Confused? Us too. Just as we were starting to come around to BMW's new naming convention, where coupes are even numbers and saloons odd numbers, the company previews the slope-roofed Gran Coupe ahead of its debut at the Geneva motor show.
You'll be relieved to learn that this is the third and final member of the 4 Series range, and despite the extra entrances, BMW promises it'll still earn its even number with dynamic loveliness. In terms of scale, it's exactly the same as the two-door coupe – 4,638mm (183 inches) long, 1,825mm wide and a wheelbase of 2,810mm. Only thing is the roof: it's 12mm taller and 112mm longer.
BMW doesn't quote the four-door's weight, but claims that it's "marginally heavier" than the coupe version. Nevertheless, it's taken it upon itself to adjust the GC's suspension and damping. It also gets special strut reinforcement that connects the suspension domes and the bulkhead, which stiffens up the front end and helps steering response.
Engine wise, you'll be able to choose from five power plants initially, which include the same mix of turbocharged petrols and diesels you'll find in a 4 Series. Its opening salvo is the 121g/km, 143bhp 418d diesel, followed by the 280lb ft 420d. The petrol selection is made up of the 184bhp 420i, 245bhp 2-litre 428i, and the range-topping 3-litre turbocharged six-pot, which belts out 306bhp. The latter will cost you £34,795, going down to £29,420 for the 420i.
The company says that two more power plants will join the fray later in 2014, and we're hoping one will be an M4... But if BMW builds it – which, let's face it, it probably will – will that make the M3 saloon completely pointless?
A version of this story originally appeared on TopGear.com.