Mercedes-Benz S450 vs Audi Q8

What's the difference?

Mercedes-Benz set out to restore the S-Class' place amongst the greatest sedans in the world.

In the heavily-optioned, near-$250K-plus S450 as well as the extended S450L at $300K as tested (the sweet spot of the range for now), we reckon the Germans have succeeded, pushing safety, comfort and technology boundaries, in a package that is true to the heritage of the series.

Tax-fuelled sky-high prices will certainly keep the S-Class niche in Australia, but the car is more than good enough to dominate its tiny corner of the upper-large luxury car sphere.

The best new car in the world? We reckon it's highly likely. Mission accomplished, Mercedes.

The updated Audi Q8 60 TFSIe quattro S line still looks good inside and out. It fits a family comfortably without feeling too big and there’s enough here to satisfy those who like the luxury features. 

It's price tag will hurt it but the improved power outputs and driving range is a big plus and makes the plug-in hybrid powertrain make more sense.

Most Mercedes models have followed the Russian Doll-style cookie-cutter styling theme, and the heavy family look continues with the W223.

Still, the flush door handles do add a touch of Tesla-esque modernity, while the elegant silhouette and clean lines are in keeping with the luxury aspirations. Larger in every dimension compared to the old W222, the S450 is some 71mm-longer in wheelbase (3106mm) than before while the LWB's has stretched out by 51mm (3216mm), benefiting proportions as well as interior packaging.

AMG-branded wheels look sporty but – in the S450 at least – they're perhaps a tad too gangster. A set of flush alloys would give it a more-modern and techier appearance, in our opinion.

Overall, however, the S-Class ‘7' possesses the prerequisite richness of design. It isn't as bold and mould-breaking as models like the W116 were back in their day, but the styling is still a success.

By the way, the latest S-Class is the first Mercedes to employ the MRA2 longitudinal platform, which is rich in lightweight steels (50 per cent aluminium), is correspondingly stronger than before but also 60kg lighter.

With a drag co-efficiency rating as low as 0.22Cd on some overseas grades, the W223 is one of the most aerodynamic production vehicles in history.

When it comes to style, the Q8 60 TFSIe quattro S line has it in spades. Featuring a design that looks athletic with its long lines and wide stance, you'll always be proud to hop into it.

Red calipers now come standard and they look awesome on the optioned 22-inch alloys. The update sees a redesigned front with new grille and reshaped matrix LED headlights and a 2D badge design.

While SUV coupes aren’t usually my jam, the Q8 manages to tick the 'sexy' box.

The interior is honestly the same and only die-hard fans will notice the new menu screens on the multimedia system. The cabin is a fine example of what a luxury SUV should look like because its polished, well-built and sumptuous but it has the classic Audi edge, so there is still a sporty vibe going on.

The panoramic sunroof adds some airiness to the otherwise dark cabin and the Valcona leather upholstery is liberally splashed about, so most of what you touch feels premium and soft.

For the beginning of our day with the S-Class, we were chauffeured from home to a mansion in Kew, a blue-chip Melbourne suburb. Our heavily-optioned S450L featured most of the aforementioned extras – including the Business Class Package and Rear Entertainment Package – and the experience was predictably, sumptuously memorable.

Reclining individual rear seats with easy-reach tablets, armrests offering access to all multimedia and available climatised and massaging cushions and backrests... we're no longer in our normal ride, Toto.

Yet, all these trinkets and gizmos are mere add-ons, that can turn a stretched Caprice into a flash hen's night carriage if enough money and glitz is thrown at it.

No, the new S-Class must impress in an altogether less tangible and more philosophical manner, involving all the senses, and not just what we see, hear and touch. It must appeal beyond the superficial. Otherwise, it is not a large Mercedes-Benz luxury sedan in the classic manner.

This is a Herculean task for the Stuttgart designers and engineers. By and large, though, the Three-Pointed Star has succeeded in achieving something special.

In its perception of peerless quality and engineering, the W223 is striving to move forward and look back simultaneously to the glory days of the seminal W126 (1980-1991). This is through meshing traditional virtues like solidity and quality materials while dazzling its passengers with technology that is still friendly enough to want to enhance your experience.

You can sink into the soft lounge seats, watch the world pass by silently outside and never be aware of the road underneath or the engine ahead. Double glazing, exquisite and aromatic fabrics and materials and lush tactile surfaces work their magic inside the car, while an airtight and aero body, solid platform, air suspension and a muted yet muscular powertrain all do their thing underneath. The atmosphere is special and rarefied. That's what an S-Class needs to be and that's what is happening in our $299,000 (as tested) S450L.

