BMW has confirmed the 3-Series coupe will become a dedicated model in its own right and receive a new 4-Series coupe name when production gets under way in 2013.
The long-mooted change to BMW's traditional line-up mirrors the step taken in 2003 with the resurrection of the larger 6-Series coupe.
It is considered significant enough to prompt the German carmaker to preview the new two-door model with this striking 4-Series coupe concept car, which is expected to make its public premiere at the upcoming Detroit motor show.
"The 4-Series doesn't just mark the start of a new cycle; it marks the start of a model with its own individual character and a stand-alone design," BMW said. "It stands for greater sportiness, added exclusivity and even clearer differentiation from the 3-Series."
While described as a design study, the 4-Series coupe concept to be wheeled out in Detroit is understood to closely preview the look of the upcoming production version of BMW's new two-door model. Only detail changes are expected, including less flamboyantly styled bumpers and the incorporation of more conventional exterior mirrors, door handles and tail pipes.
At 4641mm in length, 1826mm in width and 1362mm in height, the new two-door is 31mm longer, 44mm wider and 16mm lower than the outgoing 3-Series coupe. It also rides on a larger chassis than the model it replaces, with the wheelbase extended by 50mm to 2810mm. The front and rear tracks have been increased by 45mm and 80mm to 1545mm and 1593mm respectively – figures BMW hints leads to improved interior packaging and greater levels of accommodation.
Despite aiming for a more individual look, BMW's designers have clearly taken inspiration from the latest 3-Series in creating the look of the new 4-Series. The two cars share similar front designs, side swage line and window graphic treatment. But with more acute screen angles, greater curvature to its roofline and a shorter boot line, the new two-door boasts a distinctly more sporting profile than its four-door sibling. The surfacing treatment also differs with greater contouring within the bonnet, added structure within the flanks and a more defined shoulder.
BMW's design team has also provided the new car with a chrome decoration within the front wings. Insiders reveal the production car will feature some sort of adornment, although just how close it is to that of the concept car remains to be seen.
Developed under the internal codename F32, the 4-Series coupe is based on the same high-strength steel platform structure and uses the same aluminium-intensive underpinnings as the latest 3-Series sedan. Alongside standard rear-wheel-drive models, BMW also plans to unleash selected four-wheel-drive xDrive versions of the new coupe.
BMW is yet to reveal the engine line-up for its sleek new Audi A5 and Mercedes-Benz C-Class coupe-rivalling 4-Series coupe. A range of up to seven turbocharged four and six-cylinder petrol and diesel units, all mounted longitudinally and featuring a stop/start function and brake energy recuperation as part of BMW's EfficientDynamics program, are expected to create new 418i, 420i, 428i and 435i petrol-powered models and 420d, 425d, 430d and 435d diesel models. Gearboxes will include a six-speed manual or eight-speed automatic depending on the engine sitting up front.
Spearheading the 4-Series coupe line-up will be an eagerly anticipated range-topping M3 replacement planned to be unveiled at next year's Frankfurt motor show. Set to adopt the M4 nomenclature, BMW's new performance coupe will eschew the naturally aspirated 4.0-litre V8 engine used today in favour of a new twin turbocharged 3.0-litre in-line six-cylinder powerplant that is claimed to develop in the region of 335kW.
BMW sources suggest the iconic M3 name will continue to be used, but only on powered up versions of the 3-Series sedan.
The interior of the 4-Series coupe is heavily based on that of the 3-Series sedan. Apart from a liberal covering of leather featured on the concept car, the instrument binnacle, upper dashboard mould, centre console, infotainment monitor and switchgear all appear to have been carried over virtually unchanged.
The move to adopt the 4-Series name follows BMW's earlier decision to resurrect the 6-Series in 2003 after a 14-year hiatus. Now in its third generation, it supports three different models: coupe, convertible and GranCoupe.
In a move mirroring that of its larger sibling, the new 4-Series is planned to grow to include the coupe revealed here in concept car guise for the first time together with a convertible and GranCoupe – the latter two of which are planned to be introduced to the Australian market in 2014.
-Fairfax News Australia
Should the speed limit be raised to 110kmh on some roads?Related story: 110kmh limit moves closer