Mercedes-Benz S400 vs BYD Sealion 8

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.

There’s no denying the value the BYD Sealion 8 Premium offers as it packs a lot in for the price. Its efficiency and inoffensive looks add up to a good package and reflect what it does well. That said, the underwhelming driving experience and clunky media system are noticeable. Whether they're deal breakers is up to you.

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 Sealion 8 is a big unit, and its design leans more towards soft and rounded than sharp. There’s a sense of restraint with its pillowy panels, smooth curves and flush door handles all contributing to a clean, almost clinical look.

The 21-inch wheels add a bit of presence, as does the full-width LED light bar with its braided design. But overall, it doesn’t try too hard to stand out. It’s inoffensive - clean and easy on the eye, but it stops short of having any sense of identity.

Inside, the cabin carries that same restrained approach. There’s black leather upholstery, some interesting geometric detailing through the panels and speaker grilles and a generous use of soft-touch materials throughout.

The large displays and panoramic sunroof help lift the space, giving it a premium feel, but more importantly, it’s just a comfortable, easy place to spend time. Which, for a family SUV, arguably matters more than anything else.

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.

Up front, storage and general usability are well thought out. There’s a handy shelf tucked underneath the centre console with two USB-C ports, while a tray above houses the fast wireless charging pad. You also get a sunglasses holder, two cupholders and decent-sized bottle holders in the doors, so it’s easy to keep things organised.

Seat comfort is a highlight, and the overall layout is clean and easy to live with, but the same can’t be said for the multimedia system. While the graphics are sharp and the touchscreen is responsive, functionality isn’t always its strong suit. Wireless Apple CarPlay and Android Auto are included, but CarPlay required reconnecting on every drive during testing and the digital radio and phone calls experienced noticeable signal dropouts. It’s the kind of friction that chips away at the day-to-day experience and starts to feel out of step with how polished the rest of the cabin is.

There’s also a heavy reliance on the screen for core functions. Climate control is integrated, which is fairly standard, but so too are things like headlight controls. It might suit those who are used to navigating everything through a screen, but needing to dig through menus to adjust something like auto high beam on the move feels like a step too far. Bring back buttons.

The second row is where the Sealion 8 really leans into its family-friendly brief. Space is generous, with enough width to comfortably accommodate three adults and the flat floor helps here too. There are three top tether points and two ISOFIX mounts, while charging is covered by a USB-A and USB-C port.

Amenities are a standout. The outboard seats mirror the front with heating, ventilation and massage functions, which quickly become a favourite, alongside dedicated climate controls, roof-mounted air vents and multiple cupholders. A set of sunshades would round things out nicely, but it’s otherwise a very accommodating space.

Access to the third row is less impressive. The manual slide and tilt mechanism feels a little heavy and fiddly to operate and the space itself is best reserved for kids. In practice, that means younger passengers will likely take the path of least resistance, as mine did and simply climb over the second row instead.

Amenities are fairly basic, with directional air vents and cupholders, but there’s no charging provision back there. You do, however, get two top tether points and ISOFIX mounts, which will be a plus for larger families.

Around the back, the boot is a practical, usable space with a wide opening and flat loading floor. With all three rows in place, there’s 270L on offer, which is enough for a few school bags or a grocery run, expanding to 960L with the third row folded. There’s no spare tyre, just a repair kit, which may be a consideration for regional drivers. A 12-volt socket and powered tailgate round things out in this grade.

The BYD Sealion 8 range is relatively straightforward, with two grades on offer and the base variant available with a choice of two drivetrains. For this review, we’re in the flagship Premium AWD, which is priced from $70,990 before on-road costs.

It lines up against the Chery Tiggo 9 Super Hybrid at $65,430 driveaway, the Kia Sorento GT-Line PHEV from $71,130 before on-roads, and the Mazda CX-80 P50e Azami, which stretches up to $87,950 before on-road costs.

On paper, the Sealion 8 Premium doesn’t quite undercut the Chery on price or match its claimed 170km (NEDC) electric-only range, but it’s not far off, with a still-impressive 152km (NEDC). And when you look at the broader package, it starts to make a fairly strong value argument, particularly against its other key rivals.

The 'Premium' badge isn’t just for show, either. Equipment is generous, with highlights including a fixed panoramic sunroof with an electric sunshade, leather-appointed upholstery, a heated steering wheel, and heated, ventilated and massaging seats not just in the front, but for the outboard seats in the second row as well - a feature that hasn’t gone unnoticed by my nine-year old.

