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M division aims its M5 super-saloon at unmatched heights. Does it hit the target?

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When appearing on the bootlid of a fast BMW, ‘CS’ originally stood for either Competition Sport or Club Sport – depending on exactly when it was applied, and to what. That might lead you to expect this week’s road test subject to be some stripped-out racing machine, but it isn’t.

The CS model suffix has, in fact, been used of late by BMW’s Motorsport in-house tuning division to identify all kinds of extra-special M cars, and now it’s being used on a ‘Club Sport’ model of a bigger and more powerful size altogether: the £140,780 BMW M5 CS super-saloon.

This feels like an M5 perfected rather than transformed. I like the way BMW has kept its core values in focus and addressed its key vulnerabilities, but I wonder if some will expect something more dramatic for their £140k

This car refines and enhances the mechanical recipe of the M5 Competition in a number of ways that may seem quite subtle on the face of it. Their aim, however, is to produce a performance car of very special status: the most powerful road-going BMW M car there has ever been, for one – but also the ultimate M5.

In that lofty pursuit, M division has resisted the lure of turning this car into some four-door track-day monolith and instead cherished and honoured the BMW M5’s enduring usability as a road car.

It has become such a habit of BMW to use later-model-life special editions to fully uncork the dynamic potential of its M cars that we predicted the appearance of this car in our 2018 road test of the current, F90-generation BMW M5. We wrote: “If BMW M history is any guide (think F10 M5 ‘30 Jahre’, F82 M4 CS and others), the very best version of this M5 may be yet to come. And when it does come, it ought to be something very special indeed.”

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Time to find out exactly how right we were.

The 5 Series line-up at a glance

Unlike the cut-down equivalents of rival brands, the BMW 5 Series derivative line-up still reads like a restaurant menu.

Even among lighter-touch performance models, there is both the M550i xDrive and the 545e to choose from. BMW doesn’t offer the non-Competition spec M5 in the UK any more.

 

DESIGN & STYLING

2 BMW M5 CS 2021 RT hero side

A good dose of exposed carbonfibre and a rather fetching new brightwork colour that BMW calls ‘gold bronze’ are the key material themes in the exterior design makeover of the M5 CS. The car has satin bronze-coloured kidney grilles and wheels; carbonfibre-edged air vents in its new bonnet and front bumper; and an all-new front splitter, boot spoiler, rear diffuser, and door mirror covers in carbonfibre, too.

BMW’s engineering changes have been driven by several aims, one of which is weight-saving. The CS’s carbonfibre-reinforced plastic (CFRP) bonnet, standard-fit 20in forged wheels, standard carbonceramic brakes, interior tweaks and a host of detail revisions have supposedly saved 70kg from the kerb weight of a stock M5 Competition.

Active stainless steel exhaust is claimed to conjure a bolder and more raw audible character for the CS than any F90-generation M5 has. Less sound-deadening in all quarters helps on that score

As we will explain later, it wasn’t a saving that amounted to much on our proving ground scales. But then the M5 CS isn’t some stripped-out circuit special like a BMW M4 GTS but a luxury performance car that comes fully loaded with digital technology and equipment.

The M5 CS has dampers introduced only last year on the BMW M8 Gran Coupé and it features retuned springs and anti-roll bar settings on both axles. Ride height has been cut by 7mm but, more important, BMW claims to have eliminated the “rapidly fluctuating wheel loadings” that could hamstring the ride composure and the limit handling of existing versions of the F90 M5 up to now.

The car’s engine is an overhauled version of the same 4.4-litre S63 eight-cylinder mill used in the regular M5, as well as in the previous M5 and in the X5 M and X6 M. In the new CS, it sits on the stiffer mounts of the M5 Competition but gains revised turbochargers and higher injector pressures than even that car had. A small additional front oil sump and a variable oil pump have been added to the engine’s package also, to prevent starvation should owners venture onto the track.

The revised V8 makes just 9bhp more than the M5 Competition has. Not much of a bump, you might think. But when, at 626bhp and 553lb ft, its peak outputs make the M5 CS the most powerful road-going BMW that there has yet been, they don’t seem like reasons for complaint.

