Lexus Gx550 vs Mercedes-Benz G63

What's the difference?

The new Lexus GX 550 Sports Luxury looks fantastic and has enough mod cons to satisfy a family but it’s not as luxurious as you’d expect from a premium brand and the fuel economy and driving range will turn off some. But if you’re still interested, there’s a lot here that will make you happy and it’s one of the smoothest 4WDs I’ve driven.

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 new GX 550 looks massive and while it shares the same platform as the Toyota LandCruiser 300 series, it doesn't share all of its bulk. They both stand at 1980mm wide but differ on length (5015mm vs 4980mm) and height (1670mm vs 1950mm), respectively.

The new design is fabulously rugged but each body panel looks meticulously crafted and is just the right size. This just means the proportions look right and your eye sort of glides over the big body rather than stopping on any one feature.

But having said that, there are a lot of nice features to focus on, like the long LED headlights and rear strip light, auto-folding side steps, 22-inch alloy wheels and sharply styled rectangular side mirrors.

The tailgate window can also be opened if you need to pop something into the boot but don't want, or have the space, to open the tailgate itself.

The styling takes a minor nose dive once you hit the cabin, though, because it doesn't look as sumptuous as you'd expect in a premium SUV.

I love the utilitarian and military vibe of the vertical dashboard, chunky air vents and relatively small windscreen. It looks great but some trims are plasticky and the touchpoints, while soft, are not Lexus-plush.

However, the technology looks gorgeous with an integrated 14-inch multimedia display and a 12.3-inch digital instrument cluster. The fixed sunroof with its two settings (clear or opaque) is also a lovely feature.

But on a whole, the GX 550's European rivals outclass it with their flashier cabins.

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.

The cabin of the new GX 550 is fairly practical with plenty of head- and legroom in each row (yep, even the third!). When you first hop in, it can feel a big snug on elbow-room but this feeling quickly dissipates.

Despite a 215mm ground clearance, access is pretty good for the front and middle rows due to the wide door apertures and side-steps. Third row access is a bit awkward for an adult but my eight-year old loved scampering back there this week.

The electric front seats are comfortable with their extra functions and I like the way the massage feature extends to the seat cushion as it limits fatigue on longer journeys. However, you sit on top of them rather sink into them which makes it feel a little trucky at times.

The wide middle row has a bench seat that will be comfortable for kids but an adult might get a sore behind on a long trip. The transmission tunnel also compromises foot room for adults but the seat is wide enough to make use of all three top-tether anchor points (there are ISOFIX mounts too).

It was a little bit of an effort to lift my big booster seat into the back because the GX 550 sits so tall but otherwise, there's plenty of room around a child seat for them not to feel like a sardine.

Individual storage is made up of a glove box that fits an owner's manual, a small shelf in the dashboard and a middle console that doubles as a cool box (mini fridge) and can fit up to four cans or bottles in it.

Each row gets four drinkholders and two USB-C ports but the front also enjoys a 12-volt socket and wireless charging pad. There's a 220V domestic plug port in the boot for larger appliances, too.

It's sometimes awkward to use the wireless charging pad because it's easy for your phone to slide around on it and it quite often disengaged from charging.

My son enjoyed all of the other amenities in the middle row, like the reading lights, climate control, two USB-C ports and retractable sunblinds and I applaud carmakers when they position rear directional air vents in the pillars and/or roof. It just makes it so much easier to cool down sweaty kids!

The 14-inch multimedia display has clear graphics and a responsive touchscreen. The layout is easy enough to get used to after spending some time with it and the sat nav is simple to use.

I like that the sat nav directions can be pulled into the 12.3-inch digital instrument cluster and head-up display.

There is a Lexus connected services app, which you get a three-year subscription to. It's easy to connect to the wireless Apple CarPlay and there is also wireless Android Auto.

The system also has Bluetooth and digital radio, which is a delight to use through the 21-speaker Mark Levinson sound system.

The cabin is rounded out by the well-shaped boot which has a massive 1063L of capacity when the third-row is folded. That's been more than enough for my family's needs this week and my German Shepherd was pretty comfy back there, too. The powered tailgate has a kick-function and there is a full-size spare wheel underneath the car.

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.

All GX 550 grades share the same 3.5L V6 twin turbo-petrol engine which produces up to 260kW of power and 650Nm of torque.

This 4WD has high- and low-gearing, as well as a bunch of driving modes to suit most occasions, like 'Eco', 'Comfort', 'Sport' and 'Sport+'.

The 10-speed automatic transmission shifts through its gears smoothly and it always feels like it's engaged in the right gear. Which isn't always the case for a big SUV!

The Sports Luxury is fitted with a towing hitch and cover but unlike the base Sports grade which has a 3.5-tonne braked towing capacity, this model only has a 3130kg capacity which might not appeal to families with big toys to tow. 

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.

I didn’t have high hopes for fuel economy because the official combined (urban/extra-urban cycle figure is a hefty 12.3L/100km but after mostly open-road driving, with some urban stuff mixed in, my real-world average came in at 11.8L.100km! This figure is based on my actual km travelled (358km) and litres of fuel used (42.41L).

While I’m surprised by the fuel usage result, I wouldn’t say this car has good fuel economy compared to its diesel-powered counterparts but it’s not terrible!

The GX 550 has a relatively small fuel tank compared to its Toyota cousins at 80L and based on the combined fuel cycle, you’ll get a theoretical driving range of up to 650km.

Not all that great. Not for a big family mover and not if you’re typically driving in the city, where fuel usage will be a lot higher.

The GX 550 only accepts premium unleaded petrol (95 RON), too.

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.

Oh my goodness the Sports Luxury is a masterclass on 4WD refinement! You never feel the bulk or weight of this massive SUV when you’re driving it. The power delivery is effortless and there’s lots of grunt available when you hit hills.

The handling is also very good with responsive steering and enough road feedback as a driver to make you feel comfortable with what the car is doing. There is some roll in corners but it can tackle more corners at speed than I thought it would. 

The high driving position makes me feel like I can see a long way ahead yet while visibility is mostly good, it can be compromised when you have the side window shades and the third row headrests up. Which is why I love the digital rear view mirror.

Overall, ride comfort is good with forgiving suspension and low cabin noise, even at higher speeds. It’s pretty easy to chat with all rows and there’s not a lot of engine noise which adds to the refinement. I do like hearing a V6 rumble but that’s just a personal preference. 

I was a little worried about hitting my local Westfield car park but this is a nimble SUV to manoeuvre and parking it is a breeze with the 360-degree camera system and parking sensors. 

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.

Lexus offers the GX 550 with a five-year/unlimited km warranty, which is fairly standard compared to its Euro rivals.

You get five years capped-priced servicing which costs $5950 but the servicing schedule is a bit of a bear at every six months or 10,000km, whichever occurs first.

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.