with the push of a button. A great all-rounder for families that like a sporty edge. 

The S Class Coupe is obviously related to the sedan but manages a svelte appearance. Slimmer hipped and with a more Coke-bottle shape, the Coupe - if you squint a bit - has a bit of the classic old pagoda about it. Obviously you can't do pillars that slim anymore, but the glass roof takes away some of the visual weight inside and out. 

The cabriolet's roof is nicely integrated and looks good when it's  up, which isn't always the case.

They all look long, though. It's obvious to see why the cars all run on 20-inch wheels - anything smaller would look hilarious.

The cabin is a fairly sensible re-imagining of the E-Class. The big twin-screen layout of the dash and multimedia system seems a bit more at home here. The chintzy Burmester speakers in the doors let down an otherwise classy cabin, which steers clear of otiose vulgarity in looks and materials.

The latest front-end design features subtle revisions to BMW’s signature 'kidney' grille theme, highlighted by slimmer matrix LED headlights with chevron-shaped DRLs that incorporate the turn indicators.

There’s also an ‘iconic glow’ function, which illuminates the twin-grilles at night in-sync with the external courtesy lights when approaching and departing the vehicle. Lower front air-intake and tail-light treatments have also been revised.

The dash features a new curved instrument panel. Based on BMW’s latest generation 'iDrive' operating system, it consists of a 12.3-inch driver’s info display and 14.9-inch control display presented across the same seamless glass surface.

The control display’s touchscreen functionality has allowed dash buttons and switches to be minimised.

This new design dash has a blend of synthetic leather trim and dark brown/high-gloss woodgrain surfaces, along with new LED ambient lighting and gear-selector design.

The rear seat is sumptuous and spacious, even for someone my height (186cm). There’s ample knee and headroom and it can seat three kids in comfort, but for adult passengers wanting that 'business class' feel it would be ideal for two.

My only criticism of the new instrument display is that with more than 30 applications displayed on the expansive control screen, it can be distracting at times trying to visually locate and operate these functions while driving.

And, depending on sun angle, there were also complaints from different front seat passengers on different days about blinding glare caused by the dash’s high-gloss woodgrain inserts. Fortunately, the driver is unaffected by these reflections.

Well look, if you end up in the back of the S Coupe, it's not a riot of space. Obviously it has back seats (the SL doesn't even squeeze a jump seat into its considerable length) but they're for occasional, if luxurious, use.

The boot is a reasonably decent 400 litres, obviously the cabriolet loses a few litres with the roof folded. Front and rear passengers will both enjoy a pair of cupholders and the whopping long doors will each hold a bottle.

With its 2165kg kerb weight and maximum allowable weight of 2885kg, our test vehicle can legally carry up to 720kg.

That should be ample for five adults (even better for kids) and their luggage, of which up to 100kg can be carried on the roof rails using a rack or roof box (both in BMW's accessory range).

Powered upper and lower tailgates provide good access to the luggage area, which is carpeted and equipped with a roll-out privacy screen, load securing hooks, a 12-volt accessory outlet and a first-aid kit stored behind a removable side panel.

The space-saver spare and tools are stored below the hinged load floor, so all luggage must be removed to access them.

Internal luggage space with the rear seat upright is 650 litres (0.65 cubic metres) which expands to 1870 litres (1.87 cubic metres) with the rear seat folded flat.

A useful load-carrying feature when the rear seat’s backrest is upright is a hinged centre section that folds forward and flat to carry long and narrow items.

These can stretch all the way from the tailgate to the dash if need be, which could be handy for carting anything from skis to home hardware purchases (firmly secured, of course).

It’s also rated to tow up to an impressive 3500kg of braked trailer, which matches the class benchmark for one-tonne utes.

However, given that tow-ball download (TBD) is usually around 10 per cent of trailer weight, the X5’s maximum TBD rating of only 140kg could be a challenge if 3500kg towing is required.

Front of cabin storage includes a big bottle-holder and bin in each front door, a glove box and on the right-hand side of the dash a pull-out driver’s bin, both of which are felt-lined.

The centre console, in addition to its wireless phone-charging pad, USB-A port and 12-volt outlet, has two small-bottle/cupholders up front and a large box at the rear, housing a USB-C port and topped by a padded dual 'brochure fold' lid that double as an elbow-rest for driver and front passenger.

Rear seat storage includes a large-bottle holder and bin in each door and pockets on each front seat backrest. The rear of the centre console has two storage nooks for small items in addition to its air-vents, two USB-C ports and a 12-volt outlet. There’s also a handy tablet-mount and USB-C port on each front seat backrest, which is great for long trips.

