BMW M4 vs Mercedes-AMG E63

What's the difference?

Brutal, bruising and utterly brilliant, the M4 CS will be an acquired taste due to its no-compromise approach, but those willing to take the leap will find a performance car like few others at their disposal.

The E 63 S fills its niche in AMG's Australian line-up perfectly. More mature than the brand's four-cylinder hatches and SUVs, but not as overbearing as some of its bigger sedan, GT and SUV stablemates. And its ability to seamlessly switch between serene comfort and dynamic performance has nailed the objective for this 2021 update.

The M4 CS is familiar in all the right ways, but definitely looks significantly jacked up compared to its lesser siblings.

Part of that is the extensive use of carbon everywhere, from its bonnet panels to its roof, front lip, side skirting and boot spoiler. But also because of its super-muscular angles and creases, including the huge dome in its bonnet.

Also exclusive to this M4 CS is the light treatment, with the front LEDs lighting up with yellow highlights the brand says are supposed to be reminiscent of GT racing cars.

At the back, the rear lights are flush with fibre optic lighting, lending a flowing and unique light signature that looks epic at night.

Inside, it's a sea of carbon, with the lightweight racing seats, the dash inserts and the centre console all lined in it. It is a perfectly finished space, though, and one that's also flecked with red, including a 12 o'clock band on the thick-rimmed steering wheel, the seat backs, the contrast stitching and the paddle shifts.

Be warned, though, it takes some acrobatics to climb into or out of the CS. The seat bottoms have these super high edges that double as grab handles, but require some awkward contortions to navigate.

In short, it looks angry, this M4 CS, inside and out.

The E 63 S has been massaged for 2021 starting with flatter headlights, AMG's now signature 'Panamericana' grille, and a high gloss black flap across the top of the curved 'Jet Wing' section defining the lower part of the nose.

At the same time, the vents on either end of it are larger and feature twin transverse louvers to guide cooling air to wherever it's needed.

It's all about what AMG calls 'optimised aerobalance' but the form is just as appealing as the function. The characteristic 'Power Domes' in the bonnet dial up the muscle, as do the fat wheel arches (+27mm each side), and 20-inch rims with distinctive aero inserts.

This car's optional exterior carbon package consists of a front splitter, side sills, a flash near the fender badges, the exterior mirror covers, the boot lid lip spoiler, as well as the lower apron around the redesigned diffuser and quad tailpipes.

New, intricately styled LED tail-lights are also flatter, but there's even more going on inside.

A new AMG sports steering wheel features three rounded twin-spokes with new switches on the bottom to control the car's dynamic set-up.

It also picks up a new take on the small touch-sensitive controllers used to adjust the instrumentation and manage other functions like phone calls, audio and the cruise control.

Not sure I'm in love with them at this stage. In fact, the words fiddly, imprecise, and frustrating come to mind.

Nappa leather covering the superb AMG sports seats, upper dash, and door beltlines remains standard, but the show-stopper is the 'Widescreen Cockpit' - twin 12.25-inch digital screens for the MBUX multimedia interface on the left and instruments on the right.

The instrument cluster can be set to 'Modern Classic', 'Sport' and 'Supersport' displays, with specific AMG read-outs such as engine data, gear speed indicator, warm-up status, car set-up, as well as a G-meter and 'RaceTimer.'

To borrow an official automotive design term, it looks schmick. Overall, with touches like open-pore black ash wood trim, and brushed metal highlights, the interior looks efficient but classy, with an obvious attention to detail in the layout and its execution.

It all boils down to how you classify practicality in a car like this. I mean, the basic stuff is all there – it's got two doors, four seats and a boot capacity of 440 litres.

It measures 4801mm in length, 1918mm in width and 1399mm in height, and room for front seat riders is good, but less so for anyone you squeeze into the back. There are even ISOFIX points for a child seat.

But if you consider practicality the practical pursuit of performance, then the M4 CS has plenty of perks.

At just under 5.0m end-to-end the E-Class sits in the upper range of the mid-size luxury spectrum. And almost 3.0m of that is accounted for by the distance between the axles, so there's plenty of space inside.

The driver and front passenger are provided with heaps of room to breathe, and there's a surprising amount of space for those in the back as well.

