Mercedes-Benz Gls450 vs Audi Q8 E-Tron

What's the difference?

The GLS450d impresses as an entry-level grade, as it’s a more family-friendly allrounder than the specialised AMG and Maybach variants. Its combination of a torque-rich diesel 48V hybrid drivetrain, air-cushioned suspension and plush interior are as well suited to luxury urban travel as they are to grand touring, where its heavy towing and generous load-carrying capabilities can shine. Whether it’s worth around $200K drive-away, only those who shop at the top end of town can decide.

The Audi Q8 e-tron ushers in welcome improvements to an already likeable and capable large luxury SUV.

But it is also feeling dated compared to newer and fresher rivals like the BMW iX, isn’t as good to drive as the best, offers disappointing range for the size of the new battery, and prices are creeping up for what is essentially a half-decade-old EV.

The name change isn’t enough. What the Q8 e-tron really needs is a massive leap in its Vorsprung durch Technik in a rapidly evolving electrified landscape.

 Very good… but far from great.

This is an imposing vehicle in extravagant S-Class tradition, riding on an expansive 3135mm wheelbase and stretching more than 5.2 metres (5215mm) long and more than 2.0 metres (2030mm) wide with a turning circle that's nudging 13 metres.

However, it’s just under 1.8 metres (1798mm) tall, so there’s no clearance issues when accessing multi-storey carparks. And with its side-steps (or ‘running boards’ in nostalgic Benz speak) most adults can step rather than climb aboard, although passengers of shorter stature during our test noted that assist handles on the A and B pillars would be handy.

Central to its sophisticated chassis design is adaptive air suspension, which uses a pneumatic or ‘airbag’ form of springing with adaptive damping to continuously optimise ride comfort and handling response according to road conditions and driving dynamics (see Driving).

The GLS’s styling is clean and uncluttered with tasteful restraint evident in its chrome and satin-chrome highlights, yet it projects a majestic quality with its prominent four-louvre grille and elegantly spoked alloy wheels.

The spacious and sumptuous seven-seat interior is visually pleasing and practical, with a subtle blend of surface treatments, contrasting tones, lots of soft-touch surfaces and exposed stitching. This is combined (thankfully) with physical dials, switches and ‘piano key’ buttons to control numerous interior functions, in preference to distracting touchscreen prompts.

The Q8 e-tron looks smaller than it actually is, with the SUV wagon’s length/width/height/wheelbase numbers measuring in at 4915/1937/1633mm/2928mm, respectively.

The Sportback version is slightly lower at 1619mm.

You’ll need a keen eye to spot the difference between the old e-tron and new Q8 e-tron, with almost all of the visual changes reserved for the front end.

For starters, there’s a new, two-dimensional four-ring logo that looks larger and flatter than before, sitting within a sleeker and slimmer grille treatment that now takes in the restyled headlights. Along with the redesigned bumper, the effect serves to broaden the SUV’s stance.

The effect also suggests improved aerodynamics, aided by small air foils near the wheel arches and a fully-clad underbody section.  

Otherwise, aside from the odd inclusion of the make-model name on the B-pillar and minor trim updates out back, the Q8 e-tron keeps the same, contemporary appearance of its predecessor. Which is no bad thing. 

And there are even fewer changes inside.

Although it has a hefty 2655kg kerb weight, our test vehicle’s 3420kg GVM rating provides a useful 765kg of load capacity, which should comfortably absorb the combined weight of up to seven occupants and light luggage. Or with the third row of seating folded, five occupants and heavier luggage.

It’s also rated to tow up to 3500kg of braked trailer and with its sizeable 6920kg GCM (or how much weight it can legally carry and tow at the same time) it can carry its maximum load while towing its maximum trailer weight.

So, that’s commendable practicality, given it would be well suited to owners that need to tow large caravans, boat trailers, horse floats etc in style without having to compromise much (if at all) on either passenger numbers or luggage capacity.

Driver and front passenger space and comfort is exceptional, as you’d expect. Storage includes a large glovebox plus a bottle holder and bin in each door. The front of the centre console has two USB-C ports, wireless phone charging and heated cupholders, while the rear of the console has a large storage box with a third USB-C port and padded lid that doubles as a comfy elbow rest.

Even tall passengers in the second row of seating enjoy spacious comfort, given I’m 186cm and with the driver’s seat set in my position I have ample knee clearance, foot room and head space.