The same more-or-less applies up front, as the same trim, leather, wood and technology surrounds the driver and passenger. The spectre of the car that is surely The Car of the Last Decade – Tesla's Model S – is evident in the portrait touchscreen and sparse, almost wallflower dashboard design and layout. No big imposing architectures here.

Yet, while the American upstart actually takes stuff away, the S-Class packs the cabin with subtle features that – like when the planes stopped flying last year and the birdsong subsequently returned – only become obvious once the cabin's design simplicity clears all the white noise for you to be in a better frame of mind to enjoy them.   

Take the haptic interface, for example, as it is perhaps the best we've experienced; the sense of well-being garnered from the cumulative effects of profound seat comfort (the massaging function was never switched off), cocooning micro climate environmental control, orchestral levels of audio entertainment and the theatre of light and vision performed by the two available screens; it is an automotive experience like no other. And the eye-tracking 3D-effect navigation set within the electronic instrumentation. No need for cinematic glasses to get the effect. The driving position itself, by the way, is also first class.

Room to stretch and grow for sure, and in every direction. But room for improvement? You betcha.

Your tester had a headache after a little while staring at that woozy 3D map. The central vents – four at the front, two in the rear – look and feel cheap, leaving us mentally redesigning them; they are frightfully out of place here; the carryover column-stalk auto lever should have been binned in 2005. And, even though the digital instruments have a number of options, none are elegant enough for the S-Class. That's an especially subjective criticism, clearly, but one that – in the context of classic Mercedes luxury sedan contenders – is justified given how timeless the Bruno Sacco era of Daimler design was. Look him up, kids.

Still, after a couple of hours behind the wheel, with our senses reset to calm, it is obvious that the S-Class cabin is a unique and wonderful place – as it should be at a cool quarter-of-a-million dollars.

Job done.

PS At 550 litres (20L more than before), the boot is massive and luxurious enough to sleep in.

The cabin offers plenty of space for passengers and you never feel like you're jostling for elbow room unless there's three adults across the rear seat. Comfort is high with ergonomic seating up front with plenty of adjustment and functions. The rear seat has long bases and the seat backs can recline.

Individual storage leaves a little to be desired for the class and the glove box shoulders most of the burden up front as the middle console is really just a shallow shelf large enough for a wireless charging pad and keys or a chapstick.

Each row gets a couple of cupholders and drink holders, and the rear map pockets round out back-seat storage.

Because of the PHEV powertrain, the 60 TFSIe quattro S line has the smallest boot capacity in the line-up at 505L but this is still more than enough for a decent road trip or grocery haul.

The wide boot aperture, level loading area and powered tailgate add some convenience, as does the 40/20/40 split fold on the rear seats.

Access for each row is solid with wide door openings, low seat positions and 205mm ground clearance. Although, the doors have to been slammed shut for them to close properly and this annoyed everyone in the family. You can spring for a soft-close door feature for $1500 and, honestly, it would be worth it.

The 10.1-inch touchscreen multimedia system is logically laid out and the graphics look great. It has haptic feedback which my husband didn’t love as it made it hard to select things on a bumpy road. You also get built-in sat nav, wireless Apple CarPlay and Android Auto. Other than the occasional lag with the CarPlay connecting upon start up, it's all simple enough to use.

Charging options are good with two USB-C ports in each row and the front also gets a wireless charging pad. The big 12.3-inch digital instrument cluster looks great but it can be annoying to find information on it or personalise it.

There are three Q8 grades before you hop into the flagship SQ8 performance model, and the variant on test for this review sits second from the top.

The mid-life refresh sees pricing increased across the entire range and adds over $1700 to the (already steep) $154,284 MSRP price tag.

Compared to its plug-in hybrid rivals, the BMW X5 xDrive50e and Volvo XC90 Recharge Ultra T8, the 60 TFSIe quattro S line slides in as the most expensive.

Our test vehicle has also been fitted with a few extra items like 22-inch alloys, metallic paint and a luxury seat package, which adds ventilation function to the front seats and heated rear outboard seats. It does tack on $9900 to the overall price tag, though.

The 10.1-inch multimedia system remains and while it sits on the smaller end compared to some of its rivals now, it does get an updated layout and apps for 2025.

Other standard equipment includes a panoramic sunroof, matrix LED headlights, heated side mirrors with memory, keyless entry and start, a powered tailgate, heated front seats, electric lumbar support, three-zone climate control, electrically adjustable steering wheel, electric auto cargo cover, and a tyre repair kit.

