Lexus RX vs Mercedes-Benz G-Class

What's the difference?

So, is the latest Lexus RX good enough to stay, or should it sashay away?

In almost every single way except accessibility (the cheapest is now $15K more expensive, remember), the newcomer is hugely better than the model it replaces, with a level of sophistication and refinement – as well as comfort – that the underwhelming predecessors just could not manage.

And, yes, while there is tech shared with the Toyota Kluger (as there's always been), RX #5 looks, feels and drives much more like a large luxury SUV should.

Speaking of which, few rivals can match the family-friendly RX's combination of customer service, glamour and opulence.

Our verdict then? This Lexus has gone from being a drag to one of the queens of the BMW X5 class. RX... Shantay, you stay!

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.

They used to say that the revolution will not be televised.

At first glance, the same also applies with this fifth-gen RX, since all the big changes are largely out of view.

Precisely how different it looks depends on which angle you're looking at it from.

Observing nose-on, the RX's front tracks and body are wider and it boasts a new Spindle Body grille design which is meant to have a 3D effect, but is quite fussy to some eyes. And this is meant to carry on through to all future Lexuses, by the way.

Yet, in profile, the newcomer is hard to distinguish from the old one, with its returning floating roof C-pillar motif, which looks quite sleek. Yet the wheelbase has been stretched, which results in 60mm more interior space, and that benefits overall proportions as well as occupants.

Some reckon the strip tail-light design and clean surfacing make the rear the RX's most arresting angle.

Note that Lexus has dropped the old RXL seven-seater model – it didn't sell very well. A replacement is coming but it won't be anything like the new RX. Stay tuned to CarsGuide for more on that in the not-too-distant future!

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.

At nearly 4.9 metres, the RX is deceptively long, and that pays dividends inside, while a larger and roomier cabin are the main beneficiaries of that stretched wheelbase.

Step inside, and you're greeted by a modern, attractive and functional dashboard that looks and feels upmarket – even in the least expensive version. This isn't always the case with luxury SUVs. You're not aware of corners being cut or cheap materials. It all seems really well crafted.

Sumptuous front seats provide loads of squishy, cushy comfort as well as adjustability to help find the right driving position for you. Taller people can now sit lower down if they like, meaning it's less cramped for them now. In fact, most occupants will find the RX pretty spacious up front.

Lexus has also worked hard to right other previous wrongs as well.

While not especially pretty or distinctive, the instruments are clear and informative, providing a wide array of driving, vehicle and multimedia data as required. That old intimidating tech-overkill presentation has been binned. Mercifully.

For example, the central touchscreen now features shortcuts for the most often-used items, so you're not forever diving into menus and sub-menus for climate control, navigation, audio, vehicle settings or phone access. And there's now a 'Hey, Lexus' voice control function to further aid useability.

Other plus points up front in the latest RX include an excellent audio system, extremely effective yet unobtrusive ventilation, and loads of storage – whether in the decently sized glovebox, beneath the vast centre armrest or within the deep door pockets.

And while they might need a moment to get used to, the e-latch electric door handles soon become second-nature to operate. And they provide a potentially life-saving extra bonus.

Speaking of which, there's even more surprise and delight to help you connect with the RX emotionally. It isn't all about wearing sensible shoes in here.

For instance, the big 14.0-inch touchscreen looks and feels contemporary yet is wonderfully user-friendly. It actually invites you to play around with it. The dashboard's horizontal themes create a sense of width and space that's... freeing. There are far fewer buttons than before, down from 81 to 50, though they're also still around for vital functions like audio volume control. And on some grades, the varying ambient lighting choices include exhilarating, relaxing and arousing.

But while this interior is a huge step forward and one of the most appealing aspects of this latest RX, there are some misfires remaining.

Chief among them is the infuriating cruise control buttons with their new-fangled 'capacitive touch' tech, which is fiddly to use and alarmingly distracting. This is a throwback to the infernal mousepad controller found in older models.

The same applies to the camera-based rear-vision mirror found on higher grades, which can induce nausea at a single glance. Did Lexus actually test this on humans beforehand?

Moving to the rear seat, it's clear the company did put the family first, with that stretched wheelbase and extra legroom it liberates. Your 178cm tester found ample headroom, legroom and kneeroom sat behind a front seat set up for them. Meanwhile, the cushion is well padded and the (reclinable) backrest comfy.

Amenities include face-level air vents, climate controls, USB ports, a centre folding armrest with cupholders and storage, overhead lighting and grab handles, deep door pockets and a decent view out.

Overall, that premium feeling up front continues out back too.

And great news for family car buyers – the latest RX's has a larger boot, it now measures in at 612 litres (and expands to 1678L with the rear seats folded down), and comes with a long, flat floor with some storage underneath.

Note, though, that only the F Sport has a temporary spare wheel – the rest make do with a tyre repair kit.

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.

As per the Toyota RAV4 hybrid, the RX350h uses a 2487cc 2.5-litre four-cylinder petrol engine producing 140kW of power at 5200rpm and 239Nm of torque from 4300-4500rpm.

Combined with a 134kW/270Nm synchronous permanent magnet electric motor and nickel-metal hydride battery, it drives the front wheels via a continuously variable transmission (CVT). Maximum system power is 184kW.

The sprightlier E-Four option adds a second electric motor on the back axle to provide AWD. It betters the 2WD's zero to 100km/h sprint time of 8.1 seconds by 0.2s.

