BMW X3 vs Mercedes-Benz C63

What's the difference?

This is a highly competent all-rounder, given that it has the comfort and practicality for urban family duties yet with its revered M breeding can produce a level of performance which, in competent hands, could hold its own at a track day where its capabilities could be safely explored.

The Mercedes-AMG C 63 S Aero Edition is an absolute beast of a car, but it comes at a pretty hefty price. Yes you get a lot of performance, and the fact there are only 63 examples being made for Australia and New Zealand could be enough to get you to sign on the line. For me, though, if I was after a C 63, it’d have to be a wagon. It doesn’t need an Aero pack to look better.

The fourth-gen X3, which has a lighter but stiffer body, shares the same wheelbase as its third-gen predecessor but at 4755mm end-to-end it's 34mm longer and it's 29mm wider.

It’s also 25mm lower, which combined with front and rear track-width increases and adaptive suspension damping to sharpen the handling underlines its sportiness and driver appeal, despite a substantial 2055kg kerb weight.

The new exterior design is characterised by short overhangs, flush door handles, a larger ‘split kidney’ grille, new LED taillights and L-shaped light elements for the LED headlights.

The new interior design is a classy mix of soft-touch materials and high-gloss hard surfaces in tastefully contrasting tones. The seats are upholstered in a new synthetic leather called 'Veganza' ('Espresso Brown' in our example) which according to BMW requires 85 per cent fewer CO2 emissions to produce than genuine leather (which is still available as an extra-cost option).

Combined with subtle use of ‘Magnolia’ fine-wood trim inserts, satin chrome, piano black, blue/red M highlights and slender ambient light-strips, it’s a cabin that exudes opulence.

I’ve never been the biggest fan of the current C-Class Coupe’s styling. To me, it has always looked a little droopy, a little melted at the back. 

I have to say, the Aero Edition has changed my opinion somewhat, as the new graphic elements help lift it up a bit, visually raising its rear up like a stretching cat, tail in the air. I’m still not 100 per cent on it, but to my eye it’s better.

The carbon-fibre trim elements that have been added to the exterior certainly add some menace to the look, too, and I simply can’t help but constantly notice out of the corner of my eye the AMG pressing in the staggered, dished rims. At a glimpse, from a distance,  it looks like rim damage, but thankfully it’s not!

The staggered set-up does really add some width and mongrel to the look, as if it needed more, with its open maw lower bumper air dam, and the signature 'Panamericana' grille treatment which looks like an evil character out of a movie. If you know the one I’m talking about, let me know in the comments.

As much as the look matters when it’s parked in your driveway, it’s the cabin that arguably matters more, right? That’s where you spend your time, after all. Check out the interior images to see if you think it lives up to the exterior look.

This would make a great family weekend escape machine, for which BMW quotes a 645kg payload rating. It’s also rated to tow up to 2500kg of braked trailer, which could pose a challenge given the relatively low 100kg tow-ball download limit (TBD is typically around 10 per cent of trailer weight).

BMW also does not publish a GCM figure (how much it can legally carry and tow at the same time) so we can’t confirm if it can carry its maximum payload while towing its maximum trailer weight.

Even so, the M50 has a useful-sized luggage area which offers up to 570 litres (or 0.57 cubic metres) of load volume with the rear seat upright.

This expands to 1700 litres (or 1.7 cubic metres) with the rear seat folded flat, which can be handy for a multitude of tasks like transporting a mountain bike or hauling home flat-pack furniture.

There’s comfortable space for the driver and front passenger, along with useful storage including large bottle-holders and bins in each front door.

The centre console has two small-bottle/cupholders plus wireless phone-charging and a pair of USB ports. There's also a glove box plus another box at the rear of the console with a padded lid that doubles as an elbow rest.

The rear bench seat is surprisingly spacious, given that I’m 186cm tall and when seated behind the driver’s seat in my position I still have about 40mm of knee clearance, which is optimised by the concave shape of the front seat backrests.

The spacious and airy feel is enhanced by the ‘panorama’ glass roof which spans the full length of the seating area and allows generous headroom even for tall people.  

However, shoulder room is tight for three adults and the centre passenger’s feet must contend with the transmission tunnel, so even though it would be fine for three kids we’d suggest a limit of two adults for longer trips.

Rear passengers get privacy glass and pull-up roller sunshades, large-bottle holders and bins in each door plus net-type pockets and anchorage points for media devices on each front seat backrest. There are also two small-bottle/cupholders in the fold-down centre armrest.

The rear of the centre console has two USB ports, adjustable air-vents plus controls for zone temperature, airflow preferences and seat-heating.

The bench seat features a 40/20/40 split, which allows the centre backrest to fold forward independent of the two outer backrests to allow long loads like snow skis, home hardware etc to be carried if securely fastened.

