Mercedes-Benz Gls450 vs Citroen C5 Aircross

What's the difference?

The new GLS is everything you’d expect of a Mercedes-Benz with an S in its name. Luxury, performance, space, and in this case, thoughtful practicality. A super-capable, super-sized family truckster with the lot.

So, what did my family think about the Citroen C5 Aircross Sport?

I love how it looks and its updated safety list. It’s fairly spacious inside and has a great boot space but it’s lacking a lot of family-orientated practicality in the back seat. The lack of individual storage and amenities is noticeable when you have a kid or two but even as an adult, not having a cupholder for your coffee/drink on a trip feels odd.

The multimedia system and reversing camera need to be improved, too. Overall, it will suit a small family which is out of the baby stage but can’t yet justify upgrading to a larger SUV. It gets a 6.5/10 from my family. 

Launched globally in mid-2019, Merc describes the GLS as the S-Class of SUVs, which is apt given its 5.2m length, 2.5-tonne mass, and ultra-premium specification.

As mentioned, the GLS is big; a step up from the already substantial model it replaces. Built with the US market in mind, in fact it’s produced in Tuscaloosa, Alabama, it’s more than five metres long, close to two metres wide, and over 1.8m tall. And there’s more than three metres between the axles, a 60mm wheelbase increase over the previous model.

And despite the size of the canvas, the Benz design team has managed to make the GLS look like a modern Merc. Signature elements include obvious ones like the slatted grille with a couple of three-pointed stars on the nose.

But there’s also, the carefully chiselled twin ‘power dome’ bonnet, scowling LED headlights and vents to aid front brake cooling and smooth aero performance around the front of the car.

The big beast’s off-road intent is highlighted by extensions around the wheelarches, with big optional 22-inch rims sitting underneath. The fact they look right-sized for the car speaks volumes about its scale.

The racy AMG Line package is standard, and a recess and pronounced character line, tightening the lower waistline is a familiar Merc treatment, plus alloy roof rails toughen the look while dialling up practicality.

The rear is relatively simple, borderline generic, with tapered tail-lights offering the only strong whiff of design personality. But believe it or not, thanks to careful detail sculpting of the body, and smoothing underneath the car it boasts a drag figure of Cd 0.32. Outstanding aero performance for a large SUV.

The driver and front passenger are presented with a sweeping dashboard dominated by twin 12.3-inch digital screens, one primarily covering the instruments, and the central screen managing the MBUX media system, including audio, nav, phone integration, car set-up, and more, plus ‘Hey Mercedes’ voice control.

The overall feel is simple, and restrained, yet massively confident, with a subtle colour palette, large squared-off elements defined by brushed metal finishes, and an obvious, intense attention to detail, from the haptic controls to the beautifully finished, multi-function steering wheel.

And the standard Burmester audio system includes a two-way in-car communication function that subtly amplifies the driver and front passenger’s voices for those in the third row, and vice versa. Sheer genius.

The facelifted model sees a sportier front with the grille redesigned to highlight the double chevron badge.

The bonnet curves around the badge, as do the two long LED strip lights that connect the headlights. The bonnet also sports new divots that give it a gruffer edge.

The wide profile at the rear and new three-pronged tail-lights create some interest.

The black plastic moulding that runs along the base of the car could look unfashionable on a lighter colour but on our blue paintwork, it looks good. As does the contrasting black roof!

The interior trims are finished in a combination of synthetic and Nappa leather but boast a two-tone colour which might not land with everyone. Particularly given the navy portions seem to be glittery in certain lights.

Sitting at 1859mm wide, 1695mm high and just 4500mm long, the overall exterior design is sporty but cute. It should appeal to those who want a nice-but-not-loud-looking car and something that is easy to park.

Space is obviously a critical factor here, and no surprise there’s copious amounts of it inside the GLS.

Front seat passengers enjoy plenty of breathing room, without feeling remote from one another, and there’s lots of storage in the shape of a large lidded box/armrest between the seats, a decent glove box, two big cupholders and jumbo door pockets with room for large bottles.

There’s one data-enabled USB port in the front, two charge-ports in the second row, and four in the third row. Shouldn’t be any complaints about powering mobiles, tablets or games.

