Mercedes-Benz S600 vs BMW X6

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.

I was not expecting to like the BMW X6 xDrive 40i M Sport as much as I do. The styling is still polarising but the facelift will throw more people towards the liking rather than disliking side of the fence. The cabin and boot are super practical and the X6 nails all the premium elements you expect at this level. It’s driving and handling are what win me over, though.

My son loves this one and doesn’t want to hand it back. My husband also noted how nice he thought the X6 was… and that’s saying something for a born and raised 'country boy'!

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.

SUV coupe styling with its raised platform and pinched bum just doesn’t do it for me usually but I like it on the new X6 model. The facelift helps the X6 appear more athletic and just plain meaner than the previous version.

The front end sees the most change with new adaptive LED headlights and a bigger 'kidney' grille. The kidneys are illuminated, which adds to its night-time presence and the extended blacked-out intake vents at the front and around the car make it look sharp as hell.

The weird prong on the side mirrors has been dropped in favour of a more seamless design (hurrah) and the 22-inch alloy wheels give total va-va-vroom sport-vibes. 

On the interior, the dashboard has been revamped with a more pronounced shape and a curved display panel that houses the 12.3-inch digital instrument cluster and 14.8-inch multimedia system.

The air-vents now blend more into the dash but the little knobs for them might not be everyone’s cup of tea.

The ambient lighting is customisable and the quilted seats look beautiful but purists will wince on learning it’s synthetic leather, especially at this price point, but it feels and looks very nice. 

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.

You know you’re in a large SUV when you slide into the X6 because the cabin has a lot of space in both rows.

But also because of the higher centre console design, you feel tucked into the car despite the higher seating position. It makes it feel far sportier than your typical SUV. 

Even back rowers enjoy decent legroom and headroom, despite the panoramic sunroof and sloping roof design. Six-footers should be relatively comfortable in both rows but it's best to reserve the middle seat as a sometimes position for adults. The raised floor won’t allow true comfort for a longer trip.

Let’s chat luxury because there’s plenty to be had with the electric front seats and their cloud-like comfort.

The electrically-adjustable side bolsters and adjustable lumbar support makes it feel like you’re being cuddled by the seat and also hold you in place in a turn. The extendable under-thigh supports minimise leg fatigue on a longer trip.

However, the back seat is almost as comfortable as the fronts in terms of cushioning. You also sit in, rather than on top of the seats which is a nice change for an SUV. 

Individual storage is great in both rows and up front you get a dual-opening middle console, glove box and a handy utility area that houses the cupholders and two phone pockets.

There is also a storage nook on the driver’s side that will comfortably hold a wallet. 

In the rear you enjoy two map pockets on the front seat backs and retractable cupholders in the fold-down armrest.

The armrest houses a shallow device holder and sits at a good height. Both rows enjoy deep storage bins in each door and a large drink bottle holder.

Happily, the holder is tilted towards the user, rather than away which is what you usually see.

The boot is a great size at 580L with all seats in use. There’s a little lip that has practical metal scuff plates but otherwise the loading space is level.

The hands-free powered tailgate is welcome and the handy 40/20/40 split on the back row opens up your storage options.

You get a temporary spare tyre underneath the floor and it’s cool how the floor has a gas strut, which makes the area much easier to access.

The concertina-style cargo cover is a bit dicky to use but I like how solid it is. It could easily double as a shelf by itself. 

Charging options are abundant with a total of two 12-volt ports, a USB-A port, three USB-C ports and a wireless charging pad to choose from throughout the car. But it is annoying to use the pad when the front cupholders are in use.

I like having hardened kickplates on the backs of the front seats because my seven-year old loves putting his feet on everything.

The higher ground clearance makes this an easy car to get in and out of but it also makes for a great view for my son. He finds the doors a little heavy to close but the massive door grab handles help!

Amenities in the rear row make it a pleasant space to be in for kids and adults alike. You have reading lights, map pockets, two storage shelves and directional air vents.

There is manual climate control in this row, too, but it feels at odds with the rest of the high tech in the car.

On that note, the updated technology looks gorgeous.

The head-up display is clear and the digital instrument panel offers plenty of customisation. It's a super handy feature to access your recent call log via the steering wheel controls and see it pop up on the instrument cluster. 

The touchscreen multimedia system is responsive but you can also use the rotary dial to get around it. There is a stack of information in it, though, which will take a bit to get your head around. Can’t fault its graphics, it looks hot, but some users may feel flustered at first.

The system has built-in satellite navigation that features an augmented reality feature, which overlays dynamic instructions on the video feed. What makes it practical is how it can be viewed on your instrument cluster, which means more on-road focus for the driver. 

There is wired Android Auto and wireless Apple CarPlay, with the latter being simple to connect to. You don’t have the important climate control buttons/dials up front and I find it annoying to access the multimedia screen to change climate and fan speed settings. 

What you lack in controls there is more than made up for in the centre console. There are a lot of buttons, from the push-button starter, rotary control wheel and everything in between.

Even after a week, my mind still has a mini freeze looking at them while on the go.

There are three variants for the X6 before you jump up to the performance M grade. Our test vehicle is the mid-spec xDrive40i M Sport model and will cost you $144,900 before on road costs.

