Mercedes-Benz S400 vs Audi SQ8

What's the difference?

The 2018 Mercedes-Benz S-Class remains a technological tour de force, a luxury sedan to be reckoned with - one that has safety, technology, comfort, finesse and performance all rolled into a stylish package. 

It's hard to see why you'd need anything more than the S 350 d, which is now much more attractively priced. It'd be my pick, but I'd have to get the Energizing Comfort Control package, and probably the AMG styling pack, too. And even then it would cost less than its predecessor.

The Audi SQ8 isn’t your typical performance SUV. It’s more refined and less flashy. The tech can be more complicated than it needs to be and if you’re wanting that V8 soundscape, you won’t find it here.

However, the handling and on road experience are superb plus you can comfortably haul the family around and look good doing it.

I swear it has been facelifted, and the changes are bigger than they might appear. There is no doubt that the S-Class shape is largely unchanged, but the German company has kept the modifications minimal in the scheme of things.

That doesn’t mean those changes are unnecessary, though. The new headlights, for example, are standard on every model, and are constructed with 84 LEDs (including three for the daytime running lights), and of course they’re adaptive with automated high-beam - meaning they’ll shield other road users from the glare of the lights at night. And the lights themselves will throw a main beam up to 650 metres, according to the company. 

Other things are slightly more cosmetic, like the revised three-bar grille treatment, new front and rear bumper designs that feature broader sculpted sections to widen the stance of the car, and there are new LED tail-lights as well.

The smallest set of wheels used to consist of 18-inch rims, but now the base car rolls on 19s, while the rest of the expansive range sits on 20s. 

The inside has seen some changes, too, but the appearance of things in the cabin isn’t the focal point - its the usability of the technology that's the big change. 

Oh, but I should tell you there are now 64 ambient lighting colours to choose from, which is up from seven, and now you can also set the lighting in three different zones - so theoretically you can have blue, orange and green areas of the cockpit, if you’re gross.

The SQ8 is a gorgeous coupe-style SUV that looks purposeful and poised with its balanced proportions and wide stance. It’s stands apart from its siblings thanks to the S-styled nose treatment and our test model's black accent package makes the honeycomb grille look even sportier. 

The update sees new air intake vents at the front, matrix LED headlights and new chrome exhaust tailpipes.

The upgraded 23-inch alloys with red calipers behind them hint at what’s under the bonnet, as does the Sakhir (sack-heer) Gold paintwork which is aptly named after the one-off Grand Prix race circuit.

The interior looks luxuriously appointed with the black Valcona leather upholstery and the dash is headlined by three high-end technology screens. The SQ8 also gets sport seats featuring a quilted design and 'S' badging but there’s not much else separating it from its siblings.

Audi fans will love the the SQ8's more understated interior but newcomers might be surprised it's not as flashy as some of its rivals.

If you’re buying a Mercedes-Benz S-Class there’s a good chance you’re more interested in the back seat than the front: you could be buying it for a business, or you could like to be driven around - and there are definitely worse places you could be.

We would suggest, though, that the best place you could be if that’s your caper is in the back of a long-wheelbase S-Class model, which has extra legroom. 

And if you happen to be in a LWB model with the 'Business Class Package', you’ll enjoy two individual rear seats rather than a three-seat bench, folding tables for your bento box or laptop, and an ‘executive seat’ on the passenger side that features a foot rest and allows you to slide the front seat forward to liberate more room. Deluxe. 

No matter if you are in one of the stretched models demarcated as such by the ‘L’ suffix or not, you will enjoy excellent seat comfort and good head- and shoulder-room. Legroom in the regular models isn’t as plentiful as you might expect: much more affordable cars like the Hyundai Sonata give the S-Class a run for its money in that regard.

There are good storage options for odds and ends, with the back seat featuring a fold-down armrest with pop-out cupholders and a storage box, as well as map pockets - and the boot space varies depending on the model, but the S 350 d has a 510-litre cargo capacity (VDA). All four doors have bottle holsters, and a bit of extra room besides. Of course there are rear-seat air-vents, and if you’re kids are lucky enough to ride around in a S-Class, the two ISOFIX/three top-tether points will be welcome.