Sitting behind the driver's seat set for my 183cm (6'0”) position I had more than adequate head and legroom. But access to and from the back is a struggle for full-size adults.

The rear doors open out a long way, but the limiting factor is the size of the aperture, necessitating excessive contortion of the head and limbs to fold in and out of the car.

Connectivity runs to two (power-only) USB-C sockets in the front centre storage bin, as well as another USB-C (for power and multimedia) and 12-volt power outlet in the centre console.

Speaking of the front centre storage bin, it's a decent size and has a padded split lid so it can double as an armrest. There are two cupholders in the front console, a generous glove box, as well as long door compartments with recesses for large bottles provided.

There's a pair of USB-Cs along with another 12-volt socket in the back, sitting under the climate control panel with adjustable vents in the rear of the front centre console. Nice.

The fold down centre armrest incorporates a lidded (and lined) storage box as well as two pop-out cupholders. Again, there are bins in the doors with room for smaller bottles.

The boot offers 540 litres (VDA) of volume, and is able to swallow our three-piece hard suitcase set (124L, 95L, 36L) with room to spare, or the substantial CarsGuide pram, or the largest suitcase and pram combined! There are tie-down hooks to help secure loads, too.

Don't bother looking for a spare of any description, a repair/inflator kit is your only option. And the E 63 S is a no-tow zone.

So, first of all, let's get the price out of the way. At $253,900, before on-road costs, this car's competitive set is a bruising, all-German trio comprising the Audi RS 7 Sportback ($224,000), BMW M5 Competition ($244,900), and Porsche Panamera GTS ($309,500).

And no surprise, it's loaded with all the luxury features you'd expect in this part of the market. Here are the highlights.

On top of the standard performance tech and safety equipment fitted to the E 63 S (covered later in this review), you'll also find: Nappa leather trim (seats, upper dash, upper door cards, and steering wheel), MBUX multimedia (with touchscreen, touchpad, and 'Hey Mercedes' voice control), 20-inch alloys, three-zone climate-control, interior ambient lighting, auto LED headlights (with 'Active High Beam Assist Plus'), eight “energising comfort programs” (with 'Energising Coach'), an 'Active Multicontour' front seat package, the 'Air Balance' package (including ionisation), and keyless entry and start.

Also included are the the 'Widescreen' digital cockpit (twin 12.25-inch digital screens), 13-speaker Burmester audio with digital radio, Apple CarPlay and Android Auto, a panoramic sunroof, adaptive cruise control, a head-up display, augmented reality satellite navigation, 'Parktronic' self-parking, electric front seats, seat cooling and heating front (heated rear), heated front centre armrest, a power-adjustable steering column, auto rain-sensing wipers, a wireless device charger, illuminated door sills, as well Amazon Alexa, etc, etc, etc.

And our test car also featured a couple of tasty options. An exterior carbon package ($7500), and AMG's professional grade ceramic composite brakes ($15,900), for an as-tested price of $277,300.

BMW has found yet more grunt lurking in its trusty 3.0-litre 'M TwinPower' six-cylinder petrol engine, with the M4 CS now pumping out 405kW and 650Nm.

That's a decent jump from the 390kW and 620Nm served up by the M4 Competition, and a giant leap from the outputs of the 'base' M4 – 353kW and 550Nm.

Predictably, then, the CS is the fastest of the lot, knocking off the run from 0-100km/h in 3.4 seconds, compared to 3.5 and 4.2 in the Competition and M4, respectively. The top speed is also dialled up to 302km/h.

All that power is channeled through an eight-speed automatic and sent to all four wheels on demand, with the help of an 'Active M Differential'.

The E 63 S is powered by the M178 version of the all-alloy 4.0-litre twin-turbo V8 engine used across numerous AMG models from the C-Class up.

Thanks in no small part to direct injection and a pair of twin-scroll turbos (located in the engine's 'hot vee' to optimise throttle response), this all-alloy unit produces 450kW (that's 612hp) from 5750-6500rpm, and 850Nm from 2500-4500rpm.

And as per standard AMG practice for its Vee engines, this car's powerplant was built from scratch by a single engineer in Affalterbach. Thank you Robin Jäger.

