Long the runt of the litter, mercilessly teased by its 6-Series brother about not having its own nomenclature, today the 3-Series Coupe becomes a man. Internet, welcome the new 4-Series Coupe.

What’s that you cry, no more 3-Series Coupe? Yes. That’ll have repercussions for something much bigger, but we’ll get to that in a second. First, this new 4er is BMW’s attempt to further differentiate the two-door from the classic 3er saloon and enshrine the Schporty characteristics it’s known for.

As such, the new 4-Series Coupe is 26mm longer (with a 50mm longer wheelbase), 10mm lower (with a 16mm lower roofline) and 43mm wider than its 3-Series predecessor. In fact, the front track swells by 45mm, the rear by 80mm, and the rear arches on the Four mark the car’s broadest point. That’s some intent, right there.

See more pics of the new BMW 4-Series Coupe

The looks all but mirror the concept we saw at Detroit, barring the new front apron design incorporating a large air intake and ‘air curtains’. From there, the design sweeps back over the bonnet, with a ‘Hofmeister kink’ along the trailing edges of the C-pillar, double swage lines under the windows, those lovely flared rear arches (it’s rear-wheel-drive, dontchaknow) and the squat rear. Very aggressive, and also a little like a giant man has sat on the roof of the outgoing 3-Series Coupe and squashed it a bit.

The squashed 3er look is actually functional, in a sense, because this car has a lower centre of gravity than its predecessor, which is Good News for the Driving Gloves brigade. The weight distribution is, as ever, 50:50, and it sits on the latest 3-Series saloon chassis, albeit with bespoke springs, damping, axle kinematics and elastokinematics. There are aluminium torque struts, wishbones and swivel bearings up front to reduce unsprung mass, with a classic five-link rear axle setup. Bonzer.

Elsewhere, there’s electric power steering, brakes with aluminium calipers (on the front), lightweight construction, functional aero in the front apron and front arches to reduce drag and four chassis setups (Eco, Comfort, Sport and Sport+), each corresponding to an increase in the level of hairiness the 4er’s throttle, gearbox and steering will tolerate: Eco is a bald coot, Sport+ being a hirsute loon.

See more pics of the new BMW 4-Series Coupe

On launch, BMW will offer just three engines: the turbocharged 3.0-litre six cylinder in the 435i (0-62mph in 5.4s), a turbocharged 2.0-litre four-pot in the 428i (0-62mph in 5.9s) and a 2.0-litre diesel in the 420d (0-62mph in 75s, 60.1mpg). Later, you’ll get the 420i petrol (184bhp), the 430d (258bhp) and finally, the 435d (313bhp and a whopping 465lb ft of torque). All are fitted with a six-speed manual as standard, with the option of an eight-speed auto.

Inside, much is carried over from the classic 3-Series saloon cabin, although there’s also a high-res head-up display, a ‘Driving Assistant’ that scans the road ahead, lane change and departure warning systems, parking assistants, and monitors that analyse your driving behaviour. Bluetooth earpieces at the ready! Actually, scratch that, just use the infotainment setup (which now includes Facebook and Twitter functionality).

Have a click through the pics, and let us know what you think of the new BMW 4-Series Coupe. No word on prices, but the outgoing 3-Series Coupe starts from just over £27k. Be in no doubt that this will drive like a proper BMW, but - as per that repercussion we alluded to earlier - this new nomenclature also means no more BMW M3 Coupe. Now we’ll have the M4. An M4 is also the name of a ruddy assault rifle. A telling move, or coincidence? Only time will tell…