BMW has finally revealed its all-new M3 sedan as well as its first M4 coupe, "which capitalize on the strengths of the latest 3-Series sedan and fresh 4-Series coupe as their respective foundations."
The new M3 and M4 mark a return to the in-line-six engine made famous by BMW M, with the turbocharged 3.0-liter mill producing 425hp and 550Nm, propelling both models to 100kph in 4.3 seconds with the six-speed manual transmission and 4.1 seconds with the seven-speed M double-clutch gearbox. Yet despite being more powerful than the V8 unit of its predecessors, the new powerplant is more fuel-efficient and produces fewer emissions by roughly 25%.
On top of the new engine, one of the primary objectives of the M3 sedan and M4 coupe's development was to give it a track-specification cooling system, "which ensures that the optimum temperature balance for the engine, turbochargers and transmission is maintained at all times. To achieve this, BMW M engineers worked closely with BMW Motorsport's professional racing drivers during the development phase, with DTM drivers Bruno Spengler and Timo Glock taking part in the extensive testing and setup work carried out at the Nurburgring's Nordschleife circuit.
Aerodynamics also played a big part in the M3 sedan and M4 coupe's development, with the front apron, smooth underbody and Gurney spoiler at the rear of the M3 sedan--or integrated spoiler lip at the rear of the BMW M4 Coupe--reducing lift by an equal degree at the front and rear axles to produce optimum handling attributes.
Carbon-fiber-reinforced plastic is also widely used in both cars. The M3 sedan and the M4 coupe both make use of a CFRP propeller shaft, with its high rigidity and low weight allowing it to be produced as a single component minus a center bearing. A 1.5kg CFRP strut brace in the engine compartment also offers superior rigidity and enhances the car's steering response. Also, while the material was used in the coupe's predecessor exclusively, the sedan will, for the first time, also sport the same CFRP roof, thereby lowering the car's center of gravity and enhancing its driving dynamics.
"Four generations of the BMW M3 have blended motorsport genes and uncompromised everyday usability within an emotionally rich overall concept," said BMW M GmbH president Friedrich Nitschke. "The BMW M3 sedan and the BMW M4 coupe represent an ongoing commitment to this philosophy. The engine is the heart of every M model, and the new turbocharged six-cylinder unit fitted in the two new cars combines the virtues of a high-revving naturally aspirated unit with the strengths of turbocharger technology. A committed lightweight design concept produces a weight saving of around 80kg over the outgoing M3."
Both the M3 sedan and the M4 coupe will make their debut at the 2014 Detroit Auto Show, with sales beginning in the second half of 2014.