INTERIOR

14 BMW M5 CS 2021 RT front seats

A host of little upgrades and performance-infused enhancements make quite a big difference to the cabin of the BMW M5 CS.

There’s a steering wheel with extra gloss black trim and Alcantara wrapped around its rim; some carbonfibre shift paddles; new red stitching for the car’s leather trim; one less storage cubby than in an M5 Competition (BMW has removed the armrest cubby to save weight and covered the gap with a fixed leather cover); and a ‘CS’ badge on the dashboard. The high-quality material feel of the G30-generation BMW 5 Series remains pervasive, though.

F90-gen M5 had round instruments with chrome bezels in 2018 but got octagonal digital instruments as part of last year’s facelift. We preferred the old ones.

This is the first M5 to use the new ‘M carbon’ lightweight front seats. They have a slightly different design and colour scheme from those we saw on BMW M3 and M4 Competitions earlier this year. However, the curious hard carbonfibre inserts to be found front and centre on the cushions remain. The seat positions you even lower at the wheel than in any other current M5, in a driving position that feels instantly special.

It’s dead straight, really low, superbly well supported and, despite the aggressive appearance of the bolsters, comfortable over extended use.

This wouldn’t be the ultimate M5 if BMW had compromised its full sized-saloon practicality, of course. Comfortable, adult-sized passenger accommodation is therefore afforded in the CS’s second row, although that comes in two, individually sculpted seats. This means the car is a strict four-seater (there’s no middle cushion and no fifth seatbelt) and it can’t be had with a folding rear seatback, even as an option.

The standard equipment level gives you digital instruments and a large colour head-up display, and between them you can select and configure exactly how much information you want to be broadcast so close to your eye line, and in what style. BMW’s M-specific display mode focuses and simplifies what is shown quite effectively, but even here there’s a hint of affected pizzazz about the layout of instrumentation, which could be clearer and simpler.

BMW M5 CS infotainment and sat-nav

You’d expect a very fulsome infotainment offering on a £140k M car – and BMW couldn’t have offered a much more generous one. Live Cockpit Professional, with a 12.3in touchscreen and BMW’s latest OS 7.0 software, is standard, as is a 12.3in digital instrument set-up, a good-sized M-specific head-up display, the enhanced Bluetooth phone system with wireless charging and wi-fi hotspot, and the Harman Kardon premium audio set-up.

The infotainment system is among the clearest and easiest to use on the market. It retains an iDrive-style physical input device, although you can issue it voice commands if you prefer. These are recognised with dependable accuracy once you’re familiar with the specific phrases it best knows, but navigating the system via the screen or the rotary wheel is often easier.

BMW’s Connected Package Professional is also included for free. This includes a data sim with the car for always-on networked services such as cloud-based navigation routing.

ENGINES & PERFORMANCE

24 BMW M5 CS 2021 RT bonnet

And so to that kerb weight. This may be the most powerful road car that BMW’s M division has made but, in as-tested form, it weighed precisely the same as the original F90 BMW M5 that we tested in 2018 (1940kg on the scales, fully fuelled). It also develops the same 553lb ft of torque as the standard M5 did (albeit over a broader band of revs). Could it be that much quicker against the clock?

Believe it. Whereas the standard car needed 3.3sec to hit 60mph from rest and 7.5sec to hit 100mph three years ago, the CS cuts the former to just 3.0sec and the latter to a faintly staggering 6.8sec. Our test car did that on Michelin Pilot Sport 4S tyres, it’s worth noting. On a warm set of the standard-fit Pirelli Corsas, there’s reason to believe it could go a tenth or two quicker over both measurements.

M5 CS is more supple and composed in its body movements than the regular M5 manages and it is remarkably agile and immediate in its responses for a car of its bulk.

Whichever tyre it’s on, then, this is a near-two-tonne, four-seat executive car that’s as quick as a supercar up to the national speed limit. It goes through a standing quarter mile at precisely the same prevailing speed as a Porsche Taycan Turbo S and would be travelling significantly quicker than the Porsche by the time a standing kilometre came up. It isn’t in every sense the very biggest-performing four-door on the planet, because there are a handful of rivals – both electric and piston-powered – with slightly greater firepower. But it misses that mark by a margin so small that you might well consider it completely insignificant and you’d be very unlikely to notice it on the road.

