What's all this about?

The BMW M4 CS. It stops a tantalising 'L' short of wearing the hallowed 'CSL' badging, but, to all intents and purposes, that's almost what this is: a harder, better, faster, stronger (and slightly lighter) M4. It is going to be built at the main plant in Munich in limited numbers between now and 2019, so get your order in quick if you want one. Because you will want one when you read the spec.

Haven't we already got a lot of M4 options open to us?

We have indeed, although the CS seems to herald an explosion in BMW M cars that can only be a Very Good Thing for petrolheads the world over. Currently, there's the 'halfway house' M Performance stable - think M140i, M240i, M550i xDrive and so on - for people who want a touch of BMW's tricolour magic, but without the intensity of driving experience or inflated cost of ownership. Then there are the 'regular' (we hate using this word, but we're going to have to, as you shall soon see) M cars, ranging from the M2 up to the X6 M. Finally, there are the Competition Packages for the M3, M4, M5 and M6, which firm up the suspension, add styling updates and throw in a bit of extra power for a modest fee.

What about the M4 GTS we saw last year?

Ah, that was an example of what BMW calls 'performance-maximising brand shapers'. The CS, though, fits between an M4 Competition Package and the GTS. And, if we're reading it right, BMW is planning to expand the whole M cars offering at all of the levels outlined above. So expect Competition Packages for the M2 and also the new M5 coming later this year; expect harder CS versions of the M2 and the M6; expect (maybe) lunatic be-winged brutes of extraordinary expense at the top of the M2, M5 and M6 trees. Hopefully.

So what's the M4 CS packing in terms of hardware?

Starting with the body and interior, carbon fibre is used for the bonnet, roof, the rear diffuser that's carried over from the M4 GTS and then also for the CS's specific front splitter and rear Gurney flap spoiler arrangement. The 19-inch front, 20-inch rear wheels are lightweight alloys that wear Michelin Pilot Sport Cup 2 semi-slick tyres as standard (look back to the E46 M3 CSL for a reference point), although optional Michelin Sport road tyres can be fitted for no extra cost. The brakes are M compound items gripped by four-pot front, two-pot rear callipers and at the back are Organic Light Emitting Diode (OLED) light clusters.

Inside, great swathes of Alcantara make the CS feel very different to a normal M4. The sporty fabric clothes bits of the lightweight M sports seats, the steering wheel and much of the dash, where there's an embroidered 'CS' logo to help ram the 'special M4' ideology home. The door cards are made of compacted fibres and feature door pulls that are loops of material finished in the tricolour war paint of M Division. Climate control, BMW HiFi Professional and Navigation Professional are all part of the standard equipment of the M4 CS.

And underneath that carbon-fibre bonnet?

The same 3.0-litre, twin-turbo, straight-six petrol engine as found in any M4. It makes 460hp and 600Nm in the CS, which compares well to the rest of the family: a regular M4 has 431hp/550Nm, the M4 Competition Package has 450hp/550Nm and the M4 GTS had 500hp/600Nm. Performance for the M4 CS is blistering, as it will do 0-62mph in 3.9 seconds and run on to a top speed of 174mph, thanks to the M Driver's Package as standard. BMW also says it has trimmed a colossal 14 seconds from the 7m 52sec Nordschleife lap-time of a regular M4, posting a scintillating 7m 38secs round the fabled Green Hell. It achieves this courtesy of uprated chassis hardware.

Such as?

The firmer suspension set-up of the M4 Competition Package helps, as does a standard-fit seven-speed M DCT twin-clutch gearbox with Drivelogic. The M4 CS comes with bespoke-tuned Adaptive M dampers as standard and it has an Active M Differential, M Dynamic Mode (MDM) and Dynamic Stability Control (DSC), which - coupled to those super-sticky tyres, carbon-fibre body addenda and powerful brakes - gives the newcomer all the edge it needs.

And what's the fuel economy like?

Are you serious? Oh... you are serious. OK, not much different to standard: 33.6mpg and 197g/km CO₂ for the CS, plays 34mpg and 194g/km CO₂ for a 431hp M4. Happy now?

Yes, thanks. Can you give me an idea of pricing?

It's £89,130 on-the-road, which doesn't make this sort of brilliance exactly cheap - but then, the M4 CS is a very special car. Best news is (well, for us anyway...), we'll be driving it in just a few weeks' time, so we'll report back to you then.

Matt Robinson - 19 Apr 2017