However, the central passenger must contend with a transmission tunnel in the floor and shoulder room would be squeezy for three large adults, which is okay for short trips but a maximum of two would be ideal for longer journeys.

The rear of the centre console also treats second-row passengers to a pair of USB-C ports, adjustable air-vents and a control panel that allows independent climate adjustment.

There’s also a large bin/bottle holder in each door plus storage nets on each front seat backrest. The centre seat backrest folds flat to allow long items (skis etc) to slot between the outer backrests. And it also serves as a fold-down armrest, containing two cupholders and a lidded slimline compartment that’s ideal for hidden phone storage.

The third row is uncommonly spacious, even for tall people, with padded armrests on each side containing cup holders and twin USB-C ports.

The carpeted rear luggage area has four load-anchorage points, a first aid kit and 12v socket. With the third-row seats upright it offers 355 litres of load volume, which increases to 1350 litres with the third row folded and 2400 litres (or 2.4 cubic metres) with both the second and third rows folded.

More than merely good enough.

Entry and egress are easy thanks to a lofty ride height and wide-opening doors. Once sat, you’ll discover Audi has not changed anything much inside compared to the old e-tron. Frankly, very little needed to.

You’ll still find a strikingly stylish and upmarket cabin offering sufficient space for five people, a commanding driving position, superbly supportive front seats that are a boon when long-distance driving, plenty of storage options, ample ventilation and suitably moody lighting.

While not the most modern dash on the market when contrasted to the vast ‘hyper’ screens of some rivals, the Q8 e-tron’s remains very architectural in appearance and presentation.

Trim and material quality are certainly up to brand expectations. Practicality remains a priority, with lots of storage areas within the dash, console and door cards.

There are no fewer than three screens – a 12.3-inch digital instrument cluster Audi calls 'Virtual Cockpit', a 10.1-inch central multimedia display with haptic feedback and an 8.6-inch unit for climate control.

While they may seem daunting at first, a little familiarisation means most users will find them easy to operate.

Kudos, too, to the super-clear markings in the instrumentation, as well as the very satisfying tactile sensations of using the quality switchgear and controls. Typical Audi thoroughness here.

The same applies to the Q8 e-tron’s roomy and pleasantly-presented back seat area, with intelligently designed seating offering a nicely angled backrest as well as supportive cushion.

Three people can fit across without too much pain, though two is better, as the folding centre armrest and other amenities like air vents and climate control systems can be better-accessed and enjoyed.

You can see, smell and feel where your money’s gone inside. This is a quiet, isolated and cocooning experience, whether cruising on the motorway or stuck in heavy urban traffic. As you’d expect from a luxury SUV.

About the only real jarring aspect are the $3500 virtual exterior mirrors, created to improve aero performance. Their door-mounted screens are set low, outside the natural visual eyeline of the driver, creating confusion and adding precious extra seconds of eyes not on the road ahead. They’re irritating to the point of frustration.

Otherwise, the Q8 e-tron gets the job done inside, with cargo capacity at a reasonable 569 litres in the SUV wagon and 528L in the Sportback. And there’s even a 62L tub in the frunk up front to store the cables that also come standard with the EV.

Audi interior and packaging expertise strikes again.

First thing’s first. The Q8 e-tron has very little in common with the existing Q8 petrol, diesel and SQ8 high-performance models.

These, along with the larger Q7, have internal combustion engines.

However, keep in mind all leverage variations of the same 'MLB Evo' architecture that first saw the light of day all the way back in 2015. So, no spring chickens here.

But as it currently also serves Bentley, Lamborghini and Porsche SUVs, we’re talking about a classy set of components, anyway. Plus, the pre-facelift model was only rolled out on the world market in 2019.

For now, only a single variant is here, known as the Q8 e-tron 55, meaning the previous, smaller-battery 50 and flagship SQ8 aren’t here yet. That will happen sometime during 2024.

As before, there’s the choice of a traditional SUV wagon or more-popular BMW X6-style Sportback SUV coupe.

Prices start at $153,900 (all prices are before on-road costs) for the former and $165,900 for the latter, and that’s a jump of nearly $8K and $9K respectively over their old e-tron-as-a-noun-rather-than-an-adjective predecessors.

At least the Q8 e-tron is well equipped.

