BMW X Models vs Mercedes-Benz G63

What's the difference?

This is a highly competent all-rounder, given that it has the comfort and practicality for urban family duties yet with its revered M breeding can produce a level of performance which, in competent hands, could hold its own at a track day where its capabilities could be safely explored.

The Mercedes-AMG G 63 isn't for shrinking violets. It's bold, fast, and loud, and in second-generation form massively improved dynamically and technically. It's a lot of money, but there's a lot to love, and here's hoping it stays around for decades to come.

The fourth-gen X3, which has a lighter but stiffer body, shares the same wheelbase as its third-gen predecessor but at 4755mm end-to-end it's 34mm longer and it's 29mm wider.

It’s also 25mm lower, which combined with front and rear track-width increases and adaptive suspension damping to sharpen the handling underlines its sportiness and driver appeal, despite a substantial 2055kg kerb weight.

The new exterior design is characterised by short overhangs, flush door handles, a larger ‘split kidney’ grille, new LED taillights and L-shaped light elements for the LED headlights.

The new interior design is a classy mix of soft-touch materials and high-gloss hard surfaces in tastefully contrasting tones. The seats are upholstered in a new synthetic leather called 'Veganza' ('Espresso Brown' in our example) which according to BMW requires 85 per cent fewer CO2 emissions to produce than genuine leather (which is still available as an extra-cost option).

Combined with subtle use of ‘Magnolia’ fine-wood trim inserts, satin chrome, piano black, blue/red M highlights and slender ambient light-strips, it’s a cabin that exudes opulence.

The original (W460) G-Glass, then known as the G-Wagen (or Geländewagen for cross-country vehicle), was launched in 1979 as an ultra-capable off-roader, soon favoured by armies the world over. Arriving here in 1982, its distinctive, slab-sided form remained unchanged over the best part of four decades.

At close to 4.8m nose-to-tail, more than 1.8m across, and a bit over 1.9m tall, the G 63 is now longer (+110mm), wider (+106mm), and fractionally lower overall (-13mm), but still pulls off a convincing impersonation of a bread box.

Merc-AMG confidently quotes a drag coefficient (Cd) of 0.55 for the G 63, which isn't as bad as a brick (around 2.0… I Googled it) although it is in the same league as a heavy truck.

But it's the car's unique, upright stance, complete with pumped wheelarches and old-school flat glass, that sets it apart and draws people in. Looking more like a take-no-prisoners, functional device than a luxury cruiser, I can assure you it attracts as many admiring looks and comments as a low-flying supercar wedge.

The new-gen G 63 features AMG's vertically slatted 'Panamericana' grille, and our test example was fitted with the optional 'Night Package' ($5900) adding a range of dark exterior details including tinted indicator lenses, dark tinted glass, black exterior mirror shells and spare wheel ring, other black trim pieces and painted areas, as well as 22-inch AMG forged alloy rims.

Also worth noting, Merc has retained the G-Class's solid metal door handles, complete with the mechanism's unmistakable 'click-clack' opening and closing sound. Nice touch.

Inside, the biggest change is the upgrade from a conventional dual-gauge instrument cluster and central media stack to a pair of 12.3-inch digital screens, forming a sleek widescreen display, and bringing the G 63 in line with other recent Merc offerings.

Similarly, the gearshift moves from a traditional console-mounted set-up to Merc's 'Direct Select' lever on the steering column (exactly where the indicator stalk is located in 90 per cent of right-hand drive cars).  And the standard flat-bottom, leather-trimmed 'AMG Performance' steering wheel is a racy addition.

Like the exterior door handles, another tip of the hat to the car's heritage is retention of the horizontal grab handle ahead of the front passenger on the dash above the glove box. Nice to have something to hold on to if the going gets rough.

This would make a great family weekend escape machine, for which BMW quotes a 645kg payload rating. It’s also rated to tow up to 2500kg of braked trailer, which could pose a challenge given the relatively low 100kg tow-ball download limit (TBD is typically around 10 per cent of trailer weight).

BMW also does not publish a GCM figure (how much it can legally carry and tow at the same time) so we can’t confirm if it can carry its maximum payload while towing its maximum trailer weight.