Folding down the rear seat’s centre armrest reveals two pop-out small-bottle/cupholders. And under its hinged lid is a hidden felt-lined compartment that’s ideal for storing slim screened devices away from prying eyes.

Our test vehicle, to use its full name, is the X5 xDrive 40i M Sport. That breaks down to xDrive (intelligent all-wheel drive) and 40i (3.0L turbo in-line petrol six) with eight-speed automatic transmission.

M Sport denotes a package that's included as standard equipment which contains desirable goodies like enormous multi-piston M Sport brakes/adaptive suspension/aerodynamics, M leather-rimmed steering wheel, high-gloss black roof-rails and more.

All up, the list price is $138,900. However, our example has an optional ‘Enhancement Package’ which for another $6000 adds your choice of selected 22-inch alloy wheels (fitted with 275/35 R22 Continental tyres on ours), a tyre pressure monitoring system, metallic paint ('Skyscraper Grey' on ours), Harman Kardon 16-speaker surround-sound audio and 'Crafted Clarity' glass application (glass-handled shifter).

And this is on top of many standard features including three-zone climate control, automatic two-piece tailgate, digital radio, a head-up driver display, adaptive LED headlights with high beam assist, a panoramic full-length sunroof, wireless Apple/Android integration, 'Verino' quilted synthetic leather upholstery, numerous USB ports/12v outlets and more. However, there’s only a space-saver spare.

Numerous options include self-levelling air suspension, 'Merino' leather upholstery, active seat ventilation and massage functions, thermo-adjustable cupholders, LED-illuminated ‘sky lounge’ panoramic glass sunroof and Bowers & Wilkins premium surround sound to name a few.

All four coupes and cabriolets ship with Daimler's formidable 4.0-litre twin-turbo V8. The S560 scores 345kW/700Nm to drive the rear wheels through Benz's own nine-speed automatic. With all of that available, the S560 will crack the ton in 4.6 seconds and make a wonderful racket on the way.

Moving on to the S63, the same engine delivers a massive 450kW/900Nm. The run from 0-100km/h is dispatched in just 3.5 seconds and if I thought the S560 made a good noise, the S63 with its standard sports exhaust makes a better one. Again, Mercedes' nine-speeder is along for the ride.

The X5 xDrive40i is powered by BMW’s legendary 3.0-litre DOHC 24-valve in-line six with state-of-the-art technology.

This includes twin-scroll turbocharging, variable valve/camshaft timing and 48-volt mild hybrid technology (delivering up to 9.0kW and 200Nm) using an electric motor integrated with the transmission.

The combined effect is optimised power and throttle response (0-100km/h in 5.4 secs) with minimal fuel consumption and Euro 6d emissions.

It produces 280kW between 5200-6250rpm and 520Nm of torque (this can reach 540Nm with hybrid input) across a remarkably wide and flat peak torque band between 1850-5000rpm, which showcases its flexibility. There’s also auto start-stop and selectable drive modes.

This is paired with BMW’s smooth and sharp-shifting eight-speed torque converter automatic, which combines the best characteristics of a dual-clutch and traditional torque converter transmission.

There’s overdrive on the seventh and eighth gears to optimise fuel economy and the choice of rapid manual-shifting using the steering wheel paddles.

Power reaches its wide tyres through the xDrive intelligent all-wheel drive system, which actively varies the engine’s torque distribution between the front and rear wheels to optimise traction at all times.

BMW’s ‘Efficient Dynamics’ also includes brake energy regeneration with recuperation display and many other standard features to enhance driving safety and efficiency.

The lower-powered 560 drinks 98RON at the rate of 8.5L/100km for the coupe and 9.9L/100km for the heavier cabriolet.

The S63 ups the ante with 9.9L/100km for the coupe and an identical 9.9L/100km for the cab.

Our launch program contained some...er...spirited driving, which would explain the mid to high-teens fuel figures.

BMW claims combined average (WLTP) fuel consumption of 9.9-8.5L/100km. Our 415km test comprised a mix of suburban and highway driving and when we stopped to refuel the dash display was showing 10.2L/100km which was line-ball with our own 10.6L/100km figure, calculated from fuel bowser and tripmeter readings.

So, based on our figures, you could expect a realistic driving range of around 780km from its 83-litre tank using standard 91-octane petrol.

