We admire its muscle-car looks, performance potential and rear-drive chassis. Being a product of M GmbH also infuses it with a desirability that rivals are still some way from achieving. Yet it’s been a struggle to wholly fall for the M4. Its biturbocharged 3-litre straight-six has the punch to fire it down a road and around a track with a force that would make Anthony Joshua swerve. But this has also been its downfall. So thuggish has been the delivery to the rear tyres that not only do they give up the fight for traction earlier than you are expecting, but so too does the rear suspension, throwing in the towel at the first sign of any loading through its springs and dampers. It makes for an infuriating experience, because on its day, on the right road and in the right conditions – a bone-dry, smooth surface – the M4 is your best mate. But few of us live at the Ascari race resort, so it’s often a mate you leave the pub early to avoid. How, then, is BMW’s new M4CS going to cope with a 30hp increase to 460hp and an additional 50Nm, bringing the total to 600Nm?
The first part of the answer is the M4 Competition Package of 2016, which brought a lower ride height and stiffer springs, dampers and anti-roll bars. It greatly improved the base M is behaviour, even with a power increase to 450hp. For MY18 cars, the Comp Pack itself has been improved (the upgrade has been upgraded, essentially), and it acts as a basis for the M4 CS we have here. M division chief Frank van Meel confirms there’s been not a single hardware change to the M4 CS’s chassis over that of the MY18 M4 Competition Package.
Rather, he and his team have been busy with the laptops, reprogramming the M Adaptive suspension to better suit the now standard Michel in Cup 2 tyres. It’s the same situation with the electric power steering and the engine ECU, both of which have been optimised to sharpen the CS. There are a number of further detail changes to the CS. It’s only available with the seven-speed M DCT double-clutch gearbox, and in addition to the carbonfibre roof that’s already standard on the M4, the front splitter, rear diffuse rand bonnet are also carbon, the bonnet being 25 per cent lighter than the regular aluminium panel. The new bonnet also features a sizable vent ahead of the powerdome.
The 19in front and 20in rear wheels are lightweight items with 265/35 rubber at the front and 285/30 at the rear, the former being the focus for much of the damper tuning to improve steering precision. The only big mechanical change is the fitment of a more free-flowing exhaust, and due to the lack of any front speakers, there’s no sound imposer, meaning you hear an M engine playing its natural tune rather than a digitally enhanced one. Other changes inside include lightweight door-cards from the GTS, a pair of manually adjustable lightweight sports seats and a steering wheel and centre-console trimmed in Alcantara.
All in all, there’s a 35kg weight saving, down to 1505kg compared to 1540kg for an M4 with an M DCT gearbox. The CS cracks 100km/h in a claimed 3.9sec (two-tenths quicker than the DCT standard M4) and runs on to 280km/h. And, of course, there’s a Ring lap time of 7 min 38sec. These numbers pale Into the Insignificant when it comes to the road, though, because whatever van Meel and his team have done to the underbelly of the CS, it has transformed the M4 from an unpredictable and ultimately frustrating performance car into one with all the character, ability and entertainment of M-cars of old. It’s how the CS reacts to your steering inputs that hits you first.
Where previous M4s have an uncomfortable dead spot and take a moment for the front tyres to react, the CS’s nose is rich in clarity, speed and precision, delivering instant confidence. The gripper Cup 2 tyres are an obvious factor in this, but the steering and setup changes allow you to commit harder because there’s a clearer sense of how the chassis is working beneath you. Hooked into a corner, the CS feels much more stable and better balanced, the chassis allowing you to position it so much more accurately at the apex, get on the power earlier and work on your exit speed. With previous M4s this 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 it was switched off, the rear tyres would vaporise. The car was as frustrating on the road as it was impressive for the cameras on track. That it also acted up when trying to put the power down in a straight line didn’t help it win friends, either.
In the CS there’s none of this. You can play the hooligan if you wish, but it’s so much more rewarding and satisfying to be able to open the throttle early in the corner and drive through the exit feeling the M-diff hook up and the chassis working the load with newfound precision. Downsides? The DCT gearbox now feels old in comparison to rivals and the brakes come up short, too. The standard cast-iron discs, with four-piston calipers at the front, two at the rear, are not a match for the car’s performance – it takes only a few committed stops for the pedal travel to lengthen, and while retardation doesn’t decline, the precision does. The optional carbon-ceramics help. There’s another Issue. The £89,130 ($157,260) price tag is a £25k ($44,100) premium over a Competition Package, which makes it extremely hard to recommend the CS on price alone, despite it currently being the ultimate M4.