The second row feels every millimetre the SUV limo. Simply getting in and out is made easier because an auto lowering function drops the car 25mm when one of the doors is opened.

I was able to sit behind the driver’s seat set for my 183cm position with heaps of head and legroom on offer. And there’s an extra 10cm of electrically adjustable travel to play with if those in the third row agree.

The fold-down centre armrest features a lidded storage tray and twin pop-out cupholders. There are netted pockets on the front seatbacks, and again, the door bins are big enough for large drink bottles.

Three adults across the rear is a breeze, there’s climate control ventilation, and a huge glass sunroof is standard. Rather than asking ‘Are we there yet?’ the kids will be disappointed when you arrive!

Then there’s what the Cleary family refers to as ‘the way back seat.’ A pair of third row seats for the lucky kids that get to inhabit their own little world. Getting in and out is relatively civilised thanks to electric slide and tilt for the second row seats, and space is generous. I could sit comfortably, so the kids will be all smiles.

With all seats upright cargo capacity is enough for a seven-person day trip (355L VDA). Press the button to fold the 50/50 split-fold third row down and your options expand substantially (890L). And with 40/20/40 split-folding second row lowered, transportation of a full, three-ring circus is on the cards (2400L). Overall, more space than the arch enemy BMW X7.

Plus, the ability to lower the car 50mm thanks to the standard air suspension makes life even easier. And one button lowers the second and third rows at the same time.

The spare is a collapsible space-saver, and towing capacity for a braked trailer is 3500kg, with a tow ball weight of up to 140kg. The ESP system also features a trailer stabilisation function that counters oscillation with “braking intervention.”

The interior is spacious for a medium SUV but the back seat knocks off some points for family practicality. So, let’s start in the back.

Despite there being plenty of headspace for my 168cm (5’6’’) height, the legroom is cosy behind my driving position.

Meaning a 0-4 rearward facing child seat will encroach on front passenger space. It’s probably best suited to a family which is out of the baby stages but it was cumbersome fitting my big harnessed-booster seat in there, too.

It has ISOFIX child seat mounts on the outboard rear seats and three top tethers but two seats will fit best. The floor is flat, which offers far more comfort for a middle seat passenger and I love how the seats can be individually shifted.

The amenities and storage in this row are sparse. You get directional air vents, reading lights, netted map pockets and shallow storage bins in the doors.

Siblings may squabble over the single USB-A port on a long road trip but more than that, there are no cupholders or drink bottle holders back there or even a centre armrest.

That said, the 182mm ground clearance made it an easy car for my six-year-old to get in and out of; plus, the stadium-like seating and wide windows meant he had an awesome view this week.

Now for the front. It has ample amenities, storage and tech. You get plenty of head- and legroom, plus with the panoramic sunroof the cabin manages to feel airy, too.

Individual storage is great with an extra deep middle console, glove box, two cupholders, bins in each door and two very handy utility trays situated near the toggle-type shifter.

Charging options are much better up front, too, and you can choose between a wireless charging pad, two USB-A ports and a 12-volt socket to charge your device.

It's super easy to connect to the wired Apple CarPlay and there’s wired Android Auto for those users.

The built-in satellite navigation is straightforward but that’s where the simplicity ends. I did not find the multimedia system or the digital instrument panel to be terribly intuitive to use and the touchscreen controls can be laggy.

I’m sure you could get used to it over time but I felt flustered.

For this size SUV, the boot space is great at 580L with all seats in use but you can bump it up to 1630L if you fold the back row.

The floor can be adjusted to make a level load space or dropped to give you greater depth for bulkier items and there is a temporary spare tyre underneath the floor.

There are luggage tie-down anchors, a cargo blind and I always like having a powered tailgate. 

There is only one model for the C5 Aircross Sport and it will set you back $54,990, before on-road costs.

That prices it as the most expensive compared to its rivals with the Mazda CX-5 GT SP ($51,810) coming in closest but the Nissan X-Trail ST-L ($46,790) and the Kia Sportage SX+ ($41,850) are even more affordable.

The only included paint colours are 'Polar White' and 'Nera Black'. Our model’s 'Eclipse Blue' will add on $690.

