BMW 4 Series Coupe: lighter, faster two-door revealed

Officially revealed, the BMW 4 Series Coupe is longer, wider, lower, up to 45kg lighter and 60 per cent stiffer than its 3 Series Coupe predecessor.

BMW reinforces the reasons for the name change, saying that the new 4 Series Coupe “emphasises not only its stand-alone design, but equally an even greater technical differentiation from its BMW 3 Series cousins”.

Compared with the current 3 Series sedan, the BMW 4 Series Coupe sits a full 67mm lower, and a roll centre reduced by 19mm is the lowest of any current BMW. The 4 Series Coupe is also 14mm longer and wider, with wider front and rear tracks â€" extending by 14mm and 22mm respectively.

BMW calls the 4 Series Coupe design “extremely width-accentuating”. The rear wheelarches are now the widest point of the car, the twin-split kidney grille is larger than before, and the front air dam is positioned lower on the front bumper and has a wider reach across it.

Nestled on the far sides of each air intake are aerodynamically motivated “Air Curtains” that improve air flow around the front wheels, while at the rear of the front wheelarch “Air Breathers” then deflect air out of the arch to reduce resistance. Each are claimed to help reduce fuel consumption. The 4 Series Coupe has an aerodynamic rating of 0.28Cd.

Inside, the BMW 4 Series closely mirrors its 3 Series sedan cousin, with the exception of wider front doors and a redesigned iDrive dial that is now a touch controller. Frameless doors and an automatic seatbelt feeder are 3 Series coupe trademarks that carry over. The 4 Series Coupe also debuts Driving Assistant Plus, which warns the driver of a potential collision with a pedestrian.

A 40:20:40 split folding rear backrest is an option, but a centre ski port is standard.

As with the 3 Series sedan, the 4 Series Coupe is available with three interior design packages called ‘lines’ â€" Modern, Luxury and Sport. An M Sport package is also available, with M Sport suspension and larger 19-inch wheels. Electro-mechanical power steering is standard, with a variable-ratio Sport steering optional along with adaptive dampers.

Three engines are available at launch, all borrowed from the 3 Series Coupe, and each available with a six-speed manual transmission or an eight-speed automatic.

All get stop-start technology, while the auto debuts a ‘coasting’ mode to help reduce fuel consumption, which decouples the engine from the transmission when cruising off the accelerator between 50 and 160km/h.

The 420d Coupe uses a 2.0-litre turbo-diesel four cylinder pproducing 135kW of power at 4000rpm, and 380Nm of torque between 1750-2750rpm. Claimed consumption is 4.7L/100km combined, and the engine pushes the 1450kg two-door to 100km/h in 7.5 seconds.

Middle-grade 428i Coupe gets a 2.0-litre turbo petrol four cylinder with 180kW at 5000-6000rpm and 350Nm between 1250-4800rpm. A 5.9 second 0-100km/h sprint and 6.3L/100km (auto) or 6.6L/100km (manual) fuel usage makes it quicker and more frugal than the 328i sedan.

Flagship for now, the 435i Coupe utilises a 3.0-litre turbo petrol six-cylinder that makes 225kW at 5800-6000rpm and 400Nm from 1200-5000rpm. While the 0-100km/h sprint for the rear-drive version takes 5.4 seconds, the not-for-Australia all-wheel-drive model reduces that time to just 4.9 seconds â€" as quick as the outgoing V8-engined BMW M3. The 1510kg rear-drive 435i drinks 7.3L/100km as an automatic, or 7.9L/100km with a manual transmission.

All 4 Series Coupe models are 60 per cent stiffer than the previous 3 Series Coupe, despite being up to 45kg lighter.

Although the chassis basics mirror the 3 Series sedan, according to BMW the 4 Series, in addition to its lower centre of gravity, has had “its springs and damping, axle kinematics and elastokinematics …  tailored precisely to the hugely engaging character of the new Coupe.”

The BMW 4 Series will make its official public debut at the Frankfurt motor show in September, before going on sale here early 2014. A BMW M4 Coupe will follow later next year to usurp the 435i Coupe’s position as the sports range topper…

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