On the safety front, you’ll find about 40 driver assistance systems, backed up by a plethora of cameras, radar sensors and ultrasonic sensors to help keep the SUV as secure as possible.

These include a 360-degree camera system, adaptive cruise control, lane-support systems, rear cross-traffic assist and Autonomous Emergency Braking (AEB).

More on safety further down below.

All models also include adaptive air suspension with a variable ride height range of 76mm, a drive-mode selector that switches between normal and sport settings, LED headlights with auto high beams, keyless entry/start, front and rear climate control, heated and powered front seats and adjustable regenerative braking paddles on the steering wheel.

There's also a head-up display, three digital screens including electronic instrumentation and a central touchscreen with haptic feedback, satellite navigation, Android Auto, wireless Apple CarPlay, digital radio, wireless smartphone charging, four USB-C ports, an electric tailgate with gesture control, roof rails and 20-inch alloy wheels – with a space-saver spare wheel to boot.

Plus, an undisclosed number of Launch Edition SUVs from $165,900 are also available, adding Audi’s S line exterior styling touches, 21-inch wheels, sports front seats, a racier steering wheel, electric steering column adjustment and more.

Note that the base Q8 e-tron 55 does not include leather upholstery (it’s synthetic material instead) or a sunroof as standard.

Pricing and spec, then, are generally in-line with the luxury Euro EV SUV competition, which is to say, a bit on the exxy side.

Let’s check out the changes.

The GLS450d comes standard with a 3.0-litre turbocharged inline six-cylinder diesel producing 270kW of power at 4000rpm and 750Nm of torque between 1350-2800rpm.

This is paired with a 48V mild-hybrid system comprising a 48-volt battery (charged by regenerative braking) and an integrated starter-generator which provides both seamless engine stop-start and up to 15kW/200Nm of extra power and torque during acceleration.

A nine-speed torque converter automatic provides the choice of manual shifting using the steering wheel-mounted paddles, along with several selectable drive modes.

The active all-wheel-drive system continuously adjusts the engine’s torque delivery between front and rear axles (and individual wheels as needed) to maintain optimum traction and handling.

Tech-overload alert. As per its predecessor, the Q8 e-tron 55 continues with two electric motors – one on each axle – for ‘quattro’ all-wheel drive.

Upgraded internals are said to improve efficiency substantially. Both are induction/asynchronous motors, mated to a single-gear two-stage ratio planetary transmission.

In the 55 model, the dual-motor set-up delivers a combined 300kW of power and 664Nm of torque, for a healthy 0-100km/h sprint-time of 5.6 seconds, on the way to a 200km/h top speed.

That’s impressive, given the lightest Q8 e-tron 55 tips the scales from 2595kg. That said, the Audi’s power-to-weight ratio is an equally strong 116kg/tonne.

Other updates include more direct steering, stiffer front suspension and retuned chassis controls.

Suspension is a five-link arrangement all-around, with adaptive air suspension featuring an electronically controlled with continuously variable adaptive damping system.

Mercedes-Benz claims official combined consumption of 7.8L/100km and the dash display was showing 9.0 when we stopped to refuel at the completion of our 368km test, which included the usual mix of suburban, city and highway driving with up to five passengers at times and light luggage.

Our own figure, calculated from fuel bowser and tripmeter readings, was close at 9.5 which is outstanding sub-10L/100km economy for such a substantial vehicle in mostly metropolitan use. Therefore, based on our own consumption figure, you could expect a real-world driving range of around 950km from its 90-litre diesel tank.

The good news is that the lithium-ion battery pack size rises from 95kWh to 114kWh, and is accompanied by faster DC charging capability, due to a jump from 150kW to 170kW.

While far from the class best, this cuts down charging times by a considerable margin.

The claimed driving range is 454km, while average consumption is a disappointing 25.6kWh/100km. The Q8 e-tron’s trip computer during our run in it recorded a mid-to-high 20s readout, by the way.

It’s an enjoyable vehicle to drive, with multiple power adjustments for the seat and steering wheel combined with a large left footrest which provide supreme driver comfort and support.

The powerful and responsive turbocharged six-cylinder diesel and nine-speed auto are well suited to this application. The engine’s ample torque provides spirited acceleration from standing starts, taking only six seconds to reach triple-digit speeds.

