On the face of it, the 2021 BMW M5 CS made very little sense whatsoever. Here was an attempt to sharpen up and button down the F90 M5, the heavy and luxurious four-door flagship of the M car range. It was very good at that already, probably superior to all the alternatives, so why meddle with the recipe? Moreover, the CS upgrade made a car already infamous for its fierce depreciation more expensive still - who would be willing to lose their shirt on a £140k 5 Series with Covid mayhem still so recent?
It was also a car proclaimed to be the most powerful M car in history, despite being just 10hp stronger than the 625hp M5 Competition which cost tens of thousands less. Soon after the CS was surpassed to that honour by the XM of all things. Fans have needed no further ammunition when it’s come to BMW making odd decisions, and the M5 CS seemed like a very curious move indeed. What was the point?
The point, as it turned out, was to make one of the all-time M car greats - and, by extension, a super-saloon for the ages. Plaudits came flooding in during 2021, up to and including car of the year titles, praising the CS for pretty much every facet of its dynamic make-up. This was by no means merely an M5 with a few extra horsepower and some blingy wheels; it was something much, much more special. In truth, we didn’t need a reason to drive the car again, given how limited (and how impressive) that initial exposure was. But in 2023 the F90 has some additional significance: the M3 equivalent is now out (and seemingly just as awesome), there’s an M2 in the works, and the next M5 with its plug-in powertrain will be here before we know it. As the high watermark for both the M5 and the CS M car, it only seemed right to reassess it in the light of pending all-time hero status.
Firstly, that the M5 is as handsome as it is feels worth highlighting. Mostly because in 2023 we're used to pillorying BMW for its design choices, so it’s nice to play a different record for a change. But also because the CS really does elevate what is a reasonably plain-Jane M5 into a properly arresting four-door saloon. Of course, gold accents do tend to draw the eye, but then you’ll clock how purposefully the CS sits on its wheels, the tracks and arches filled out properly and its haunches bursting with attitude. The grille surrounds are as naff as the yellow Laserlights are brilliant. And Frozen Deep Green Metallic must rank up there with Laguna Seca Blue and Techno Violet as one of the great M colours. Even to the uninitiated, the M5 CS just looks right.
There are certain attributes always focused on when it comes to driving an M car. The engine will be key to the experience, of course, as will its ability to do lurid powerslides. That’s why we love a modern M car, right? And while the CS can fairly emphatically tick both those boxes given the time, space and denial, the fact that neither stands out as the best bit speaks volumes of the achievement here. It can punch as hard and skid as naughtily as anything with the M tricolour, but there’s so much more to it than that. And they’re pretty persuasive elements on their own…
Officially, the CS was 70kg lighter than an M5 Competition, with standard ceramic brakes and forged wheels. The ride height was said to be 7mm lower, with dampers ‘developed for the M8 Gran Coupe’. The tyres were a bespoke Pirelli P Zero Corsa, and the CS got its own engine mounts. The modifications didn’t point to a transformative overhaul, yet that’s exactly what was delivered. And let’s be clear: the M5 Competition was - still is - a very good super-saloon, one of the best around.
Only the CS was better, and in every single regard. Sharper to drive while also being more comfortable; better suited to track driving while still the consummate cruiser; no more demanding yet considerably more exciting. The CS was proof, amid all the distractions, that nobody makes a fast four-door quite like BMW M. ‘A luxury saloon equally at home on the road as it is on the racetrack’ sounded like the usual press release fluff, until driving it. The best of both worlds was possible.
This CS feels even better than it did in 2021. Partly that’ll be down to more than 20,000 miles now recorded, the whole car bedded in and - excuse the bluntness - seeming really sodding fast. As with so much of the CS, the powertrain feels more than the sum of its parts - that sum being 635hp and 553lb ft, remember. Perhaps BMW’s claims for the engine mounts - a firm connection between motor and structure ensuring ‘rapid engine response and immediate transmission of its power to the drivetrain’ - ring true here, the additional urgency and response stronger than just another 10hp would have you believe. That this car takes a third of a second (or very nearly 10 per cent) from the Competition’s 0-62mph time - 3.0 seconds against 3.3 - with such a nominal boost indicates what we’re talking about. This BMW is insatiably quick.