The M5 CS is nothing short of breathtaking in full stride. BMW’s updates to the engine manifest themselves in better mid-range throttle response than any current-shape M5 has had hitherto; an even freer power delivery right at the top of the 7200rpm rev range; and a noticeably more authentic-sounding, enticing audible character. Torque is produced in less of an elastic-feeling surge and in more accurate doses defined by the precise position of your right foot. And it keeps coming well beyond 6000rpm in a way that you still don’t find in too many turbocharged performance engines.

The accompanying V8 soundtrack is that little bit more raw than in even an M5 Competition, BMW having not only fitted that new stainless steel active exhaust but also removed sound insulation from all around the car, and also fitted a carbonfibre bonnet that evidently lets a bit more V8 noise out into the wild. You can hear more induction hiss when you first apply power, and then more turbine combustion howl as the revs rise, with matching audible drama coming from the bellowing exhausts behind you. Between them, those influences balance out BMW’s digital engine noise synthesis much more effectively here than in any other current M5, and they make for a markedly more likeable and genuine performance character for the car.

RIDE & HANDLING

26 BMW M5 CS 2021 RT otr front

BMW added its latest control regime for driving modes (which is marshalled via a grid-style touchscreen menu for its various suspension, steering, engine, driveline and electronic governance settings) as part of the M5’s mid-life facelift in 2020.

There’s a lot of choice to contend with among all of the options for configuration, needless to say. But your chances of finding and accessing particular combinations of settings that are to your taste, and that seem to prepare the car ideally for particular types of roads, weather conditions or styles of driving, are boosted enormously by BMW’s ‘M1’ and ‘M2’ toggle switches on the steering wheel hub.

The CS probably represents only a 10% gain to the grip level of an M5 Competition on perfectly smooth Tarmac, but on choppier surfaces it’s a much more composed car. Feels like a turning point for the F90.

You use these not only to save particular combinations of settings (with one long press), but also to dial them back up again really quickly and easily when you need it (with two short presses). And being able to do that feels like gradually bringing to heel the complexity of the car’s driving experience, and refining the character you want from the car, in a way that few of BMW’s rivals have yet mastered.

It helps, of course, that there is simply more to enjoy about this M5 than there has been about its F90 predecessor models. The CS’s suspension specification conjures much smoother and more settled vertical body control for it than a regular M5 Competition has.

Despite having less wheel travel than other M5s, the CS rides with more compliance and dexterity over bumps when you leave the dampers in their softest setting, staying level and composed over B-roads that would have made the regular car an excitable, hyperactive tussle.

Sport-mode suspension is usable on smoother roads, too, and brings in a real tautness about the body control, which is made all the more compelling by the improvement in steering feedback that you can perceive through the Alcantara steering wheel rim. Also, by the more predictable and benign way in which you can probe away at the adhesion level of the rear axle, and the angle of attack of the chassis, when you’re using the drivetrain’s 2WD mode.

At all times, the M5 CS’s handling feels truly agile and immediate, and finely balanced, given the car’s size and weight. An M5 Competition’s does, too, you might say. But the way the CS better communicates its limits, and feels so much better tied down and more consistently connected to the road surface, makes it a significantly more special driver’s car.

Track notes

On a circuit, there’s a super-linear, never-ending feel about the way the M5 CS’s engine hauls its way up through the gears, but there is real weight to the steering, and some body movement under hard braking and cornering, keeping you in touch with the physics going on around you.

The car much prefers smooth, deliberate inputs when you’re right on the limit. It’s remarkably controlled if you oblige it that way, but disturb its composure with steering input when braking, or try to haul it into an apex too suddenly, and it shows its weight.

It’s monumentally quick, though: the first saloon we’ve tested to go under 70sec on the MIRA dry handling track, no less. The carbon-ceramic brakes don’t have great initial bite but resist fade well. Our car’s Michelin Pilot Sport 4S tyres didn’t stand track use quite so robustly, overheating after five fast laps, even after a pressure bleed. Those with track use in mind would be well advised to take the standard Pirelli Corsas.