This drivetrain would be well suited to heavy towing duties, given the 48V mild-hybrid system can contribute an extra 200Nm (in addition to the engine’s 750Nm), which raises the total theoretical torque output to almost 1000Nm.

The active air suspension provides a wonderfully cushioned ride that floats over bumpy roads, while maintaining excellent handling response and surprising agility. These commendable chassis dynamics, combined with the powerful and responsive drivetrain, makes the vehicle feel smaller and lighter than its dimensions and kerb weight would suggest.

Overall, it’s difficult to fault from a driver’s perspective, with the only exception being the voice activation function. This is often triggered by words or phrases other than ‘Hey Mercedes’ resulting in regular interruption of conversations. This needs some fine tuning.

For decades, Audi used the advertising tagline ‘Vorsprung durch Technik’ – which means Progress through Technology in its native German – to highlight how advanced its vehicles are.

So, how has the Q8 e-tron advanced over its predecessor?

Right from the get-go, there’s so much to dig about the electric Audi SUV, especially if you’re new to luxury EVs.

To start with, it’s as quiet as you’d expect, even by luxury brand standards. As the Audi accelerates, the sense of momentum is somewhat masked by how refined and civilised your progress is.

Watch that, though. You could get a speeding fine more easily than you expect!

Anyway, with 664Nm of torque coming on instantly, there’s certainly no shortage of it, backed up by enough muscle for effortless and instantaneous overtaking. This sort of motoring can become highly addictive.

Similarly, a low centre of gravity, combined with a beautifully modulated electric power steering and the quattro AWD set-up, provides pleasing agility combined with reassuring roadholding. Even when you’re pressing on, the Q8 e-tron corners and grip with confidence and control.

So far, so good. Especially considering the air suspension is further cushioning your sense of speed, with excellent bump absorption for an isolated ride.

That’s on the standard 20-inch alloys spec. Riding on the larger wheels, there is a bit more firmness, as well as some road-noise intrusion.

Plus, it doesn’t take long to realise the Q8 e-tron is a very heavy vehicle. Though undeniably quick and athletic, changing directions in a hurry means that the SUV can feel a bit unwieldy.

Throttle response at higher velocities can seem a little muted and, over certain crests and humps when travelling fast, there is a sense that the driver really needs to have their wits about them.

Best to take it a bit easier, then, and enjoy the serenity the Audi EV SUV delivers in more typical and restrained travelling scenarios.

There is so much that the Q8 e-tron brings, and driving it normally really does reveal a sophisticated, comfortable, dependable and high-quality grand-touring experience.

Push a bit harder, though, and some cracks show up.

Tested way back in 2019 but updated in September, 2023, the e-tron/Q8 e-tron range scored a maximum five-star ANCAP crash-test rating.

There is no shortage of safety equipment – with passive and active, driver-assist-heavy technologies designed to avoid an accident, with full surround-view cameras also providing an extra level of security.

Standard kit includes Audi’s 'Pre-Sense front' and 'Pre-Sense rear', offering AEB, cross-traffic alert and active lane-keep assistance tech, as well as adaptive cruise control with full stop/go, eight airbags (dual front as well as side and curtain airbags for all outboard occupants), hill-descent control, anti-lock brakes, electronic brake-force distribution, brake-assist, electronic stability control, traction control and tyre pressure monitors.

The AEB system can detect pedestrians and cyclists between 10km/h and 85km/h, and even at night, while for other motor vehicles that increases to 250km/h (an upper velocity more relevant for the coming SQ8 e-tron). The active lane warning operations is from 65-250km/h.

Both outboard rear seats feature ISOFIX child-seat latches, along with three top tethers for straps.

The GLS comes with a five-years/unlimited km warranty (better than BMW and Lexus) and five years of roadside assistance. Scheduled servicing is every 12 months/25,000km whichever occurs first.

Mercedes-Benz offers capped-price pre-paid servicing packages with three, four or five-year terms. For example, the total upfront cost of the minimum three-year term is $4090, or an average of $1363 per service.

Audi provides a five-year/unlimited kilometre warranty as well as six-years’ worth of free roadside assistance, which is nothing unusual these days, while the battery warranty is eight years or 160,000km.

The first six years of scheduled servicing is free, too. Intervals are every two years/30,000km (whichever comes first).

Plus, owners also receive six years of complimentary access to Chargefox’s network.