BMW X4 vs Mercedes-Benz GLS-Class

What's the difference?

Okay, so the BMW X4 xDrive30i is neither an ass nor an elbow, to be fair, it's more of a bulky shoulder muscle, or two.

I can't say I'll ever love the X4, the idea of it is a bit too weird for me, but I can't help admiring the way it looks and the way it drives.

It's a bit like a sedan on steroids - or an SUV on a diet, depending on your perspective - but that doesn’t take away from the fact that it’s fun to drive, comfortable and retains just enough coolness, and just enough practicality, to make it worthwhile.

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.

So here's the thing. Obviously I have a personal beef with the existence of vehicles like this, but my eyes cannot deny the facts - the X4 looks fantastic. It's muscular, imposing and smooth all at once. Unlike the X6, a bigger and less visually successful attempt to play the same styling tricks with an X5, it doesn't have a ridiculous rear view that looks like it shoulders and buttocks have been fused (although it's hard to miss just how small the rear window is).

Even more impressively, there's no denying it looks better than the X3 that gave birth to it, so I can easily see why someone in a BMW showroom could be drawn to it. At least until they sit inside.

If the exterior style and eye-catching Sophisto Grey metallic paint don’t make an immediate impression then your eyes will surely widen at the interior, resplendent with bold Tacora Red seats, Aluminium Rhombicle trim finisher and the kind of sleek, classy styling that BMW excels in. 

Both the adjustable ambient lighting on the doors (we were partial to lilac) and door projectors that shot out what looked like robot wings onto the ground every time we hopped out of the X4 at night walked a fine line between futuristic cool and “parked out the front of a nightclub entrance” chintz, but over time the scales tipped more to the former. 

The big differentiator between the X4 and X3, of course, is the sloped coupé roof, a design feature that may make the X4 look a little cooler, but at the expense of cabin space, but more of that in a moment.

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.

For a car that is very much a mid-sized SUV on the outside, the interior can feel a bit too snug, like you’re driving a compact car that’s tried on a suit a few sizes too big (for reference, I’m 175cm tall - above-average height drivers may find the snugness soon turns to claustrophobia). 

While comfortable - it is BMW we’re talking about, after all - there’s not an overly abundant amount of headroom available, a feeling that becomes more pronounced should you shut the big moon roof.

My two children felt slightly too close to “you’re annoying me” distance from one another, which is to say this isn’t really the kind of car you should be getting if you plan on regularly ferrying about passengers in the rear who are bigger than a child. But I really don't think many people with kids would choose the X4 over the X3.

Boot space also takes a hit when compared to the X3 (550 litres versus 525-litres in the X4 - I was surprised the difference wasn't larger - although that expands to 1430-litres with the rear seats folded down. 

The boot opening is also mouth-shaped, which makes packing in wide-load items more of an issue.

Cupholders are plentiful - two in the front, two in the rear, and bottle holders in each door - and there’s a decent-sized storage cubby in between the front two seats. 

The sloped roof, and big fat A pillars, also result in the X4 being a bit more pinched at the rear, which is not especially great for visibility, with the vehicle’s blind spots taking some getting used to.

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.

Our Polar White test vehicle, which is the base grade in the three-tiered GLS range, comes standard with a 3.0-litre inline six-cylinder turbocharged diesel engine with 48V mild hybrid technology, nine-speed automatic transmission, permanent all-wheel drive and active air suspension for a list price of $189,100.

This pricing is higher than comparative entry-level grades offered by the two marques which dominate sales leadership in this segment, comprising the BMW X7 xDrive40d M Sport ($179,500) and Lexus LX500d AWD ($158,700).

The GLS450d’s standard features include 22-inch AMG alloy wheels with Continental 325/40 R22 tyres and a collapsible spare, ‘AMG Line’ body styling enhancements, aluminium-look illuminated side-steps with non-slip rubber studs, multi-beam LED headlights and more.

Step inside the keyless interior and you’ll find ‘Hey Mercedes’ voice activation, fingerprint scanner (which memorises individual comfort settings for up to seven users), panoramic sunroof, heat-insulating dark-tinted rear privacy glass and the ‘Premium Plus Package’ that includes heating/cooling for the front seats, heated rear seats, head-up display, separate front/rear climate control zones, heated cupholders and more.

There’s also a concert hall-like Burmester surround sound system controlled by a central touchscreen with digital radio and Apple CarPlay and Android Auto connectivity, plus wireless phone charging, multifunction Nappa leather sports steering wheel and USB ports front and rear.

Driver assistance includes the ‘Parking Package’ (360-degree camera, active parking assist and transparent bonnet), ‘Mirror Package’ (auto-dipping rear-view mirror and electric folding door mirrors with puddle lamp projection of the brand logo) and ‘Driver Assistance Package’ (blind-spot assist, exit warning, speed sign recognition, lane keeping etc) all included as standard equipment.

Of course, Mercedes-Benz offers numerous extra-cost options including a 3500kg towing package plus interior, exterior, suspension and wheel enhancements (including Nappa leather trim) for those who want their GLS with the lot, which can easily push the list price beyond $200K.

Now, prepare to be confused. In the past, the 3.0 in the xDrive3.0i nomenclature might have led you to believe you'd bought a BMW with a 3.0-litre straight six engine. But in this case, you have not, the 3.0 just means you have a more exciting version of the 2.0; a TwinPower turbo 2.0-litre inline four-cylinder engine, making 179kW and 353Nm that the xDrive system delivers to all four wheels. 

The claimed zero to 100km/h time of 4.9 seconds feels completely realistic as this engine has plenty of poke. Put it in the Sport setting and you'll get some serious shove. Indeed, the switch between Comfort and Sport is very noticeable and changes the character of the car entirely.

The transmission is an eight-speed conventional torque converter automatic gearbox that’s both smooth and responsive. 

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.

The X4’s 65-litre tank needs to be 95-octane at a minimum, and BMW’s claimed combined fuel consumption is 7.9 litres per 100km. The temptation to use its rorty little engine is going to push you higher, though - you chose the one with the 3.0 badge on it after all - and we averaged 10.9 litres per 100km in our week together, which was mainly city driving, to be fair. 

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 impressive trick that BMW continually pulls off with its SUVs is giving them the same sensual, muscular steering as its sedans, and an impressively similar ride and handling balance.

The steering is the highlight here, but it's also noticeable how planted to the road it feels.

The X4 speaks to its looks, in fact, by feeling sportier and more alive to drive than you'd expect an X3 to be.  

This is less an SUV for soccer mums and dads, and more a bastard love-child that’s into loud leather and bright neon - a CEO who dressed punk rock-lite on weekends, if you will. 

If those weekends are bereft of child taxiing and loading up the boot with several tons of kid stuff, then you’ll have a blast in the X4. 

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.

The GLS does not have an ANCAP rating as it’s yet to be tested, but comes standard with a suite of passive and active safety features including nine airbags, auto emergency braking (AEB) with pedestrian detection and junction assist, blind-spot monitoring, traffic sign recognition, head-up display, rear cross-traffic alert, lane-keeping, adaptive cruise control with ‘distance assist’ (autonomously brakes/accelerates in heavy traffic), front/rear parking sensors, 360-degree camera and more.

There’s also two ISOFIX and three top-tether child seat anchorages in the second row, plus two more of each in the third.

Despite all the brouhaha about other car manufacturers offering more generous warranty periods - seven years for Kia, for example - BMW has not shifted its stance, still offering its standard three-year unlimited-kilometre warranty. Frankly, it's just not good enough.

BMW also offer a Service Inclusive package for $2010 that covers owners for five years, or 80,000km.

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.