The tyres make a difference this time around as well. On that first drive, it was using a Michelin Pilot Sport 4S; undoubtedly a very good tyre, but not the Pirelli P Zero Corsa the car was designed around and can now be found on each corner. Any reservations that existed in 2021 can now be quashed: the CS is sensationally good.
The chassis tweaks have created a large, heavy four-door car that’s willing to be driven in whatever fashion you desire, and it’s brilliant doing any of them. It can do slow in and fast out like the very best M cars, torque immense and xDrive perfectly judging grip and slip from your inputs. The front end is sufficiently precise (and the brakes so mighty) that this big 5 Series can be stood on its nose and clipping points nailed every time. Or it’s just as easy to establish a less intense flow between bends, guide it with barely any effort but unflappable confidence as every single input finds the perfect output. Seldom has a car this large, potent and valuable been so calming as well, but that’s what such unshakeable faith will do. It doesn’t take long to drive it like a smaller, lighter car, because that’s exactly how it behaves. With what feels like almost 700hp.
Nothing appears to tax the CS, such is its composure and resolve, yet the ability is not at the expense of engagement - this is not another all-conquering yet aloof performance car. Those seats plumb you into the action that much more intimately, the turbo V8 has more of a voice, the steering - no doubt thanks to less weight, both sprung and unsprung, upfront - a model of clarity against a Comp. By perfectly treading the line between additional involvement without introducing unwanted compromise, BMW M created an icon. This is no more taxing than a regular M5 to use every day, yet not a mile will pass where it doesn’t feel tangibly more special. It’s the trick pulled off by Porsche GT sports cars and very seldom seen elsewhere.
No Hero is perfect, mind. And before this writer is accused of more BMW bias, it’s worth pointing out a couple of the M5’s less-than-stellar attributes. Though the CS boasted a sports exhaust and M Sound Control - offering ‘a distinctive M-specific sound that accentuates the engine’s strong production of power and appetite for revs’ - both Audi and AMG deliver more stirring V8s. It’s always a bit too smooth to feel authentic, then overly muted with the exhaust button off and overbearing with it on. Plus there’s maybe just a tad more noise from those Pirellis than is desirable for such an adept mile muncher. But that’s really nitpicking. And seems a more than reasonable price to pay for what else is on offer.
Which brings us to that other CS stumbling block - it’s a heck of a lot of money. Now more than ever, in fact, because those Competitions have done what M5s have always done and depreciated while the CS has steadfastly clung to its value. It launched at basically £40k more than standard, or £20,000 more than an Ultimate Packed M5; now a standard car can be bought for less than half the money of a comparable CS. And that’s a huge amount of money.
But where a Competition will continue to lose money, it seems unlikely that the CS will, such is the venerated reputation already established, the tiny numbers - fewer than 100 were sold in the UK - and its status as final purely V8 M5. Much like those Porsche GTs mentioned earlier, it feels like the CS will continue to be worth a lot as those ordinary models seemingly little slower on paper become more affordable. It deserves to. As the future looms, the driving experience is destined to be more important than any number written on the page. There’s no better evidence of that than this sensational M car - making no sense whatsoever has never been so hugely compelling.
SPECIFICATION | BMW M5 CS
Engine: 4,395cc, V8, twin-turbocharged
Transmission: 8-speed auto, all-wheel drive
Power (hp): 635@6,000rpm
Torque (lb ft): 553@1,800-5,950rpm
0-62mph: 3.0 seconds
Top speed: 189mph
Weight: 1,825kg (DIN, without driver, 1,900kg EU)
MPG: 25-25.5
CO2: 253-258g/km
Price: £140,780
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