AMG calls the nine-speed transmission used in the E 63 S an MCT, which stands for Multi-Clutch Technology. But it's not a dual-clutch, rather a normal auto transmission using a wet clutch as opposed to a conventional torque converter, to connect it to the engine on take-off.

Drive goes to all four wheels via Merc's '4Matic+' AWD system, built around an electromechanically controlled clutch connecting the permanently driven rear axle (with locking diff) variably to the front axle.

The M4 CS is fitted with a 59-litre fuel tank, which – given the BMW's official fuel claim of 10.2 litres per hundred kilometres – should deliver a driving range on a full tank of 541 kilometres.

But... BMW also says the regular M4 – you know, the one that makes 52 fewer kilowatts and 55Nm less torque – uses 10.1L/100km, so do with that information what you will.

Claimed fuel economy for the combined (ADR 81/02 - urban, extra-urban) cycle is 12.3L/100km, the E 63 S emitting 280g/km of CO2 in the process.

That's a pretty hefty number, but in line with this car's proportions and performance potential.

And Merc-AMG has gone to great lengths to minimise fuel use. As well as the standard 'Eco' stop-start function, in the 'Comfort' drive program cylinder deactivation becomes active, the system able to drop four cylinders anywhere between 1000 to 3250rpm.

There's no physical hint of half the cylinders leaving the party. The only clue is a blue icon on the dash indicating a temporary shift to V4 operation.

Despite all that effort, however, we saw a dash-indicated 17.9L/100km over a mix of urban trundling, highway cruising, and some spirited dynamic assessment.

Recommended fuel is 98 RON premium unleaded (although it'll run on 95 at a pinch), and you'll need 80 litres of it to fill the tank. That capacity translates to a range of 650km according to the factory claim, and 447km using our real world result.

The hardest and angriest M4 of all time is, perhaps unsurprisingly, hard and angry. This is a race track specialist, but because I don't happen to own one of those, my first experience with the barking (and barking mad) M4 CS was navigating my way back from BMW's inner-city dealership.

Like it or lump it, you're going to read some Porsche comparisons here, because you're talking not too far off base 911 Carrera money, and suddenly I find the two Germans doing battle for a spot in my dream garage.

First things first, the BMW won't be much chop for daily driving for most people. Happily, I have a sickness for uncomfortable sports cars. It tells me that no compromises have been made in the pursuit of punishing performance.

A good thing, too, because the BMW, at city speeds, can be punishing. Everything feels heavy, the seats aren't overly comfortable – especially the hard bits that tend to dig in when cornering – and it stiff-arms its way over road imperfections, that exhaust booming and barking as it does.

Again, I loved it, and you probably will, too. But it's still not the kind of car I'd relish sitting in the morning peak hour rush in.

But escape the confines of the city and the BMW M4 CS suddenly makes a whole heap of sense. The acceleration is genuinely brutal, and wonderfully theatrical, with that quad-tipped titanium exhaust barking and snarling as you rocket towards 100km/h.

The steering is brilliant, with feedback fed to your wrists via that thick-rimmed wheel, and the entire experience feels sharp, super engaging and edgy.

You can push the M4 hard and fast, and I'm certain my limited talents would run out far before the BMW's would, but there's this thrilling sense of peril sparked by the aggression of the experience, that I love.

It's like the magic of a roller-coaster, I guess. Even if you know nothing is going to happen, you never really know, right? And in that lies the magic.

But back to original question, this or a Porsche 911? There's no doubt a Carrera is a better all-rounder, in terms of comfy commuting and race track fun, but this angry M4 is all shouty theatrics, all of the time.

I bloody love it.

AMG's major goal with this upgrade of the E 63 S was to maintain its dynamic response and ferocious performance, but dial in the extra comfort customers had said they wanted.

So, the 4Matic+ AWD system has been fine-tuned for more smoothness as has the Comfort option in the dynamic set-up. But we'll investigate that shortly.

First, that 4.0-litre turbo V8 in the nose is claimed to slingshot this roughly 2.0-tonne sedan from 0-100km/h in just 3.4 seconds, and it feels every bit that fast.

With 850Nm available from 2500-4500rpm and nine gear ratios to help keep you operating in that Goldilocks band, mid-range thrust is monumental. And thanks to the bi-modal sports exhaust it sounds beautifully brutal.