However, the C5’s price tag doesn’t feel too cheeky because of the feature-heavy specification, including heated front seats, electric driver’s seat with massage function, a panoramic sunroof and a mix of premium Nappa leather and synthetic leather interior trim.

You also get a powered tailgate, rear privacy glass tinting, full LED lights on the exterior, individually sliding seats on the back row and black 19-inch alloy wheels.

The technology has been upgraded with the dashboard being headlined by a 10-inch touchscreen multimedia system and a 12.3-inch digital instrument panel.

Built-in satellite navigation, as well as wired Apple CarPlay and Android Auto are also included as standard equipment.

On top of that, the safety list has been significantly improved, but more on that later. 

There are two engines on offer. The 3.0-litre (M256) in-line six-cylinder turbo-petrol GLS 450 4Matic, and the 2.9-litre (OM656) in-line six-cylinder turbo-diesel GLS 400 d 4Matic.

The all-alloy, twin-scroll single-turbo petrol engine delivers peak power of 270kW from 5500-6100rpm, and maximum torque of 500Nm across a broad plateau from 1600-4500rpm. It also features a 48-volt electrical system driving the ‘EQ Boost’ set-up, able to deliver an extra 16kW/250Nm for short periods. The integrated starter-generator also enables energy recuperation.

Although the all-alloy, twin-turbo diesel features variable valve lift it gives some ground on power, offering up 243kW between 3600-4000rpm, but torque is a solid whack, with 700Nm on tap from 1200-3000rpm. Worth noting, that to minimise emissions this engine features a “selective catalytic reduction converter” in the exhaust, which brings with it the use of an ‘AdBlue’ reducing agent. The separate AdBlue tank has a capacity of 31.6 litres.

The nine-speed auto transmission is the same in both versions, although the diesel has a slightly lower final drive ratio.

The C5 Aircross Sport has a 1.6-litre, four-cylinder turbo-petrol engine with a maximum power output of 133kW and 250Nm of torque. It’s not super grunty but there’s plenty here to keep you up to speed on the open road.

It is a front-wheel drive and has an eight-speed auto transmission but the gear changes can feel a bit jerky at lower speeds.

Claimed fuel economy for the combined (ADR 81/02 - urban, extra-urban) cycle for the GLS 450 is 9.2L/100km, the more frugal GLS 400 d trimming that to 7.7L/100km. The petrol 450 emits 210g/km of CO2 in the process, the diesel 400d dropping that slightly to 202g/km.

Stop-start is standard, you’re looking at premium unleaded for the 450 GLS, and you’ll need 90 litres of dinosaur juice to full the tank on both models.

Ah, this is where it earns back some points!

I was very impressed by the efficiency of this because the official combined cycle fuel figure is 5.7L/100km and my real-world usage came to 6.2L! That’s fantastic for this sized SUV and for a turbo.

With a fuel tank of 53L and based on the combined fuel figure, you should be able to get a driving range of around 930km, which is good for those families who like to do road trips.

Merc claims the GLS 450 will sprint from 0-100km/h in 6.2sec, and the 400 d in 6.3sec. Not hanging around for a 2.5 tonne mothership. But the standout is the 400 d’s torque. All 700Nm of it available from just 1200rpm to 3000rpm; right in the mid-range sweet spot.

The nine-speed auto transmission is smooth yet responsive, with paddles on the wheel for manual shifts when you want to pick the ratio. The combination of effortless grunt and the nine-speeder keeping things on the boil is an impressive one.

Suspension is by double wishbones at the front and multi-links at the rear, and while you can feel the weight in cornering, the standard Airmatic air suspension (which does away with steel springs) is superb in terms of ride comfort and body control.

We took a deep breath and pushed enthusiastically through a series of sweeping corners and the fat (285/45 fr - 325/40 rr) Continental ‘PremiumContact 6’ rubber wrapped around our car’s (optional) 22-inch rims gripped hard.

The ‘4Matic’ all-wheel drive system also seamlessly shuffles torque between the front and rear axles (theoretically up to 100 per cent in each direction).

Merc has put extra focus on body rigidity, the tuning of engine and suspension mounts, and sound absorption, and it shows. The GLS 400 d is beautifully refined on the highway. A neat touch is the car automatically lowering 15mm at motorway speeds or when ‘Sport’ mode is selected.

