KTM X-Bow vs BMW M4

What's the difference?

Okay, so rain is not your friend. Neither is brutal sunshine, strong winds or any speed bump anywhere. There are probably a handful of times you'll want to drive it, and when you do you will definitely get hit in the face with rocks and bugs, and spend most of your time wondering just how the hell this thing is legal.

And yet, we are hopelessly, head-over-heels in love with it. It's an absolute weapon on a track, a joy on anything even resembling a twisting road and it is one of the few genuinely unique cars on the road today. And the fact it exists at all is a cause for absolute celebration.

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 X-Bow R is built for purpose in the most wonderful of ways. From the visible suspension components to the rocket-style exhausts, to the stripped-bare interior, it's fairly obvious that form came a distant second to function in the X-Bow's design process.

And, for us at least, that's a tremendous thing. It looks raw and visceral, and a bit like Harvey Dent post-fire - you can see all the normally hidden components doing their thing. It's mesmerising.

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.

Short answer? It's not. People are unlikely to test drive an X-Bow R and start looking for cupholders and storage space, but if they did, it wouldn't take long.

Aside from the twin seats, a four-point racing harness, a high-mounted gearshift, a pull-lever handbrake, and detachable steering wheel, the cabin is as bare as Old Mother Hubbard's cupboard.

Luggage space is limited to what you can carry in your pockets (though wearing cargo pants will help) and even getting in and out of the thing takes some fleet-footed antics. With no doors you need to literally jump in. And the side sills are only rated to 120kg, so heavier types will need to avoid stepping on them at all, and instead attempt a kind of running leap into the cockpit.

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.

We're talking a $254,900 entry price for the M4 CS, which – despite my attempts at justification – is a lot. Remember, the regular M4 is $168,700, and the M4 Competition is $186,500, so we're talking a sizeable premium here.

BMW justifies that price increase in two ways. The first is scarcity, with the M4 CS limited to just 50 examples in Australia. And the second is by dialling up every aspect of the M4's performance to terrifying levels.

The engine outputs are up, the weight is 20kg down, there are better brakes, better seats, a louder exhaust, a stiffer chassis – it goes on and on.

We'll get to some of the performance stuff in a moment, but here's what else your money buys you with the M4 CS.

It starts outside with staggered alloys, 19-inch up front and 20-inch at the rear, wrapped in track-ready rubber. There's also hi-po 'M Compound' brakes with red calipers, lightweight carbon racing seats that are heated up front, an Alcantara-trimmed steering wheel, the 'M Carbon' exterior package with carbon bonnet and roof, adaptive 'M Suspension' and a titanium exhaust that howls like the winds of hell.

The less performance-focused stuff is similar enough to the other M4 models including a 12.3-inch centre screen with digital radio, Apple CarPlay and Android Auto, a second 14.9-inch screen that handles your driving data and a head-up display. There's also twin-zone climate control, Merino leather upholstery and ambient interior lighting.

But all of that is secondary, really. This is about performance, specifically of the brutal kind.

The X-Bow R's power comes from an Audi-sourced, turbocharged 2.0-litre engine, paired with a VW Group six-speed manual transmission (and one of the stubbiest gearsticks in existence). That mid-mounted marvel produces 220kW at 6300rpm and 400Nm at 3300rpm, and ships it off to the rear tyres with the assistance of a Drexler mechanical limited-slip differential.

Thanks to its lithe and lightweight body, that's enough to propel the X-Bow R from 0-100km/h in a blistering 3.9 seconds, and on to a top speed of 230km/h.

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'.

KTM lists the X-Bow R's claimed/combined fuel figure at 8.3 litres per hundred kilometres (though we were managing mid-12s after an, ahem, very spirited test), with emissions pegged at 189 grams per kilometre.

The X-Bow R is also fitted with a 40-litre fuel tank, accessed via a side-mounted inlet. Instead of a fuel gauge, expect a digital reading showing how many litres you have left.

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.

It couldn't be more Fast and Furious if it had Vin Diesel growling under its (non-existent) bonnet. We have technically driven faster cars, but we have never driven anything that feels quite so fast as this utterly insane X-Bow R.

Climb in, strap into the four-point harness and select first via the surprisingly easy-to-manage gearbox and clutch set up, and, at slow speeds, wrestle with the dead weight of the completely unassisted steering, and it's immediately clear that this is a driving experience like nothing else currently road-legal in Australia. Even at walking pace, the X-Bow R feels poised for an assault on the future, and it attracts attention on the road like nothing else we've ever driven.

Its road-scraping ride height and diminutive dimensions make tackling traffic an intimidating prospect, with regular hatchbacks suddenly taking on truck-like proportions and actual trucks now looking like passing planets. There's a constant concern that you're sitting well below the traditional blind spot, and that you could be crushed at any moment.

Combine all that with the bad weather that cursed our final day of testing, and the X-Bow R is all sorts of watery hell. It is truly homicidal in the wet, too, with the back end breaking grip at the slightest provocation. And the turbocharged 2.0-litre offers plenty of that.

But on a sunny day, and on the right road, it's pure driving bliss. The acceleration is brutal, the grip endless and the Audi sourced gearbox an absolute treat. And it pulls in every gear, tackling 35km/h corners in third and absolutely blasting out the other side.

Cornering is scalpel sharp, and the steering - so heavy at slow speeds - is light and efficient at pace, requiring only the most minuscule of movements to bite into a bend.

It is anything but perfect in the city, and even a light sprinkling of rain will have you seeking shelter (and a refund), but on the right road, on the right day, there are few if any cars that offer the kind of razor-sharp thrills and intoxicating excitement of KTM's monstrous X-Bow R.

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.

Expect no ANCAP rating here, I'm afraid. But the BMW 4 Series does wear a five-star rating from 2019.

The M4 CS gets six airbags (driver and passenger, side airbags, head airbags), along with what BMW calls its 'Driving Assistant Professional', which bundles active cruise control (with stop and go function), front and rear cross-traffic warning, 'Steering & Lane Control' and 'Lane Keeping with Side Collision Warning'.

The X-Bow R is covered by a two-year, unlimited-kilometre warranty, and while service prices aren't capped, Simply Sports Cars estimates an average serve cost at about $350.

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.