A power tailgate provides access to the luggage area, which is equipped with a handy 12-volt accessory socket plus load-anchorage points front and rear, extra storage nooks for small items on either side and a retractable roller-type load cover. Overall, this vehicle offers good practicality for family duties.

No two-door coupe is going to offer you the space and comfort of a sedan or wagon, that’s just a fact. But that only matters if you plan to actually use the rear seats. If you don’t, then the Coupe version of the C 63 S might be perfect for you.

Even so, I managed to (only just) squeeze myself between the seat and the door opening to slide into the rear row. This won’t be easily achieved by all attempters, especially on the driver’s side.

Let’s just say I probably looked like I was doing something very weird to the driver’s seat as I spider-manned my way in. 

The rear space is tight for someone my height (182cm/6’0”) behind their own driving position, with knees hard-up against the seat in front and not much headroom (my noggin’ was brushing the ceiling) or toe space (size 12s don’t fit so well) to speak of.

It’s certainly a selfish car. Or maybe it’d be fine for smaller kids. There are two spaces in the back, both with ISOFIX child seat anchors and top-tether points.

But there is storage in the back - cupholders and storage caddies either side of the seats, though the storage situation improves in the front zone, with bottle holders in the doors, cupholders between the seats, loose item storage under the media screen and a covered centre armrest bin, too.

The front cabin is a special looking place, with carbon-fibre abounding across the dash and nice trim on the doors. The AMG steering wheel is a sight to behold - it’s a flat-bottomed unit with carbon-fibre and Dinamica (that’s Benz talk for microsuede) trim: perfect for sapping sweat as you manhandle the C63 through the bends.

The seats are AMG Performance sports units up front, and the trim used is reserved for this model specifically: Nappa leather with yellow stripes. There are yellow details elsewhere, including on the rear seats, centre console and dash, and it certainly adds some visual excitement.

Media is controlled by a 10.25-inch display and Mercedes-Benz’s touchpad control system, but there is no touchscreen - rendering the Apple CarPlay and Android Auto smartphone mirroring technology somewhat tedious.

I’ve always had a gripe with screens that don’t allow touch but feature the tech that’s designed to transfer your phone’s screen to the media unit, and I can tell you the longer you spend twiddling the dial to get where you want to go, the more annoying it becomes.

The Burmester sound system has 13 speakers and is rather good, but I prefer the sound from the standard fit variable sports exhaust. So maybe that quibble with CarPlay isn’t that big a deal.

And if you just want to charge your phone, and there’s a second USB port up front, as well. Note: in non-Aero Edition C 63 models without the carbon-fibre interior pack, you also get Qi wireless phone charging, but it’s deleted from this variant and any model with the carbon pack.

The driver has a 12.3-inch digital info display to show where you are and what the car is up to, and there’s a head-up display as well. Yep, there’s standard sat nav with live traffic updates (and even live fuel price updates) - it’s just a shame the maps still look early 2000s-spec in 2D layout.

Cargo space is okay. The claimed cargo capacity or boot volume is 355 litres (VDA) with the rear seats in place. That’s small for a coupe of this size, and the shape of the boot (with a hump behind the rear seat) isn’t great as things do move around quite a bit.

But, thankfully, Mercedes has included its clever foldable storage box system under the boot floor - it goes where you might usually expect a spare wheel, but there isn’t one in this car. Instead you get Mercedes’ 'Tirefit' repair kit with an electric pump.

Look, I’m not likely to ever be in the position to say that a car that costs $188,600 plus on-road costs is “good value”, but to be honest, if you’re in that position, you’ll be getting plenty of car for your cash.

The Carbon Edition of the C 63 S Coupe adds $17,200 over the standard version of the high-performance two-door, but it adds a bunch of extras to help justify its price. A car like this is always going to be seen by some as a profligate purchase, right? You need to be able to justify spending an extra MG3’s worth of cash on this Edition. 

The noticeable exterior bits include an AMG Performance rear spoiler, a model specific front lip, rear diffuser, and side facings for the rear apron air vents. Carbon-fibre is used in the front apron A-wing, the side sill inserts, rear diffuser insert, rear spoiler and the side mirror casings. 

There’s more carbon-fibre inside the cabin, which we’ll cover off in the interior section. Other additions over the standard C 63 S Coupe include ceramic composite front brakes (402mm six-piston) and 360mm single-piston rear brakes, and there are “ultra-lightweight” AMG forged 'Matt Black' alloy wheels with 19-inch rims at the front and 20s at the rear. 

And in nice news, the car you see here has no optional extras fitted at all. The colour is 'Iridium Silver', one of only two options for this limited run model (the other available hue is Polar White, and both come at no extra cost).