Even so, the M50 has a useful-sized luggage area which offers up to 570 litres (or 0.57 cubic metres) of load volume with the rear seat upright.

This expands to 1700 litres (or 1.7 cubic metres) with the rear seat folded flat, which can be handy for a multitude of tasks like transporting a mountain bike or hauling home flat-pack furniture.

There’s comfortable space for the driver and front passenger, along with useful storage including large bottle-holders and bins in each front door.

The centre console has two small-bottle/cupholders plus wireless phone-charging and a pair of USB ports. There's also a glove box plus another box at the rear of the console with a padded lid that doubles as an elbow rest.

The rear bench seat is surprisingly spacious, given that I’m 186cm tall and when seated behind the driver’s seat in my position I still have about 40mm of knee clearance, which is optimised by the concave shape of the front seat backrests.

The spacious and airy feel is enhanced by the ‘panorama’ glass roof which spans the full length of the seating area and allows generous headroom even for tall people.  

However, shoulder room is tight for three adults and the centre passenger’s feet must contend with the transmission tunnel, so even though it would be fine for three kids we’d suggest a limit of two adults for longer trips.

Rear passengers get privacy glass and pull-up roller sunshades, large-bottle holders and bins in each door plus net-type pockets and anchorage points for media devices on each front seat backrest. There are also two small-bottle/cupholders in the fold-down centre armrest.

The rear of the centre console has two USB ports, adjustable air-vents plus controls for zone temperature, airflow preferences and seat-heating.

The bench seat features a 40/20/40 split, which allows the centre backrest to fold forward independent of the two outer backrests to allow long loads like snow skis, home hardware etc to be carried if securely fastened.

A power tailgate provides access to the luggage area, which is equipped with a handy 12-volt accessory socket plus load-anchorage points front and rear, extra storage nooks for small items on either side and a retractable roller-type load cover. Overall, this vehicle offers good practicality for family duties.

The G-Class has never been a particularly squeezy proposition for passengers or cargo, but an extra 40mm in the wheelbase adds even more breathing space.

Getting in is the first step, and it's a big one. At 183cm tall, in an athletic mood, I could grab the A-pillar and swing up into the driver's seat in one vaguely respectable movement.

But, those side steps aren't just for show, and at the end of a long day provide a handy staging camp between terra firma and the lofty pilot's chair.

Once on-board there's plenty of room up front, with adequate storage including a bin between the seats (now with a double door opening rather than a single hinged lid), a modest glove box, oddments space and two cupholders in the centre console, and bins with space for bottles in the doors.

There's a 12-volt power outlet in the front, second row and cargo area, while there are two USB ports in the centre console bin and a charging USB port in the second row.

In the back I could have donned a dusty Akubra and still had headroom to spare, with generous foot room, and a substantial gap between my knees and the driver's seat (set to my position).

A fold-down armrest incorporates a pair of cupholders (as well as a through-port to the cargo space for long items) and there are map pockets on the front seat backs as well as space for bottles in the doors. Two adjustable air vents in the rear of the front centre console, and another pair in the B-pillars also provide climate-controlled air to those in the rear.

With the rear seats upright boot volume is quoted at 454 litres (VDA); enough to easily swallow our three-piece hard suitcase set (35, 68 and 105 litres) or the CarsGuide pram, or a largest-suitcase-and-pram combo.

There are tie-down shackles in each corner of the floor, usefully bright lighting, a netted storage area on the passenger side (containing five fluorescent emergency vests), and folding the 60/40 split rear seat liberates even more space.

Unfortunately, gaining access to that load space is fraught with compromise. First, the single-piece rear door hinges vertically and opens from right to left. No problem when you've nosed into a shopping centre space, but not so great when you're parking nose-to-tail on the left-hand side of the road.

That means you typically have a small space between you and the car behind to get the door open, and when it is at 90 degrees, you're blocked from unloading things onto the footpath until you've shut the door.

As well as that, the door has a full-size spare (alloy) wheel and tyre attached to it. Good because a full-size spare is welcome, and bad because it makes the already bulky door even heavier.

Those keen on towing things will be pleased to hear the G 63 is rated to haul up to 3.5 tonnes of braked trailer and 750kg unbraked.