The nine-speed auto's wet clutch, as opposed to a conventional torque converter, is designed to save weight and optimise response. And while some will tell you an auto with one input shaft is never going to be as fast as a dual-clutch with two, shifts are rapid and direct. The wheel-mounted shift paddles are larger and set lower, as well.

The AMG 'Ride Control+' suspension with multi-chamber air suspension and adaptive damping is amazingly good. The underlying set-up is by multi-links front and rear, and despite riding on big 20-inch rims wrapped with low-profile, high-performance Pirelli P Zero rubber (265/35 fr - 295/30 rr) the Comfort setting is incredibly... comfortable.

Slip into 'Sport' or 'Sport+' and the car immediately feels tauter but far less compliant and forgiving. An impression reinforced by the engine, transmission, and steering shifting to a more buttoned-down mode at the same time.

The standard dynamic engine mounts play a big part here. Able to make a soft connection for maximum comfort, but switch to a rigid link when required.

But no matter which mode you're in, the car is well damped and feels beautifully balanced in quick cornering. And the E 63 S's electro-mechanically-assisted variable-rate steering is progressive, feelsome, and accurate.

The 4Matic+ AWD system is built around an electromechanically controlled clutch connecting the permanently driven rear axle (with locking diff) variably to the front axle.

Torque distribution happens imperceptibly, the big V8 putting its power down emphatically, with various electronic systems tieing up the loose ends as you aim up for the next corner.

 There's even a 100 per cent RWD Drift mode available in the Race setting, but without a race circuit at our disposal this time around that'll have to wait for another time.

The optional ceramic brakes feature huge rotors and six-piston front calipers, and stopping power is immense. And the good news is they operate quickly but progressively at normal pottering around town speeds. No warming up required to get them in an optimal temperature zone (as can be the case with other ceramic set-ups).

The three-pointed star's white-coated boffins have gone to town on the E 63 S, and the car is as good as it currently gets in terms of active and passive safety technology.

You could argue this car's dynamic ability is its strongest contributor to crash-avoidance. But a broad suite of features, specifically designed to keep you out of trouble includes, forward and reverse AEB (with pedestrian, cyclist, and cross-traffic detection), traffic sign recognition, 'Attention Assist', 'Active Blind Spot Assist', 'Active Distance Assist', 'Active High Beam Assist Plus', 'Active Lane Change Assist', 'Active Lane Keeping Assist', and 'Evasive Steering Assist.' That's a lot of assists.

There's also a tyre pressure monitoring and pressure loss warning system, as well as a brake priming function (monitors release speed on the accelerator pedal, moving pads factionally closer to the discs when required), and brake drying (when the windscreen wipers are active the system periodically applies just enough brake pressure to wipe water off the brake rotors to optimise wet weather efficiency).

But if an impact is unavoidable the 'Pre-Safe Plus' system is able to recognise an imminent rear-end collision and fire up the rear hazard lights (at high frequency) to warn following traffic. It will also firmly apply the brakes once the vehicle is stationary to minimise the risk of whiplash injuries if the car's then hit from behind.

If the potential crash is coming from the side, 'Pre-Safe Impulse' inflates air chambers in the side bolsters of the front seat backrest (within a fraction of a second) moving the occupant to the side towards the centre of the car, away from the impact area. Amazing.

As well as that, there's an active bonnet to minimise pedestrian injuries, an auto emergency call function, 'Crash Response Emergency Lighting', even a first aid kit and hi-vis vests for all occupants.

For the record, the current E-Class received a maximum five-star ANCAP assessment in 2016.

The M4 CS is covered by BMW's five-year, unlimited-kilometre warranty, with condition-based servicing available in packs, which will cost you $3530 over five years/80,000km, or $2900 over four years/60,000km.

All AMG models sold in Australia are covered by Mercedes-Benz's five year/unlimited km warranty, with 24-hour roadside and accident assistance included for the duration.

Recommended service interval is 12 months or 20,000km, with pricing for a three-year (pre-paid) plan set at $4300, a $950 saving overall relative to its three year, pay-as-you-go 'Service Solutions' capped price program.

And if you're happy to fork over a little more up-front, there's a four-year service deal at $6300, and five years coming in at $7050.