Standard inclusions comprise leather interior trim, heated and electric adjustable front seats, dual-zone climate control, a 10.25-inch media screen with sat nav and smartphone mirroring, DAB radio, 13-speaker Burmester sound system, 12.3-inch digital driver info display, head-up display (HUD), ambient lighting, and performance items like active dynamic engine mounts, an adaptive AMG performance exhaust, a rear differential lock, and adaptive sports suspension.

Plus there’s a full-spec safety offering which we’ll cover in the section below.

Thinking about what cars compete with this one? There’s the Audi RS 5 Coupe (from $150,900), the Lexus RC F (from $136,636), and the BMW M4 Competition (from $167,829). So the C 63 S - which is already expensive comparatively - looks positively pricey in Aero Edition spec.

According to BMW, the M50 xDrive features the most powerful inline six-cylinder petrol engine fitted to an M Performance model.

This 3.0-litre unit clearly benefits from BMW’s twin-scroll turbocharging technology, which combined with variable valve timing and an extra 13kW/200Nm from the 48V mild-hybrid technology produces a stomping 293kW of power at 5500rpm and 580Nm of torque at 1900rpm.

It also has a ‘boost’ function, which provides an extra burst of power for short periods when maximum acceleration is required when overtaking etc.

It’s activated by the left paddle-shifter on the steering wheel and automatically optimises transmission/chassis settings to suit. There’s also a drive mode selector, with ‘Sport’ offering the most responsive and engaging experience.

The eight-speed torque converter automatic is a refined and efficient transmission well suited to this full-time all-wheel drive application. Rapid-fire manual shifting is also available using the steering wheel paddles.

Open the shapely bonnet of the C 63 S and you’ll find a hand-assembled horsepower-monster engine with a printed name plaque to prove it.

The 4.0-litre twin-turbo V8 produces 375kW of power at 6250rpm, and 700Nm of torque from 2000-4500rpm. It runs a standard-fit nine-speed 'Speedshift MCT' (multi-clutch transmission) automatic, and it’s rear-wheel drive. And yes, that means it likes to boogie.

The claimed 0-100km/h time is just 3.9 seconds, and top speed is apparently pegged at 250km/h. Yeesh.

The name on the “Handcrafted by” plaque on this particular engine? Hat tip to you, Julian Rembold. This is quite a piece of work. 

BMW claims an official average combined consumption of 8.2L/100km but the dash display was showing 9.9 at the completion of our 210km test, which included a mix of suburban, city and highway travel.

Our own figure, calculated from fuel bowser and tripmeter readings, came in slightly higher again at 10.5L/100km, which given our test vehicle’s two-tonne-plus weight and performance capabilities is still reasonable economy.

So, based on our figures, you could expect a realistic driving range of around 600km from its 65-litre tank, which prefers premium 98 RON petrol.

High numbers are what AMGs are about. Sadly that’s the case not only for performance outputs but also fuel consumption.

The official combined cycle fuel use claim for the C 63 S Coupe is 10.3 litres per 100 kilometres, and you need to fill it with 98RON premium unleaded fuel, too.

On test? Well, across a mix of different driving - urban, highway, back road and spirited stints - I saw an 'at the pump' return of 12.2L/100km, while the digital readout stated 12.0L/100km.

Given the performance on offer, and how much I took advantage of it during my week with the car, that’s not bad…

Fuel tank capacity is 66 litres. So go easy if you know there won’t be a fuel stop for a while.

First, the fun stuff. It certainly feels like ‘the ultimate driving machine’ when you slide behind the chunky leather-rimmed flat-bottom steering wheel and hold it in your hands.

The driver’s seat offers not only powered adjustment of backrest and base-cushion rake, but also four-way lumbar support and side-bolsters that can tighten their embrace of your upper torso to contend with high cornering loads.

There’s also manual extension of the base-cushion length for greater thigh support and a big left footrest to brace against, so you could not ask for a more accommodating and purposeful driving position.

The steering is perfectly weighted and the quartet of enormous disc brakes provide ample bite with superb pedal feel. Combined with its adaptive suspension and wide grippy tyres, the X3 is a family car that’s also invigorating to drive, particularly when you select the ‘Sport’ mode.

The enhanced engine response and sharper steering that result (even the instrument panel display changes) make any twisting mountain road an engaging experience, enhanced by an intoxicating exhaust note that only a BMW M six can deliver.

The turbocharged engine offers an unyielding surge of acceleration from well below peak torque at 1900rpm to maximum power at 5500rpm, making BMW’s claim of 0-100km/h in a scant 4.6 seconds sound credible.

You can also manually change gears using the steering wheel paddles, but we found the gearing and shift calibrations so good that we preferred to leave it in auto mode.