Okay, you're laying down a quarter of a million bucks ($247,329 before on-road costs) and it's fair to expect some serious tech and standard equipment to keep you feeling warm and fuzzy after you're finished impressing friends and family with the G 63's howling acceleration.

For a start, there's a bunch of leading-edge safety tech on-board (detailed in the safety section below), and as expected that substantial cost-of-entry brings an extensive list of luxury features.

We've touched on the twin 12.3-inch 'Widescreen Cockpit', and available media includes digital radio and TV tuner, internet connectivity and 3D nav (with dynamic route guidance), as well as smartphone integration with Apple CarPlay and Android Auto.

Audio is a thumping 15-speaker, and 590-watt Burmester surround sound system, and the ambient lighting set-up offers a choice of 64 colours.

Also included are 'Multibeam' LED headlights, 'AMG Ride Control' adaptive damping, a 'Parking Package' with 'Active Parking Assist' and 360 camera, a sliding glass sunroof (with tilt function), the selectable AMG sports exhaust system, keyless entry and start, the AMG Performance steering wheel (trimmed in nappa leather), and 21-inch AMG '5-Twin spoke' alloy wheels.

Then there are the three 100 per cent differential locks (plus an 'off-road information centre'), electronically adjustable front seats (ventilated front and heated front and outer rear), steering column and mirrors (with memory function), three-zone climate control, nappa leather upholstery, a leather-finished dashboard with open-pore ash wood trim, a 'Dinamica' microfibre roof liner, and an AMG-specific IWC design analogue clock. Plus, the 'Dynamic Select' system enables a choice of pre-set driving profiles or individual settings.

The optional 'Exclusive Interior Plus Package' ($10,300) fitted to 'our' car adds deluxe nappa hide on the dashboard, door centre panels and grab handle, as well as a diamond quilted treatment on the seat centres, a black 'Dinamica' roof liner, velour floor mats (with edging in nappa leather), a frameless interior mirror and air vents in 'Silvershadow'.

On top of that the test vehicle was optioned with the 'Night Package' ($5900) detailed in the Design section, and Designo 'diamond white bright' paint ($5900) for a manufacturer's recommended list price (MRLP) of $269,429.

That puts the G 63 in the same price and equipment ballpark as the supercharged V8 Range Rover Autobiography ($268,900), twin-turbo V8 Porsche Cayenne Turbo ($239,400), and its Mercedes-AMG GLS 63 sibling ($221,729), powered by a version of the 5.5-litre twin-turbo V8 used in the first-gen G 63.

An impressive trio of alternatives, but in reality the idiosyncratic G 63 doesn't have any direct competitors, and for those who give in to the pull of its powerful tractor beams value-for-money becomes a uniquely personal concept.

According to BMW, the M50 xDrive features the most powerful inline six-cylinder petrol engine fitted to an M Performance model.

This 3.0-litre unit clearly benefits from BMW’s twin-scroll turbocharging technology, which combined with variable valve timing and an extra 13kW/200Nm from the 48V mild-hybrid technology produces a stomping 293kW of power at 5500rpm and 580Nm of torque at 1900rpm.

It also has a ‘boost’ function, which provides an extra burst of power for short periods when maximum acceleration is required when overtaking etc.

It’s activated by the left paddle-shifter on the steering wheel and automatically optimises transmission/chassis settings to suit. There’s also a drive mode selector, with ‘Sport’ offering the most responsive and engaging experience.

The eight-speed torque converter automatic is a refined and efficient transmission well suited to this full-time all-wheel drive application. Rapid-fire manual shifting is also available using the steering wheel paddles.

The G 63's 4.0-litre (M177) all-alloy V8 is closed deck design using direct-injection and a pair of twin-scroll turbos to produce 430kW at 6000rpm and no less than 850Nm from 2500-3500rpm. That's 10kW/90Nm more than the 5.5-litre twin-turbo V8 it replaces!

To improve throttle response and optimise efficiency, the turbos are located inside the engine's 'V', improving air flow and shortening the distance from the exhaust side to the turbos, and in turn, from the turbos to the inlet side.