Let's start with the S560. That smooth V8 rumble is all you'll ever hear if you just slot into drive and go for a leisurely spin. The nine-speed automatic continues to be a revelation to me - in the GLC63 it's good and here, once again, it's excellent, finding the right gear for the occasion and riding the fat torque curve. Other nine-speed autos are not very good at all.

The test route for the S560 played to the strengths of the car. It had some lovely winding roads, which brought the trick suspension into focus - the Magic Body Control with curve function is hilarious. While the active suspension works hard at all times to ensure the ride is smooth and drama free, the Curve mode (no, really) actually leans the car into corners.

Those of you who remember the video game Wipeout 2097 will be big fans of Curve mode. As you approach a corner, you turn the wheel and then the car leans into the bend. This isn't active damping reading the road, it's the outside suspension lifting the car and the inside lowering it, so the car feels like it's gliding, like a hovercar. It's wild but oddly calming. Mercedes reckons it's great for those who get car sick. As I didn't have my wife on hand to test this theory - she chucks at the first sign of a corner - I couldn't verify this claim. That will have to wait.

The S63 AMG is a completely different proposition. The air suspension is more than up to the job of helping smother the effects of the car's considerable weight, meaning that no matter what you're up to, the car feels reasonably light on its feet. It never feels small, though, commanding the respect of the driver and plenty of space from other road users.

And boy, do you need some space if you kick the S63 into Sport mode. In true AMG style, the electronic reins relax and the big luxury coupe cheerfully kicks off. The tail will wriggle under an unsympathetic right foot, that signature V8 roar, crackle and hiss filling your ears. The S63 is always the harder-feeling car, but it delivers with a more sporting drive than the S560.

Being the generous soul I am, I volunteered to return the S63 to its home for the evening rather than consign it to the back of a truck. On the back roads I took to reach the highway, it was rock solid - fast, predictable and a lot of fun. Once I found the boring straight bits, it turned into a supremely comfortable cruiser, ticking along in ninth at the legal limit (and being Melbourne, it was very much the legal limit), dispatching overtaking with barely a flex of a toe. 

The active cruise took the stress of keeping away from the State Revenue Office's clutches while being quiet and utterly pleasant.

It’s supremely comfortable, with front bucket seats that offer powered-adjustment of height, reach and backrest angle along with side bolsters that can tighten their grip of your upper torso.

There’s also two-way lumbar support, that adjusts not only how far it pushes your spine forward but also allows that pressure point to be raised or lowered.

Combined with its power-adjustable leather-rimmed steering wheel, it would be hard not to find a comfortable driving position.

Eyelines to all mirrors are good and over-shoulder blind-spots are minimal. Front and rear occupants can talk without raised voices thanks to low engine, wind and tyre noise at highway speeds.

As you’d expect, it has high build quality and a tangibly solid feel as though it was machined from a single block of steel, from the satisfying thuds of its closing doors to the absence of shudders or rattles on a variety of roads.

It also has two personalities, which can be switched in an instant. In 'Comfort' mode it will happily cruise around city and suburbs as a mild-mannered family car, fulfilling daily duties like work commutes, school drop-offs and pick-ups, supermarket shopping and the like.

However, flick the drive mode to 'Sport Plus' and you awaken, well, if not ‘the ultimate driving machine’ then something close.

Its optimised drivetrain and handling settings feel more like a sports sedan than a family car, which can turn any winding mountain road into an engaging experience.

It has impressive reserves of cornering grip and braking force, combined with sparkling engine response and fast sequential manual-shifting at your fingertips.

It feels impressively agile, with all-round response that belies its 2.0-tonne-plus kerb weight, backed by a symphony of sounds from its sublime in-line six.

Five-star ANCAP (awarded in 2018) includes front and side airbags for driver and front passenger, plus head airbags for front and rear seats.

The comprehensive 'Driver Assistant Professional' active safety menu includes AEB (city, interurban and vulnerable road user) and a multitude of others.

It also has 'Parking Assist Professional' and for young families there are ISOFIX child seat anchorages on the two outer rear seating positions and top-tethers for all three.

Mercedes offers a three-year/unlimited-kilometre warranty with roadside assist for the duration.

The company also offers both service plans (where you pay up-front as part of the vehicle purchase) and capped-price servicing on the coupes. Servicing over three years is in the order $2500.

BMW covers the X5 with a five year/unlimited km warranty and offers several service plans to suit different budgets and requirements.

For example, the 'Service Inclusive Basic' package covers all scheduled services over five years/80,000km for a total of $3450, or an average of $690 per year.