Comfort and isolation

There is a small price to be paid on cruising refinement for the extra driver focus of the M5 CS relative to other super-saloons, and to executive cars in a wider sense, but it’s not nearly so high as you might think.

This is a remarkably comfortable-riding car, considering its positioning. It’s smoother over bumpy, uneven B-roads than any other current M5 and only at all tetchy or aggressive-riding at low speeds, when bigger, sharper inputs work their way through its limited wheel travel. You could use it as a daily car just as easily as any other big, fast executive saloon, assuming your body is compatible with the shape of those sports seats (and only the heaviest of our test jury had any compliant about that at all).

The car’s noise levels do show the evidence of M division’s sound-deadening cull, though. While the regular M5 recorded in-cabin noise levels of 65dBA at 50mph and 68dbA at 70mph in 2018, the CS registered 69dBA and 73dBA respectively. The difference is noticeable and made up of a mixture of road roar and engine noise. It doesn’t make the CS hard to tolerate on a long cruise, but your passengers might want their headphones or earplugs in over longer trips.

MPG & RUNNING COSTS

1 BMW M5 CS 2021 RT hero front

BMW’s £140,780 asking price for the M5 CS is a lot to take in. It’s £20,000 more than BMW asked for the limited-run M4 GTS five years ago; and although it won’t be produced for very long, this car isn’t technically a limited-volume edition.

BMW won’t say how many units it’s importing to the UK, but it has confirmed that deposits have already been taken for all of the cars that are officially coming to the country, and that there’s a waiting list for any cancellations. There is some hope that M5 CS residual values could be much more encouraging than is typically true of fast-depreciating M5 super-saloons, then.

CAP expects M5 CS to hold its value slightly better than the much cheaper Mercedes-AMG E63, but worse than the Porsche Panamera Turbo S

BMW UK is offering the car in one, fully loaded equipment level that includes a head-up display, Laserlight LED headlights, M carbonfibre bucket seats and a Harman Kardon audio system for no extra charge. It comes in a choice of three colours (Brands Hatch Grey Metallic, Individual Frozen Brands Hatch Grey or Individual Frozen Deep Green), none of which incurs an extra cost, and with a choice of either gold or red brake calipers, again at no extra cost.

If you’re invited to buy one of these cars, then, your decision-making process could end up being simpler than you first realise.

 

VERDICT

28 BMW M5 CS 2021 RT static

The M5 CS is a mighty driver’s car produced with gimlet-eyed discipline. While rival players have become carried away in recent years with roll-cages and racing harnesses, BMW's M division has stayed true to the everyday versatility of its segment-defining super-saloon. Because if the ‘ultimate M5’ became any less usable than any other M5 on its way to its lofty pedestal... well, it would have lost something vital, wouldn’t it?

This extra-special M5 has lost almost nothing by way of good manners or usability. And compared with a ‘regular’, £101,000 M5 Competition, it has taken dynamic leaps – not just on outright performance but also for tactile feel, ride composure, handling sophistication and overall driver reward.

Jobs for the facelift? Don’t release one. The ultimate M5 should be a once-in-a-model- generation thing.

If there’s any disappointment, it’s learning that the ultimate M5 as M division has just defined it ought to be considered a discrete proposition rather than ultimate M car. Either a BMW M2 CS or M3 Competition makes a better track car, for instance. But when it comes to that sense of tyre-shredding muscle and titanic pace the modern super-saloon trades on, we can’t think of any rival available right now that has more to offer – or more still besides.

 

Richard Lane

Richard Lane, Autocar
Title: Deputy road test editor

Richard joined Autocar in 2017 and like all road testers is typically found either behind a keyboard or steering wheel (or, these days, a yoke).

As deputy road test editor he delivers in-depth road tests and performance benchmarking, plus feature-length comparison stories between rival cars. He can also be found presenting on Autocar's YouTube channel.

Mostly interested in how cars feel on the road – the sensations and emotions they can evoke – Richard drives around 150 newly launched makes and models every year. His job is then to put the reader firmly in the driver's seat.