And the housings on the twin-scroll turbos are divided into two parallel flow channels connecting with separate ducts in the exhaust manifold, allowing fine management of the exhaust gas coming in and pressure going out. Result is more torque and even better response times.

Drive goes to all four wheels via a new 'AMG Speedshift' nine-speed, dual-clutch auto (replacing the previous seven-speed auto transmission) with paddle shifters and a multiple downshift function which will go to the lowest ratio possible as you keep squeezing the shift paddle.

The 'AMG Performance 4Matic' all wheel drive system is front/rear biased 40/60 (50/50 in the previous model), although if you want to head off-highway the G 63 still features three 100 per cent diff locks and low-range off-road gear reduction.

BMW claims an official average combined consumption of 8.2L/100km but the dash display was showing 9.9 at the completion of our 210km test, which included a mix of suburban, city and highway travel.

Our own figure, calculated from fuel bowser and tripmeter readings, came in slightly higher again at 10.5L/100km, which given our test vehicle’s two-tonne-plus weight and performance capabilities is still reasonable economy.

So, based on our figures, you could expect a realistic driving range of around 600km from its 65-litre tank, which prefers premium 98 RON petrol.

Claimed fuel economy for the combined (ADR 81/02 - urban, extra-urban) cycle is 13.1L/100km, with the 4.0-litre, twin-turbo V8 emitting 299g/km of CO2 in the process.

Despite the fact cylinder management tech means the engine will run on four cylinders under light load, and start-stop (with 'glide mode') is standard, we managed 16.7L/100km (measured at the bowser) over a mix of city, suburban and freeway running. To be expected for such a big bus, especially one that constantly tempts you into squeezing the throttle just to hear the exhaust bellow.

Minimum fuel requirement is 98 RON premium unleaded, and you'll need 100 litres of it to fill the tank.

First, the fun stuff. It certainly feels like ‘the ultimate driving machine’ when you slide behind the chunky leather-rimmed flat-bottom steering wheel and hold it in your hands.

The driver’s seat offers not only powered adjustment of backrest and base-cushion rake, but also four-way lumbar support and side-bolsters that can tighten their embrace of your upper torso to contend with high cornering loads.

There’s also manual extension of the base-cushion length for greater thigh support and a big left footrest to brace against, so you could not ask for a more accommodating and purposeful driving position.

The steering is perfectly weighted and the quartet of enormous disc brakes provide ample bite with superb pedal feel. Combined with its adaptive suspension and wide grippy tyres, the X3 is a family car that’s also invigorating to drive, particularly when you select the ‘Sport’ mode.

The enhanced engine response and sharper steering that result (even the instrument panel display changes) make any twisting mountain road an engaging experience, enhanced by an intoxicating exhaust note that only a BMW M six can deliver.

The turbocharged engine offers an unyielding surge of acceleration from well below peak torque at 1900rpm to maximum power at 5500rpm, making BMW’s claim of 0-100km/h in a scant 4.6 seconds sound credible.

You can also manually change gears using the steering wheel paddles, but we found the gearing and shift calibrations so good that we preferred to leave it in auto mode.

However, the X3 M50 has two distinct personalities, as in more relaxed drive modes it’s just as happy serving as practical family transport during the week for grocery shopping, daily school runs and other common tasks.

It’s also a comfortable tourer for family getaways, with long gearing that requires only 1500rpm to cruise at 100km/h where low engine, tyre and wind noise allow highway conversations at lounge room levels.

Let's cut to the chase. The G 63's pure grunt overpowers its challenging aero profile to thrust this boom box on wheels from 0-100km/h in a claimed 4.5 seconds. And believe it or not, despite its greater length and width, it has enough power to punch a 240km/h hole in the air (maximum velocity is limited to 220km/h if you choose not to opt for the 'AMG Driver's Package').

The new electronic architecture brings with it the latest version of Merc's 'Dynamic Select' system with five driving modes adjusting the engine, transmission, suspension, steering and assistance systems right up to maximum attack Sport+ mode.

All 850Nm of peak torque is available between 2500-3500rpm and pinning the throttle anywhere in that band feels like lining up a runway and preparing to rotate for take-off.

The two-stage exhaust flap arrangement allows you to turn the noise up from growl to roar even at modest around town speeds, and the nine-speed transmission is sharp and positive, with the multiple downshift function (in manual mode) hilariously good fun.