Technology is a clear focus. There’s a 10.25-inch digital instrument cluster, a large 15.6-inch touchscreen multimedia system and a 26-inch augmented reality head-up display, alongside wireless Apple CarPlay and Android Auto, a 50W wireless charging pad and a 21-speaker DiSound audio system. BYD also includes 2GB of data per month for the first two years to support its 4G connectivity and over-the-air updates.

Practical touches round things out, with keyless entry and start, NFC card access and a digital key via the BYD app, a powered tailgate, vehicle-to-load (V2L) capability, rain-sensing wipers, sound insulation for the front doors and windscreen and three-zone climate control.

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.

The BYD Sealion 8 Premium is all-wheel drive and pairs a 1.5-litre, four-cylinder, turbo-petrol engine with two electric motors, one on each axle. Combined outputs sit at a hefty 359kW and 675Nm, which comfortably out-muscles its key rivals.

Those figures do drop back to a more modest 110kW and 220Nm when running on the petrol engine alone.

Performance is strong for a large family SUV, with a claimed 0-100km/h sprint time of 4.9 seconds. You can toggle between pure EV and hybrid modes depending on the drive, which adds a layer of flexibility that suits short daily trips and longer highway runs.

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.

Charging is handled via a Type 2 CCS port, with support for up to 11kW on AC and up to 74kW on a DC fast charger. BYD claims a 30 to 80 per cent recharge can be done in as little as 20 minutes under ideal conditions.

The 35.6kWh lithium iron phosphate (LFP) battery is a standout, delivering a claimed electric-only driving range of 152km on the NEDC cycle. That figure is on the optimistic side compared to WLTP testing, but even with that in mind, it remains an impressive number for a plug-in hybrid of this size.

With a full battery, the combined fuel consumption is rated at just 1.0L/100km, translating to a theoretical driving range of over 1000km. Real-world results will vary depending on how often you’re able to charge and the type of driving you’re doing, but after a week that included a fair stretch of highway driving, my trip computer was showing 6.3L/100km. Overall, it’s a solid result, particularly for something with this level of performance.

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.

On-road performance is where things become a bit of a mixed bag. There’s no denying the Sealion 8 Premium is quick and it leans more heavily into its EV character than many large plug-in hybrids. It’s quiet in hybrid mode and responsive off the mark, which makes it easy to keep pace in traffic and overtake when needed. For something of its size, it also does a good job of masking its weight on the move.

Regenerative braking is offered in two levels, but even the stronger setting feels fairly mild. The upside is smoother low-speed driving, with none of the abruptness you sometimes get in hybrids, and it does still recover a decent amount of energy, particularly on longer descents.

Where it falls short is in its overall dynamics. The steering and suspension are tuned for comfort, which results in a soft, slightly floaty feel on the road. It’s not unpleasant and around town it actually suits the car’s brief, but there’s a noticeable lack of feedback and control if you’re expecting something more composed.

Visibility and driver positioning also take some getting used to. The forward view is decent, but the pillars are quite thick and it can be difficult to find a driving position that doesn’t feel a little enclosed.

Judging the edges of the car isn’t always intuitive, and while the 360-degree camera is clear, its perspective can feel slightly off. Objects tend to appear much farther away than they are, which isn’t the most reassuring combination when you’re trying to manoeuvre in tighter spaces.

The BYD Sealion 8 is yet to be tested by ANCAP and therefore remains unrated at this stage. That said, it comes equipped with a comprehensive suite of safety features, along with nine airbags including side chest airbags for the front and second rows.

Standard equipment includes seatbelt reminders for all seating positions, front and rear parking sensors, driver attention monitoring and alert, tyre pressure monitoring, traffic sign recognition and autonomous emergency braking. It also features front and rear collision warning, blind-spot monitoring, rear and front cross-traffic alert and side exit assist.

On the road, however, some of the active safety systems are less polished in execution. The adaptive cruise control can feel abrupt when slowing down and slow to regain speed, while the steering assist can be overly reactive through corners. Lane keeping also lacks consistency, with the system not always engaging as expected.

For families, child seat provision is strong, with four ISOFIX anchor points and five top tether mounts across the cabin, along with child presence detection.

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.

BYD offers the Sealion 8 with a six-year/150,000km warranty and an eight-year or up to 160,000km battery warranty. Both terms are competitive for its class.

Service is recommended every 12 months/20,000km with each workshop visit averaging a solid $596 for the first five years (year four is $1360). Accessing a BYD service centre is fairly easy as there are around 70 centres nationwide now.

BYD recommends premium unleaded petrol (95RON) to be used for the Sealion 8.