That places it in the middle of its rivals and you get a well-specified model for the price tag but our test vehicle has also been fitted with a few extras, like the 'M Sport Package Pro' which adds a darkened grille and accents throughout the car, an M Sport exhaust system, red M Sport brake calipers and the M Sport signature colour stitching in the seat belts. All of that adds $2308.

Our test model also has the 'Enhancement Package' which tacks on $4616 but you get some great items like the crystal glass accents on the rotary dial and push-start button and a premium Harman Kardon surround sound system.

It also adds big 22-inch alloy wheels, a tyre pressure monitoring system and a temporary spare tyre which replaces the standard run-flat tyres on the base model.

Oh, and the 'M Brooklyn Grey Metallic' paintwork adds $1539. Just sayin’ it will cost you a pretty penny but it’s not outrageous for a luxury SUV.

Other standard equipment includes synthetic leather trims, electric front seats with heat function, electrically adjustable steering wheel, sports paddle shifters, M Sport styled scuff plates and badging, exterior puddle lamps and a full suite of LED lights including adaptive headlights. 

You also enjoy a panoramic sunroof, adjustable lumbar support on both front seats, as well as extendable under-thigh support.

The drivers seat features two memory positions and comfort entry/exit functions (the seat and steering wheel slide back for you to get in and out of car).

For practicality, there is a hands-free powered tailgate, pre-entry climate control with programable entry time and a boot floor that features a gas strut for easy access.

We’ll touch on the tech later but the highlight is a new curved display panel that houses the 12.3-inch digital instrument screen and 14.8-inch touchscreen multimedia system. 

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 xDrive40i M Sport has a 3.0-litre, inline six-cylinder turbo-petrol engine with maximum outputs of 280kW and 540Nm. That’s 30kW and 90Nm up from the previous model.

It has a smooth eight-speed auto transmission and is all-wheel-drive.

The facelift sees the addition of a new mild-hybrid system which makes for almost imperceptible stop/start functionality when idling and a smidge better on-road fuel economy. 

With a 0-100kmh sprint time of 5.4-seconds, it’s obvious that it has plenty of power to have fun with.

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.

Expectations for a thirsty engine were high, considering the hefty power available, but this version of the X6 has proved to be quite economical.

The xDrive40i M Sport variant has an official combined cycle fuel economy figure of 9.3L/100km but my real-world usage averaged 8.8L/100km.

That’s after mostly open-road driving with only a little ‘city’ thrown in but I didn't hesitate to use the power, so I'm happy with the result.

The X6 has a big 83-litre fuel tank and based on my usage, you’d see a driving range of around 943km, which is great.

BMW only recommends a minimum 95 RON petrol to be used.

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 X6 is a thoroughbred on the road. It’s wide stance and massive wheels provide a well-balanced and grippy on-road ride experience.

Seriously, the tyres feel glued to the road even in the wet. Confidence is high with this one.

There is plenty of power to enjoy and you don’t feel like you’re digging deep for it, either, when you have to get up to speed or overtake.

It has the handling and power of a much smaller and sportier car but at no point does it feel wild or reckless to drive. It’s got a certain elegance and maturity to its handling.

Despite those massive wheels, the ride comfort is fantastic with the adaptive suspension. You still feel the road but you’re not knocked about by it. It’s very much a driver’s car in that sense but passengers still feel well-cushioned.  

The cabin is insulated and you get basically no road noise or wind noise but occasionally you get some feedback from the tyres depending on the road surface. Longer journeys are comfortable and quiet.

The steering is light enough that you don’t feel like you’re hauling a massive SUV around but is still responsive. Meaning you can tackle a winding road or urban traffic easily.

When it comes time to park it, you’ll love having the 360-degree view camera system. It’s the best and clearest system I’ve sampled.

Add the front and rear parking sensors and no car space is an issue. But if you’re unsure, you can use the Park Assist feature to help out.    

The X6 has an extensive safety list and I like the SOS emergency call button and front cross-traffic alert. Both are great to have but the latter is particularly useful on a large SUV like this, especially in the city or driveways.

Other standard safety equipment includes blind-spot monitoring, autonomous emergency braking, LED daytime running lights, forward collision warning, side collision warning, rear cross-traffic alert, lane keeping aids, lane departure warning, intelligent seat belt reminders, front and rear parking sensors, 360-degree view reversing camera, traffic sign recognition, driver fatigue monitor, and adaptive cruise control with stop and go functionality. As well as an SOS emergency call button and stolen vehicle tracking.

The X6 hasn’t been tested by ANCAP, so it’s unrated but it is based on the X5, which achieved a five-star rating in 2018. However, it only features six airbags which is low for a family car.

There are ISOFIX child seat mounts on the outboard seats and three top tethers in this row. Two seats will fit best but I reckon you could squeeze a third in if you had to.

There’s plenty of room for front passengers when you install a 0-4 rearward facing child seat, too, which is good.

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 ongoing costs are surprisingly reasonable for a large luxury SUV! Like its rivals the X6 enjoys a five-year/unlimited km warranty.

However, you can pre-purchase a servicing plan for up to five years or 80,000km, whichever occurs first, for a flat $2400. Or an average of $480 per service which is inexpensive for this class.

Service intervals are also good at every 12 months or 15,000km, whichever occurs first.