Steering is electromechanically assisted, and Merc says the front suspension geometry has been revised to minimise vibration through the wheel. And yes, feedback is minimal, but unfortunately so is road feel with only a general connection between your hands on the wheel and the front tyres on the bitumen.

When you’re steering a large beast like this, often with something substantial hitched to the back, you want to know braking performance is up to the task, and the GLS’s big ventilated discs all around deliver reassuringly strong stopping power, with nice, progressive pedal feel to boot.

The seats are adjustable six ways to Sunday, but beyond that they’re comfortable and supportive, even over long stints behind the wheel.

We stayed on the bitumen, because, let’s face it, that’s where this car will spend 99.9 per cent of its time, with the exceptions of the boat ramp, a ski weekend or pony club.

For those special occasions the optional ‘Off-road engineering package’ adds a low-range transfer case, inter-axle locking, hill descent control, and under body armour for more serious work.

Despite its city-friendly size, the C5 Aircross Sport is just as happy cruising on the open-road as it is in an urban environment.

The ride is smooth enough once you get up to a steady speed but the suspension can feel harsh on a bumpy road.

Also, the auto stop-start function can make it feel sluggish to respond, so I disabled this on most trips.

There is plenty of power so you'll feel confident overtaking or getting up to speed on the open road. However, you have to be a little more aggressive with the accelerator when you’re hitting hills.

The steering can, at times, feel vague when you’re at lower speeds but is otherwise responsive.

The cabin space is quiet and nice to be in on the highway and you’ll be able to chat with your passengers with ease.

What I like most about this though is the visibility – the windows are large and I feel like I have a clear view most of the time, which isn’t always the case in an SUV.

Parking this is a cinch with entry to tight car parks helped by a 10.7m turning circle!

However, the 180-degree view camera isn’t great and near hopeless at night time. A clearer image would be welcome but front and rear parking sensors ease the annoyance.

The updated safety list is most welcomed, especially on a family SUV.

The C5 Aircross Sport has the following as standard - daytime running lights, forward collision alert, lane keeping aid, lane departure alert, blind-spot monitoring, rear cross-traffic alert, intelligent seat belt reminders, traffic sign recognition, 180-degree view reversing camera, front and rear parking sensors and adaptive cruise control with stop and go function.

Special mention for the new fatigue detection alert. When it triggers it doesn’t stop sounding until both of the driver's hands are detected on the steering wheel.

The autonomous emergency braking with car, pedestrian and cyclist detection is operational from 10 – 80km/h (5.0 -140km/h for car detection), however the pedestrian and cyclist functions are only detectable in the day time. It’s usual to see it operational at night, as well.

Despite the new safety items, it still only has six airbags, which includes curtain airbags covering both rows but that’s pretty low for a family car nowadays.  

It was awarded four from a maximum five-star ANCAP safety rating back in 2019 but didn’t have all of the new items at the time of testing.  

The Mercedes-Benz range is covered by a three year/unlimited km warranty, which, like Audi and BMW continues to lag behind the mainstream market where the majority of players are now at five years/unlimited km, with some at seven years.

On the upside, Mercedes-Benz ‘Road Care’ roadside assistance is included in the deal for three years.

Service is scheduled for 12 months/25,000km (whichever comes first) with pricing available on an 'Up-front' or 'Pay-as-you-go' basis.

As a guide, service pricing for the outgoing GLS is set at $2600 per service (up-front) and $3250 (PAYG), a saving of $650 a pop. Fourth and fifth services are also available for pre-purchase ($3550 and $4900).

The on-going costs are super-reasonable on the C5 Aircross Sport, with a five-year/unlimited km warranty included.

You can also choose to pre-purchase a three- or five-year capped-priced servicing plan, both significantly cheaper than the pay-as-you-go option. 

On the three-year plan, services are $1100 or an annual average of $366.

It’s a flat $2000 for the five-year plan, (averaging just $400 per service), which is very competitive for the class.

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

The Aircross also comes with a five-year roadside assistance plan that is offered through Digicall Assist, for added peace-of-mind.