Up front there are two cupholders between the seats, and a new wireless phone charger in the centre console (Qi compatible phones only). There are two USB ports as standard in most models, while models with the rear seat entertainment package fitted get rear USBs. 

The huge screen that runs across two-thirds of the dashboard has seen the noticeable join marker removed for this update, with the monitors being upgraded to a higher resolution and the graphics have been reworked, too. The codpiece-style controller of the Comand media interface remains, and while it still isn’t as simple as other controllers, it is reasonably easy to get used to. 

So … what about Beyonce? 

She comes in as part of the Energizing Comfort Control system, which is standard in some models and a $1400 option in those that don’t have it fitted. 

Essentially it allows you to choose between different set moods: 'Joy', 'Freshness', 'Vitality', 'Warmth', 'Comfort' and 'Training', the latter of which offers three different stretching/exercise programs that last for 10 minutes to stop fatigue. The instructions are given by voice over the sound system.

Each of the moods will adjust the temperature and ventilation (the Freshness setting offers ‘gusts’ of fresh air as if you’re at the beach!), ambient lighting, air fragrance and intensity, and the massage function for the seats. And the music bit - there are predefined songs the system can cue up to suit the mood, or it can identify songs on a hard-drive or USB that suit the programs by analysing the tempo of the tune. Amazing, right?

The new steering wheel looks a lot sportier than the one in the pre-update car, and it has finally done away with the awkward cruise control stalk in favour of steering wheel buttons for the adaptive cruise control system.

The upper large SUV tag certainly makes sense when it comes to cabin space because there's a lot of it. Both rows enjoy ample head- and legroom and access is great thanks to wide door apertures and high ground clearance.

Comfort is high with well-padded seats and thanks to the Sensory Package all but the middle back seater get some luxury extras.

The centre rear position has compromised legroom courtesy of the transmission tunnel, so it's best for a kid. However, the front seats take the cake with their massage, heat and cooling functions and adjustable supports.

Amenities are great throughout the car and the extendable sun visors, rear electric sunshades, soft-close doors and four-zone climate control clinch the practicality deal.

Individual storage is a bit sparse up front with two cupholders, a drink bottle holder in each door and a shallow middle console that realistically only fits a phone.

The glove box is a great size. I can fit my handbag in it, but there are not a lot of areas to pop your smaller items in.

Individual storage is a bit better in the rear as you get two big map pockets, a drink bottle holder in each door, plus two cupholders in the fold-down armrest - so it feels like you have more places for your bits and pieces.

Technology looks amazing but overwhelming to use until you wrap your head around it all. The haptic feedback also gets tired fast. The built-in satellite navigation is super simple while the head-up display and digital instrument cluster feature pull through directions, which is handy.

Charging options are good with each row getting two USB-C ports and a 12-volt socket but the front also enjoys a wireless charging pad. The pad is slow to charge, though, and left my iPhone feeling super hot whenever it was used.

The boot is a good size at 605L and easy to access, too. The sloping roof means larger items have to sit flush with the seats but you shouldn’t have to worry for road trips. 

The back seat has a 40/20/40 split which opens up storage options and this model has a powered tailgate.

There are three fuel-based variants for the Q8 and the model on test is the top-spec SQ8 TFSI quattro. Its mid-life refresh has seen a price hike of $10,015, bringing it's before on-road costs price to $178,815.

Our test vehicle has also been fitted with a few extras, like a 'Sensory Package' ($14,400) which includes a black headliner, upgraded 23-speaker Bang & Olufsen 3D surround sound system, massage function for the front seats, heat function for the rear outboard seats, electric sunshades for the rear row and an air-quality perfume function.

Also fitted are various black and matt carbon accents across/inside the body for a total of $5400, optioned 23-inch alloy wheels ($3000) and specialised 'Sakhir Gold Metallic' paintwork for $1600. Which brings the total MSRP price tag to $203,215.