Next up is the RX350, which swaps out the hybrid tech for a 2393cc 2.4-litre turbo unit, pumping out 205kW at 6000rpm and 430Nm from a low 1700-3600rpm, while driving all four wheels via an eight-speed torque-converter auto. Its 0-100km/h time is 7.6s.

Finally, there's the RX500h hybrid, combining the 350's 2.4L turbo (producing 202kW at 6000rpm and 460Nm from 4300-4500rpm) with two electric motors (one on each axle) and a unique six-speed auto, for a combined 273kW. It's rapid too, reaching 100 in just 6.2s.

Oh, by the end of 2023, the RX450h+ plug-in hybrid electric vehicle (PHEV) will also be part of the line-up.

On all models, suspension is the tried-and-tested MacPherson-style struts up front and a multi-link rear arrangement. The RX's platform is new, sharing the TNGA Toyota New Global Architecture with the Camry, RAV4, smaller NX and – you've guessed it – the latest Kluger.

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.

No shocks here.

The RX350 turbo slurped 11.0L/100km over our launch drive route, which took in both peak-hour traffic jams and rural highway runs, compared to 9.6L for the 500h hybrid turbo and just 6.4L for the 350h hybrid.

So, how do these compare to the official figures?

Well, quoting the pretty-lax NEDC numbers, the 350 should average 8.7L, the 500h a frankly surprising 6.5L while the 350h shines at just 5.0L in the 2WD and 5.4L for the AWD version.

The corresponding carbon dioxide ratings are 114g/km (RX350h 2WD), 123g/km (350h AWD), 197g/km (350 turbo) and 148g/km (500h).

Technically, then, the most economical RX, the 350h 2WD, can average 1300km per (65L) tank! The 350h AWD can achieve about 1200km, the 500h about 1000km and the 350 turbo just 776km (using a bigger 67.5L tank).

Both RX hybrids can drive silently in electric-only mode stepping off the line, at low speeds or when coasting along, and that's really impressive. Less so is every RX's thirst for more-expensive 95 RON premium unleaded 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.

If you've owned any previous-generation RX, you'll definitely recognise most if not all of their good points, like ease, smooth-road and low-speed refinement, and complete reliability and dependability.

But now the Lexus has gained a far, far broader range of talents and capabilities. And that's a direct result of the series switching to the TNGA platform, like most of its brethren (and Toyota cousins).

Let's begin with the most exciting edition, the flagship RX500h F Sport Performance.

This is the brand's first hybrid turbo, and it's a cracker. Electrified for silky quietness when stepping off the line, the internal combustion engine (ICE) takes over seamlessly as soon as you need to really get moving, providing a rich, torquey shove as required.

While not BMW X5M fast, it's rapid all right, and satisfyingly responsive to your right foot. The whoosh is accompanied by an artificial (albeit quite nice) exhaust note, that's a bit turbine-like, to let you know you are or are about to break the law speeding.

Additionally, wearing 21-inch wheels and tyres, there's an exceptional amount of road grip, for safe, planted handling and roadholding. This applies to all the latest RXs, actually. But – and despite its 100-150kg weight penalty compared to lesser versions ­– the 500h feels the most athletic. Basically, it does what the tin says it should.

The flipside? While the adaptive dampers do smooth out most bumps, it can get a little jittery over some surfaces. And it is prone to some tyre noise intrusion over some bitumen. Yet, compared to former big-wheeled RX, the 500h's ride is comfy enough.

Next up is the RX350. This is basically the 500h with the same four-pot turbo engine but minus the electric motors and battery, so it benefits from a 155kg mass saving. And that's immediately obvious in its better high-speed agility.

However, while the engine loves a rev, the lack of electrification and all that meaty torque it brings is always noticeable, meaning the driver has to always mash the accelerator for overtaking to be over quickly. And as a result, the 350 can sound a bit noisy. Otherwise, for normal commuting and point-to-point travel, this is fine. Unremarkable but supremely capable. You'll miss the hybrid oomph, though. And the economy.

Finally, there's the RX most people buy – the 350h. Yes, there's a RAV4 engine and motor(s) stuffed in haute couture, but this is so much more than that. Performance from a standing start is always brisk, with speed piling on with delightful ease if you so desire, and there always seems to be some muscle left in reserve for instant manoeuvres – whether going fast or slow.

The whole experience is seamless, easy and muted. Only when you floor the throttle does the powertrain whine, but it's not that sort of SUV.

Plus, wearing the 21-inch wheels and with the adaptive dampers, the 350h steers, corners and rides well enough, being both skilful and accomplished, if not especially involving, let alone thrilling.

What we're saying is that the base hybrid proposition is good enough to wear the Lexus badge. The RX has finally come of age, dynamically speaking. And about time.

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 now offers a five-year, unlimited kilometre warranty with roadside assistance.

Furthermore, hybrid versions of the RX include a 10-year, unlimited kilometre battery warranty.

Service intervals are at 12 months or 15,000km, whichever comes first.

The RX offers three years and 45,000km of capped-price servicing, with each one costing owners $695 – that's pretty competitive for a luxury brand.

So is the first-rate ownership experience. Amongst other benefits, there's Lexus' 'Encore' aftersales subscription program; free for the first three years, it includes myriad offers and services including discounted petrol.

Plus, owners can have their cars picked up remotely and returned washed, and with free use of a loan vehicle delivered to their door.

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.