BMW has finally released preliminary details of the next-generation 4 Series Coupe, which is known internally as the G22. In an official release, the German carmaker is more than happy to reveal that the model is undergoing the final round of testing, along with a few details about the development process and specifications. While a debut date wasn’t mentioned, reports indicate a June reveal for the sleek and sport coupe.

Getting to the juicy bits first, the 4 Series Coupe will be headlined by the M440i xDrive, which is the range-topping variant in the line-up. BMW says the variant offers 374 PS (369 hp) and 500 Nm of torque from a turbocharged straight-six engine, which sounds more or less identical to the B58 3.0 litre unit found in 3 Series Sedan and Touring sold in Europe, specifically the M340i and M340i xDrive (the United States gets the sedan with 387 PS or 382 hp).

However, the 4 Series is differentiated from the 3er by its 48-volt mild hybrid system that consists of a starter-generator and a second battery. The mild hybrid system is meant to support the engine by providing an 11 PS (11 hp) electric boost to fill in the gap before the turbo really gets to work from 1,500 rpm, or to provide off-throttle coasting.

As for the rest of the setup, the engine channels power to all four wheels via an eight-speed Steptronic Sport automatic transmission and BMW’s obligatory xDrive all-wheel drive system. There’s also an electronically-controlled M Sport differential to help distribute power to the rear wheels properly, along with M Sport brakes and 18-inch M light-alloy wheels with mixed-size tyres.

Other variants that will be offered include the 430i, which uses a B48 2.0 litre turbo-four with 258 PS (255 hp) and 400 Nm (identical to the 330i). It too will come with an eight-speed automatic gearbox, but makes do with a rear-wheel drive layout instead. Autocar UK reports that the line-up will be extended to include the 420i, 430d and 435d as well.

Underneath the sheet metal (and various aluminium panels), the 4 Series rides on the CLAR (Cluster Architecture) platform found in other recent BMWs, giving it a 42 mm longer wheelbase than its predecessor, at 2,852 mm. The company also says the coupe is 57 mm longer than the 3 Series and its lower roofline contributes to a lower centre of gravity by 21 mm.

BMW is adamant that the new 4 Series is not just a rebodied 3 Series with two less doors, and notes that the model’s sport-focused setup comes with a wider track of 23 mm compared to the sedan, while the double-joint spring strut front axle/five-link rear axle suspension gets its own unique settings and elastokinematics properties, including more negative camber up front.

Model-specific bracing elements have also been added around the rear axle to increase stiffness for improved straight-line stability and lateral acceleration. To optimise steering precision and response, the car also gets custom-made tower-to-front end struts and an additional shear panel on the bulkhead.

The 4 Series Coupe will be joined by a convertible (G23) and Gran Coupe (G24) body styles in the future, with the former set to adopt a folding soft top instead of a hard top. The controversial twin kidney grille and sloping roofline are key talking points of the 4er’s styling, although the finer details are masked behind camouflage, as these photos show.

Similarly, most of the interior remains covered up for now, although we now from previous spyshots that it will be very similar to the 3 Series, including the BMW Live Cockpit Professional system that is now common in other BMW models, the design of the steering wheel, and the layout of the centre console controls.