BMW Takes Wraps Off Most Potent Model in M4 Lineup

BMW’s M performance-car division reveals the new 454-hp M4 CS, heralding a new line of limited-edition Club Sport models positioned above the existing range of standard M models but below the ultra-low-volume, stripped-out GTS specials typically launched toward the end of the life of selected M models.

Unveiled by BMW M division Chairman Frank van Meel at the Shanghai auto show, the latest member of the M4 lineup resurrects the CS nomenclature first used by the German automaker on the 2000CS in 1965 but more prominently applied to the 3000CS launched in 1971.

Planned for North American delivery in early 2018, the most powerful M4 model yet holds true to BMW’s earlier club sport traditions, boasting a more powerful engine than even the competition-package-equipped version of the standard M4 already on sale in the US.

Further changes brought to the latest member of the M-car lineup include downforce-inducing aerodynamic tweaks, lightweight carbon-fiber panels and wing elements, various suspension developments, more powerful brakes, larger wheels and tires and a pared-down interior. All of these features, van Meel says, have been honed in a testing and development program carried out mainly at the Nurburging in Germany in a bid to improve the new 2-door coupe’s performance and dynamic ability, both on the road and at the racetrack.

At the heart of the new M4 CS is the most powerful version of BMW M division’s twin-turbocharged 3.0L inline 6-cyl. gasoline engine yet. Fitted with a more free-flowing exhaust and other as-yet-unspecified modifications, it develops 454 hp and 442 lb.-ft (600 Nm) of torque, trumping  the standard M4’s powerplant by 29 hp and 37 lb.-ft. (50 Nm) and the competition package engine tuning available on the recently facelifted M4 by 10 hp and a similar 37 lb.-ft.

The increased reserves are channeled through a revised version of the standard M4’s optional 7-speed dual-clutch gearbox and electronically operated locking differential to the rear wheels. Oddly, given the new BMW’s competition slant, no manual-gearbox option is offered.

The upgraded engine is allied to a range of weight-saving measures, including a roof, front splitter, small gurney spoiler atop the trunklid, diffuser element at the rear all made of carbon-fiber-reinforced plastic.  New lightweight door trims and door pull loops are inside. Together, the M4 CS hits the scales at 3,483 lbs. (1,580 kg), 71 lbs. (32 kg) below the standard M4 equipped with the optional 7-speed dual-clutch gearbox and 22 lbs. (10 kg) below the M4 Competition Package.

This provides the new BMW with a weight-to-power ratio of 7.7 lbs. (3.5 kg) per bhp. By comparison, the 3,505-lbs. (1,577-kg) competition-package-equipped M4 has a weight-to-power ratio of 7.9 lbs. (3.6 kg) per hp.

Although van Meel suggests development was focused more on overall dynamic improvement than pure straight-line speed, the M4 CS outperforms the M4 Competition Package off the line with a claimed 0-62 mph (100 kg) time of 3.9 seconds versus 4.2 seconds. Top speed is a limited 174 mph (278 km/h) also surpasses by 19 mph (30 mph) the fastest of today’s M4 models.

The increased performance comes without any detriment to consumption, as the M4 CS claims combined consumption of 28.0 mpg (8.4 L/100 km).

To ensure sufficient downforce at the increased top speed, BMW M has fitted the new M4 with a more prominent front-splitter element and larger gurney lip spoiler on the trailing edge of the trunk than the standard M4. Further visual upgrades include 3.1-in. (80-mm) chromed tailpipes from the M4 Competition Package.

Chassis upgrades include a revised suspension with stiffer springs and dampers as well as larger roll bars and standard 19-in. front and 20-in. rear DTM-style wheels.

The new M4 comes equipped with the same 4-piston front and 2-piston blue-colored calipers and steel brake discs as the M4 Competition Package, although buyers can opt for 6-piston front and 4-piston calipers painted gold in combination with carbon ceramic brake discs.

Inside, the new M car receives Alcantara trim on the steering wheel and elsewhere. The M4 CS comes in colors including San Marino Blue metallic, Lime Rock Grey metallic, Alpine White, Sapphire Black metallic and Frozen Dark Blue II.

The launch of the M4 CS has raised speculation surrounding BMW M’s plans for a similar conceived version of the M2, which insiders hint could reach BMW dealerships by early 2019.