Even with all of these extras, the SQ8 is still the most affordable performance SUV compared to its nearest rivals as the Porsche Cayenne GTS starts from $212,600 MSRP and the Mercedes-AMG GLE 63 outstrips them both at $272,300 MSRP.

As you'd expect the standard features list is robust for the SQ8 and includes premium features like a panoramic sunroof, electric front seats with heating/cooling and memory functions, full-leather upholstery, soft-close doors and a heated steering wheel.

There is a bunch of high-end technology throughout which includes a colour head-up display, 10.1-inch touchscreen multimedia system, 8.6-inch climate control panel, 12.3-inch digital instrument cluster, satellite navigation, wired/wireless Apple CarPlay and Android Auto, digital radio, four USB-C ports, three 12-volt sockets and a wireless charging pad.

Practical features include keyless entry and start, rain-sensing windscreen wipers, dusk-sensing LED headlights, a powered tailgate, adaptive air-suspension and four-zone climate control.

Overall, not a bad list of features for this part of the market and you won't be left wanting.

The big news for the majority of S-Class buyers is the new engine in the S 350d, which is a 2.9-litre in-line six-cylinder turbo-diesel with 210kW of power and 600Nm of torque. It has a nine-speed automatic and is rear-wheel drive (RWD).

That same diesel engine is wicked up in the S 400d L, with that model churning out 250kW and 700Nm, and remains rear-drive with a nine-speed auto.

The petrol model range is opened by the S 450 L with a 3.0-litre six-cylinder twin-turbo mill producing 270kW/520Nm. Again, nine-speed auto, RWD.

The S 560 and S 560L run the same 4.0-litre twin-turbo V8 petrol with 345kW of power and 700Nm of torque. Nine-speed auto, rear-drive - naturally!

The AMG-fettled S 63 has a thumping twin-turbo 4.0-litre V8 petrol engine with 450kW and 900Nm, with a nine-speed MCT multi-clutch auto and - you guessed it - RWD.

Our test vehicle has a 4.0-litre, twin-turbo petrol V8 engine that produces 373kW and 770Nm. That means it sits in the middle of its rivals in terms of outputs with the Mercedes being top-dog with its 450kW/850Nm combo.

Still... the SQ8 is no dainty flower when it comes to power delivery and has an impressive 0-100km/h sprint time of just 4.1 seconds. 

The SQ8 is a full-time all-wheel drive with an eight-speed auto transmission and the whole engine combo delivers a powerful but elegant on-road experience.

The diesel models are - unsurprisingly - the most frugal in the range, with the entry-level S 350 d using a claimed 5.4 litres per 100km across a range of disciplines.

The S 400 d L - which uses a higher-output version of the same diesel drivetrain as the model above - uses only a minuscule amount more: its claim is 5.5L/100km. 

The most frugal of the petrols is the S 450 L, with its six-pot petrol twin-turbo using a claimed 8.4L/100km.

Every model has stop-start - including the AMG - and the V8 petrols also feature cylinder deactivation when in 'Eco' mode.

That cylinder deactivation system helps the S 560 achieve an incredibly low claimed consumption of 8.5L/100km. So does the longer, slightly heavier S 560 L.

The higher-out Mercedes-AMG S 63 L uses 9.0L/100km, according to its claim. Amazing for the outputs of the engine.

The official combined (urban/extra-urban) fuel cycle figure is 11.9L/100km, which is lower than its rivals.

My real world usage sits at 12.3L/100km after a mix of open-road and urban driving.

This result is decent for a performance SUV but expect it to be thirsty in an urban environment as the on-board gauge hit the mid-20s in the city.

Based on the large 85L fuel tank theoretical driving range is 714km and around 690 using our real-world result. Respectable for a performance SUV but not as good as some family SUVs.

Smooth. It wasn’t even because I’d chosen the Energizing Comfort Control mood to elicit that vibe. It’s smooth - and so it should be.

Whether it’s the near-silent new six-cylinder diesel, which hauls the near two-tonne sedan along with less fuss than a medical centre receptionist dealing with a room full of coughing patients. There is no fuss. You just hand over control to the engine, and trust it will get you where you need to be.

