Not as extreme as the GTS, the BMW M4 CS is the best F82 M4 to date, with a chassis that can be enjoyed and exploited
The BMW M4 should be the very essence of evo. Front-engined, rear wheel-drive and with enough power and torque from its turbocharged straight six to offer a perfect balance between brilliant and challenging. Unfortunately, the M4 has always been more challenging than brilliant, struggling to deploy that power and torque cleanly and smoothly through its rear tyres thus robbing the driver of one of BMW’s ultimate driving experiences.
Which brings us to the M4 CS, a lighter M4 with more performance and a chassis and steering set-up that has been optimised to get the best from the whole package. The big question is, has BMW finally created the car the M4 should have been from its launch?
Taking the lower and stiffer springs, dampers and anti-roll bars from the M4 Competition Pack, the only other hardware changes made to the M4 CS is the fitment of 265/35 ZR19 at the front and 285/30 ZR20 at the rear fitted to lightweight forged wheels. Wrapped with Michelin’s track orientated Pilot Sport Cup 2 tyre (Pilot Sport 4 tyres are available as a no cost extra) the work of Frank van Meel and his team was focused on tuning the CS’s chassis to get as much from those tyres as possible.
To this end, both the M Adaptive Dampers and the electronic power steering have been reprogrammed to suit the tyre’s characteristics. Those front tyres were chosen to improve the car’s steering precision, the wider and larger rears to increase grip and get more from the Active M Differential. The aluminium front and five-link rear suspension are identical to that of a 2018 model year M4 Competition Pack.
The only mechanical change to the powertrain is the fitment of a freer flowing exhaust system.
Away from the dynamic upgrades, the M4 CS is also the recipient of a number of weight saving options. The front bonnet has a large air vent positioned ahead of the power dome to draw cooling air through the new front apron, itself featuring a larger air intake. Manufactured from carbonfibre-reinforced plastic the CS’s bonnet is 25 per cent lighter than an M4’s bonnet. There’s also a carbon-fibre front splitter and the roof skin is made from the same material. At the rear there’s a gurney rear spoiler and a diffuser both formed from carbonfibre. Combined with the lighter front seats and naked door cards from the GTS the new CS is 32kg lighter (1580kg) than an M4 fitted with a DCT gearbox.
Engine, performance and 0-100km/h time
Sitting between the Competition Pack and last year’s extreme GTS and DTM editions the CS has also had a laptop plugged into its engine’s ECU, resulting in an additional 7kW (raising power to 338kW produced at 6250rpm) and a peak torque figure of 600Nm available from 4000-5380rpm, a 50Nm increase.
Only the seven-speed M DCT dual clutch gearbox is offered with the CS due to the need to chase numbers, which are quoted at 3.9-seconds to 100km/h (against a regular M4 at 4.2-seconds), a 280km/h maximum and a 7min 38sec Nurburgring lap time.
What’s it like to drive?
The changes BMW has made to the 18-model year M4 Competition Pack are impressive enough. Gone is that layer of disconnect the original car possessed and struggled to provide the confidence required to dig deep into the M4’s reserves and enjoy its obvious talents. There was always a frustration that the M4 had much to give but BMW had made it frustrating to access it. The Competition Pack address these issues, the new CS improves on this further still.
There’s a new found level of focus and precision to the CS. Within only a few miles of committed driving it becomes clear that van Meel and his team has poured over every detail of the M4’s DNA and improved upon it.
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Take how the car reacts to your steering inputs and turns in. Where previously there was an uncomfortable dead spot where it seemed to take a moment too long for the front tyres to react, the CS addresses this with a clarity and level of precision that creates instant confidence. The gripper compound of the Cup 2 tyres are an obvious factor but the steering and set-up changes provide greater confidence to commit on turn in and a much clearer sense as to how the front tyres are working.
Once hooked into a corner the CS feels so much more stable and better balanced, too, the chassis allowing you in to position it so much more cleanly at the apex and ultimately get on the power and work on your exit speed. Not always something that’s been possible in an M4.
In the past deploying the M4’s turbocharged shove was always a bit of a hit and miss affair. Too generous with your right foot and either the traction control went into hyperdrive, or if switched off the rear tyres could easily be vaporised. It was as frustrating on the road as it was impressive for the cameras on the track. In the CS, there’s none of this. Okay, you can play the hooligan if you wish, but it’s so much more rewarding and satisfying to be able to open the throttle earlier in the corner and drive through the exit, feeling the diff hooking up and the chassis working the load with new found precision.
Being able to drive the CS back-to-back with the latest M4 Competition Pack on the former’s launch highlighted that a 7kW gain counts for nothing. However, that punchy torque increase provides the CS with a stronger top end to enjoy.
There are a couple of downsides, however. The seven-speed M DCT is beginning to feel old and a bit slow compared to its rivals and with the transfer to an eight-speed auto for the forthcoming M5 we expect the next M3/4 to go the same way. It’s a shame, because when hooked up and on it the M DCT is a good to use, but away from foot to the floor driving it can be frustrating.
It’s a similar situation with the brakes. The CS comes as standard with cast discs with four-piston calipers at the front, two at the rear and put simply they are not a match for the car’s performance. The biggest criticism is it takes very few committed stops for the pedal travel to lengthen, and while retardation doesn’t suffer at a similar rate it removes the precision required to get the CS slowed and turned in. Ceramics would seem the obvious option to go for.
Price and rivals
It’s likely that the M4 CS will sit halfway between the $154,900 Competition and the $295,000 GTS, so call it $200-220K. It’s certainly a useful step up on the Competition and a useful chunk cheaper than the GTS, but the M4 range now starts at $139,900 for the Pure model, and that might just be the CS’s biggest competition.