The racy AMG sports seats are as grippy as they are comfortable, and the fat 295/40 Goodyear Eagle F1 rubber, wrapped around the optional 22-inch forged alloys, does a good job of keeping all that mass and momentum in control as the high riding G 63 careens around corners.

And speaking of mass, the job of hauling it from warp speed to rest sits with big ventilated discs all around (cross-drilled 400mm front/370mm rear), clamped by monster six piston calipers at the front and single piston at the back. They're progressive and reassuringly powerful.

So, the performance is as dramatic as ever, but when I think of previous Merc-AMG G-Class offerings, two main shortcomings come to mind... steering and ride.

The steering was like a laggy mouse, with a few beats separating input at the wheel from response at the front treads. And the damping came up short, with a bouncy ride par for the course.

Still sitting on a ladder-type frame, the new G's suspension was developed by Mercedes-Benz and Mercedes-AMG. And finally, it has a decent double-wishbone independent front-end, with a rigid axle at the rear and coil springs all around. Plus, a strut tower brace, Merc-AMG calls it a 'suspension bridge', now connects the front strut towers, increasing torsional rigidity.

Ride comfort, especially in the most compliant 'Ride Control' suspension setting and riding on the big 22s, is massively better. It's no limo. You'll still feel jittering over higher frequency imperfections. But it's way, way ahead of the first-gen version.

The steering system changes from a recirculating ball to rack and pinion, and is now variable ratio with electro-mechanical rather than purely hydraulic assistance. And it's also much improved. We're not talking about a Lotus Elise-style connection with the road, but the steering is clearly more predictable and responsive.

One thing that hasn't changed is an ocean liner-worthy, 13.6m turning circle. You'll need to plan ahead for U-turns and reverse parks, but enough parking cameras (including surround view) to please Cecil B DeMille are on hand to help.

It's like a whole new world with a familiar cover wrapped around a markedly improved package. But (there must be a but) visibility is still compromised by thick window and door pillars, and despite the new dash layout ergonomic efficiency is patchy, with some switches and knobs located in relatively awkward positions.

As mentioned earlier the G 63 features three 100 per cent diff locks and low-range off-road gear reduction. But forget breakover angles and wading depths. This 4x4 seeing off-road action is as likely as an Abbott 2.0 prime ministership.

Suffice it to say, this car wears the 'Schöckl' badge at the base of its B-pillar. And in case you were wondering, Schöckl is a 1445m mountain in Graz, the Austrian city where the G-Class is built (and big Arnie Schwarzenegger was born!).

In the second-gen G-Class's development, prototypes covered roughly 2000km over a five kay trail including gradients of up to 60 per cent and lateral inclines up to 40 per cent. So, despite its irrelevance, the off-highway box is ticked.

The second-gen G 63 hasn't been assessed by ANCAP or Euro NCAP but its new electronic architecture brings the car up to speed on active safety tech, now incorporating 'Distronic' cruise control with 'Active Distance Assist', 'Active Brake Assist', AEB (forward and reverse), 'Active Lane Keeping Assist', 'Blind Spot Assist', 'Adaptive High-Beam Assist', tyre pressure monitoring, and 'Traffic Sign Assist'. Plus, the 'Pre-Safe' system prepares the vehicle and occupants in the face of an inevitable collision.

And once that impact has occurred, you're protected by nine airbags, including rear seat airbags, full-length curtains and a driver's knee bag.

There are three top tether points for child restraints/seats across the back seat, with ISOFIX anchors in the two outer positions.

It comes standard with a five-year, unlimited km warranty.

Scheduled servicing is determined by BMW’s vehicle monitoring system which advises when a service is needed, typically around 12 months/15,000km.

A capped-price servicing package covering five years/80,000km (whichever occurs first) totals $2475, or an average of $495 per service.

Mercedes-Benz (and by extension Mercedes-AMG) offers a three-year/unlimited km warranty with 24 hour 'Road Care' emergency roadside assistance provide for three years.

Servicing is recommended every 12 months/20,000km and a capped price servicing plan is available at Silver and Platinum levels for up to five years/100,000km.