The V8 petrol in the S 560 also has a bit of a silent killer vibe to it. There’s perhaps not as much noise as a V8 fan might want, but the mumbo is there, and in both cars the gearshifts are sublimely timed and super smooth.

Admittedly, the stiff-sided run-flat tyres on both the 19- and 20-inch wheels can exhibit a slight terseness over sharp edges, but when it comes to rolling over pockmarked surfaces or rougher country backroads, the ride offered up by the air suspension with variable dampers is superb. Put it in Sport mode and it stiffens up to the degree you’d expect, but Comfort is no doubt the best place to be.

The steering is super light but accurate, meaning it’s easier than you’d think to pilot this behemoth of a sedan through corners. The grip on offer is excellent, too, even if traction can be an issue - I had a full couple of seconds of strobe light action from the traction control light when I buried the throttle in the S 560. 

I didn’t get a chance to drive the six-cylinder petrol S 450 L, or the S 400 d L. And, I’m really sad to report, there was no opportunity to drive the AMG S 63 L, either. 

But the overall feeling of the updated range is that it remains a deluxe and delightful limousine - whether you have the good fortune of being in the driver’s seat or not.

The SQ8 delivers on power because it’s effortless to get up to speed and the pick up is super responsive when the start/stop function is turned off (otherwise there can be some lag).

The engine doesn’t sound like a big and grumbly V8, though. There are some growls but it’s mainly when you turn the engine on and not to be obnoxious about it but if you're in a V8, you want to hear it as it’s part of the fun of having a big bruiser engine like this!

What doesn’t help the V8 soundscape is the fact the cabin sounds like a noise-cancelling headphone inside. There is a small hum from road noise but it’s pretty darn quiet. Almost EV quiet at times but that means the driving experience leans more towards refined and elegant rather than sporty and fun. 

The SQ8's handling is great - super direct steering, stable in corners and well-rounded passenger comfort when it comes to suspension.

You still get road feedback, which I like as a driver, but it’s not too stiff thanks to the adaptive suspension.

The SQ8 is a large car but you wouldn’t know it when it comes to parking. The 360-degree view camera is clear and the dynamic guidelines help you to position this big unit even the smallest of car parks.

The SQ8 has a maximum five-star ANCAP safety rating from testing done in 2019 and features eight airbags, including side chest airbags for both rows. It's common to only find the latter in the front – so that’s great for a family car.

The SQ8 scored well across its ANCAP individual protection segments, scoring 93 per cent for adult occupant, 88 per cent for child occupant, 71 per cent for vulnerable road user and 75 per cent for its safety assist.

The SQ8 has a long list of safety features including blind-spot monitoring, safe exit warning, driver attention monitor, fatigue reminder, matrix LED lights, SOS call, forward collision warning, rear collision warning, rear cross-traffic alert, lane keeping/departure aids, tyre pressure monitoring, adaptive cruise control (with stop & go and lane keeping), park assist and a 360-degree reversing camera plus front and rear parking sensors.

The rear row features two ISOFIX child seat mounts and three top tether anchors.

The SQ8 has AEB with car, pedestrian, and cyclist detection and is operational from 10 – 250km/h but it is usual to see this system operate from as low as 4.0km/h.

Mercedes-Benz offers a standard three-year/unlimited kilometre warranty.

Servicing is due every 12 months or 25,000km on all engines except AMG drivetrains, which require servicing every year or 20,000km. 

Mercedes-Benz has a (pricey!) capped-price servicing plan. The standard diesel and petrol models in the S-Class range cost $596 for the first service, and $1192 for the second and third visits. The costs for the sole AMG model is $736 for the first service, then the second and third visits are $1472 per.

The SQ8 comes with a five-year/unlimited km warranty, which is a normal term for the class.

It also comes with capped servicing for five years or up to 75,000km and averages $920 per service, which is very good for the segment.

Servicing intervals are reasonable at every 12-months or 15,000km, whichever occurs first.