The technology is the standout with a 17-speaker Bang & Olufsen sound system, wireless Apple CarPlay and Android Auto, digital radio, as well as built-in satellite navigation, a 12.3-inch digital instrument cluster and colour head-up display.

You also get an Audi Connect plus app which allows remote access for security and assistance services including car finder with remote signal, remote lock and unlock, emergency call, and online roadside assistance.

Does the PHEV Q8 offer good value? Value is relative, the features list is fairly robust but it’s hard to ignore that this PHEV sits $10K above its internal combustion siblings.

Where are the V8s?

Right now, the only W223 you can buy is powered by an all-new 2999cc 3.0-litre in-line direct-injection six-cylinder turbo petrol engine dubbed the M256, complete with double overhead cams, an electric compressor intercooler and assistance from a 48-volt mild hybrid system and integrated starter-generator, adding 16kW and 250Nm to the 270kW of power at 6100rpm and 500Nm of torque from 1600-4500rpm.

The 9G-Tronic torque-converter automatic transmission and 4Matic all-wheel drive system combination is a first for the S-Class in Australia.

Top speed is limited to 250km/h, while the 0-100km/h sprint-time takes just 5.1 seconds in both models. Impressive for a two-tonne-plus luxury limo.

The Q8 60 TFSI e is AWD and has a 3.0-litre V6 turbo-petrol plug-in hybrid powertrain for a combined power output of 360kW and 700Nm of torque.

The power output has increased by 20kW with the mid-life refresh and that shaves 0.4 seconds off the 0-100km/h sprint time bringing it down to just 5.0 seconds. So it’s a quick and powerful SUV.

The powertrain is paired with an eight-speed automatic transmission which is mostly smooth and the switch between petrol and electric is fairly seamless.

As far as plug-in hybrids go, everything seems to work well here.

With the aid of the mild-hybrid system, the S450 returned a combined average of an impressive 8.2 litres per 100km, which translates to 187 grams of carbon dioxide emissions per kilometre. 95 RON premium unleaded (or higher) is recommended. In the urban run it consumes 11.3L/100km (11.5 for S450L), and just 6.4L/100km (6.5 for S450L) in the extra-urban result.

At 76 litres, the fuel tank will allow a combined average range of about 927km between refills.

The mid-life update sees a larger 25.9kWh lithium-ion battery which improves the electric driving range by 27km, bringing it up to 74km overall. This still falls short of its direct rivals but it’s an improvement for efficiency because it’s now more than enough range if you’re just doing the school runs and some errands around town.

The Q8 60 TFSIe has a Type 2 charging port and like most plug-in hybrids, lacks a CCS enhancement, so you have to make do with AC charging options with this one. On a 7.4kW AC charging system you can go from 0-100 per cent in three hours and 45 minutes but if you’re using just a standard house plug port, it will take a few hours more. It's best to leave it overnight.

Audi throws in three charging cables, including a 240-volt domestic charger but you have to pay extra for a wall-mounted box.

The official combined fuel cycle is a low 1.8L/100km and like all plug-ins the best efficiency will be achieved if you charge it often. After charging almost every day and doing a mix of open road and urban driving, my real-world usage has popped out at 7.7L/100km, which isn’t as good as I was hoping but it’s not terrible. I would expect the efficiency to drop on longer trips.

The Q8 likes to drink the good stuff and Audi recommends a minimum 95 RON unleaded petrol to be used for this grade.

In former times, as the Germans say, a ‘450' on the boot indicated V8 power. In the W116 S-Class era it was one of the world's most evocative badges when ‘SEL' was also attached.

As mentioned earlier, though, it's the M256 3.0-litre turbo-petrol with a 48-volt ‘mild hybrid' electrical system that's doing the driving, to all four wheels. The real V8 W223 will probably surface later this year or in early 2022 with the S580L flagship. Bring it on.

This is not to say that S450 isn't good enough. With that electrified assistance, the blown straight six is smooth and swift off the line and rapid as the auto seamlessly steps up through all nine gears. Because it's so hushed and refined, it doesn't feel 5.1s to 100 clicks quick, but watching the speedo says otherwise – acceleration is assertive and strong right up way past the legal speed limit.

All that's missing is the burbling soundtrack of a classic Benz bent-eight. Oh well. Outstanding economy is a price we're literally willing to pay in lieu.

Even more impressive is the S450's ability to hustle along mountain roads like an overgrown sports sedan.

Now, for Australia, all S-Classes are fitted standard with an adaptive ‘Airmatic' air-suspension set-up, including air springs and self-levelling tech. In Comfort up to 60km/h, the ride height can be raised by 30mm, or lowered by 10mm under the standard 130mm baseline in Sport at any velocity, while in Sport+ it falls another 17mm.