However, the X3 M50 has two distinct personalities, as in more relaxed drive modes it’s just as happy serving as practical family transport during the week for grocery shopping, daily school runs and other common tasks.

It’s also a comfortable tourer for family getaways, with long gearing that requires only 1500rpm to cruise at 100km/h where low engine, tyre and wind noise allow highway conversations at lounge room levels.

Just one word sprang to my mind when it comes to accurately describing the performance on offer from this car. The word is ‘brutal’.

Smash the accelerator and the power and torque on offer is enough to make your eyes feel like they’re not doing the right thing anymore. You get pushed back in your seat with a surge, and your ears are also rewarded with one of the best soundtracks in the automotive world. 

The engine builds pace with enormous intent, and the sound that comes from under the bonnet and out the back through the exhausts is addictive.

Yes, there is an active exhaust button which you have to press to make sure that you hear all that noise if you’re running around in 'Comfort' mode, and during my time with the car it was active the whole time.

I had some questions from neighbours over the week that I had this car about whether it was actually nice to live with on a day-to-day basis. And the answer is yes, if you put it in comfort mode it’s surprisingly amenable. 

The ride is really well sorted at pace despite having a bit of that trademark low-speed wobble that seems to afflict Mercedes products from A-Class through to the GLE SUV. But it wasn’t bad enough to really bother me, as most of my time was on highways and backroads.

The steering is direct and accurate. The only thing you need to be aware of is that you will lose traction at the rear axle when you put your foot down hard. And for the enthusiast that’s exactly what you want. 

I know I want to feel the thing squirm under throttle. It’s a rear-drive V8 coupe, after all. You want to feel like you’re a vein in its bicep muscle; you know, the one you see in a weightlifter’s arms – the one that wiggles around a lot. You want to have that. Right?

On the performance front it is exceptional. Twist the little dial on the wheel to 'Sport' or 'Sport+' (I didn’t sample 'Race' mode as I wasn’t at a racetrack), and everything feels like it’s had a protein shake.

Even so, in that mode it steers brilliantly, there's a nice feel through the wheel, and the ride, while stiff, controls the body brilliantly when you change directions. 

The transmission is very good, too. In Comfort mode it can take just a second or two at first to become accustomed to the idea that you want to drive aggressively.

But in Sport mode, or when you select the manual transmission mode using the trigger button on the steering wheel, you will certainly get the most out of the engine. That’s what I did when I was driving it in a ‘spirited’ manner.

If you are just after that high-end Coupe cruiser experience, it’s a relatively quiet car (provided the surface below isn’t the coarsest of coarse-chip bitumen), with enough luxuriousness to make it feel premium as well as sporty. That’s an important thing to consider, especially at this price point.

There is no applicable ANCAP crash test rating for the Mercedes C-Class Coupe, nor is there one for the C 63 specification. But when it was tested back 2014, the sedan scored five stars - as you’d expect.

It is comprehensively equipped in terms of safety technology, including auto emergency braking (AEB) with pedestrian and cyclist detection (from 7.0km/h to 70km/h) and it’s active for cars from 7.0km/h to 250km/h.

Plus there’s lane departure warning and active lane keeping assistance (from 60km/h to 200km/h), blind spot monitoring with 'Active Blind Spot Assist' that will stop you from veering into oncoming traffic, front and rear cross traffic alert, and adaptive cruise control (Distronic) with traffic jam assist.

The C 63 also features 'Route Based Speed Adaptation', which can adjust your speed based on where the car thinks you are on the map. Just note - if you’re driving through new tunnels that haven’t been flashed to your car’s nav (as happened to me in Sydney during my testing week) - then you could find the car dramatically braking for surface-level intersections. You can switch the system off, thankfully.

There are nine airbags fitted, and while you mightn’t use the rear seats much there are ISOFIX and top tether points for both positions (yes, only two).

It comes standard with a five-year, unlimited km warranty.

Scheduled servicing is determined by BMW’s vehicle monitoring system which advises when a service is needed, typically around 12 months/15,000km.

A capped-price servicing package covering five years/80,000km (whichever occurs first) totals $2475, or an average of $495 per service.

Mercedes-Benz is among the minority of luxury brands now offering a five-year/unlimited kilometre warranty plan - most still have three-year cover. So that’s a tick.

And the service intervals are pegged at 12 months/20,000km. Another tick.

Plus you can either pre-pay your service plan in three-year ($3800), four-year ($6000) or five-year ($6550) plans - roll it into the finance package, and it won’t hurt quite as much.

According to Mercedes, the three-year coverage option makes for a $900 discount over pay-as-you-go servicing.

Roadside assistance covers the five-year new car warranty period, too. So Mercedes seemingly takes good care of its customers. But if you have any concerns or questions over reliability, problems, issues or complaints about the C 63, check out our AMG C 63 problems page.