With that in mind, yes, the standard air suspension performs a magnificent job smothering out most surface imperfections around town. Yet its real other party trick is to tighten up the chassis when corners get interesting and Sport mode is selected. Aided by progressively weighted and reassuringly responsive steering, the Mercedes tips into turns with precision and poise, slicing through with virtually no discernible body lean or understeer.

Now, we're not talking a leisurely drive on rural highways here, but Healesville's famous Chum Creek Road, where even a Porsche Cayman would feel like it's had a strenuous dynamic workout. The S-Class can be hurried along with confidence and finesse, displaying outstanding handling and roadholding for a 5.2-metre long limo. And the fact that the ride quality only suffers marginally when the red horns are out is all the more remarkable.

Back in the cut-and-thrust of inner-city peak-hour traffic, the Benz in Comfort mode continued to reveal its driver-orientated yet passenger-focused twin-personalities, zipping in and out of gaps while remaining comfy and composed inside.

Only when parking in tight spots are you truly aware that the W223 is longer than a Mazda CX-9. The optional four-wheel-steering system is claimed to slash the turning circle to A-Class hatchback levels. 10.9 metres is the claim.

The 2021 S-Class never ceases to amaze and delight.

The Q8's athletic looks are matched by its on-road handling. The power has a hefty kick that’s effortlessly delivered once you’re up to speed. It did have a few confused moments when I had to accelerate quickly from a full stop - the lower gears didn’t immediately engage and I got a proper bunny hop but it was short lived and for the most part the powertrain delivers the goods.

The adaptive air suspension makes for a comfortable ride despite the massive wheels and you can comfortably cruise around town or the highway without much jostling.

Cabin noise is minimal around town but you get a low hum of road noise at higher speeds. Overall, it's still a refined cabin space to spend a lot of time in.

I do miss hearing some of the engine thrums though because even when the battery is depleted, you don’t get a lot of engine feedback. It certainly adds to the refinement but it loses some of the fun.

The higher driving position feels comfortable and visibility is quite good. Steering is responsive and feels sporty with lane changes but its 13.3m turning circle lets it down in car parks.

The 360-degree view camera system is clear and this has multiple parking sensors. In theory parking should be easy but again, until you get used to that bigger turning circle it can feel clumsy in smaller spaces.

The PHEV Q8 variant is unrated with ANCAP as it’s not covered by it’s siblings' five-star rating from 2019, but it does have a lot of standard safety features like eight airbags, including side chest airbags for the front and rear passengers. Surprisingly, it misses out on a front centre airbag though. 

A standout feature is the safe exit assist which will delay your door from opening if it detects a car or cyclist. Always a handy thing when you have a kid like mine who can carelessly throw open their door.

There is also a ‘pre-sense’ feature where the car detects that you’re approaching traffic at lights or a roundabout and it will automatically start slowing down for you, which I quite liked.

Other standard features include adaptive cruise control with stop and go, lane keeping aid, lane departure warning, blind-spot monitoring, forward collision warning, rear cross-traffic alert, driver attention monitoring (sound and visual alerts), 360-degree view camera system, front and rear parking sensors, tyre pressure loss indicator, intelligent seatbelt reminders, first aid kit, hi-vis vests and a collapsible warning triangle.

The autonomous emergency braking (AEB) has car, cyclist and pedestrian detection and is operational up to 85km/h (up to 250km/h for cars).

There are two ISOFIX child seat mounts and three top tether anchor points. The rear seat is wide enough to accommodate three child seats side by side.

The safety systems feel well-calibrated and are not intrusive for daily driving. In a world when cars seem to chime an alert for everything, this is a welcomed plus.

Unlike many luxury brands that persist with a sub-par three-year warranty, Mercedes-Benz offers a five-year/unlimited kilometre warranty.

Intervals are every year or 25,000km, with a capped price service plan starting at $800 for the first year, $1200 for the second year and $1400 for the third year, totalling $3400. Alternatively, there is a Service Plan starting at $2700 for the first three years (saving $700 from the normal capped-price service plan), $3600 for four years and $5400 for five years.

Audi offers the Q8 60 TFSIe with a five-year/unlimited kilometre warranty and the battery is covered by an eight-year/160,000km warranty which are all pretty standard terms compared to its rivals.

There is a standard five-year servicing package that costs $3570 and servicing intervals are spaced at every 12 months or 15,000km, whichever occurs first. However, if you purchase the Audi Advantage Package you add a further two years of coverage to the warranty, roadside assistance and servicing, which is pretty good for the class.