While the Coupé and Convertible replace models that have traditionally been part of the 3 Series range, BMW would rather we think of the 4 Series line-up as a new and more prestigious breed than the Three.
This upward mobility is in no small part a response to the success of Audi’s A5 range and, indeed, the 4 Series Gran Coupé – with its five-door, five-seat layout finessed into a coupé-like silhouette – aims to swipe market share from the similarly configured A5 Sportback.
The Audi is a shade longer and wider than the BMW, but they are dimensionally closely matched. They share an identical wheelbase and boot capacity of 2810mm and 480 litres – which are also vital statistics of the five-star 3 Series saloon. So while the 4 Series Gran Coupé aims to compete with Audi for premium-ness and better it for dynamics, it might also upsell potential 3 Series buyers.
A 4 Series Gran Coupé SE costs around three grand more than a 3 Series saloon SE, but the Four’s kit levels are significantly more generous, with four trim levels to choose from - SE, Sport, Luxury and M Sport. Opt for the entry-level model and you will find it fitted with dual-zone climate control, cruise control, leather upholstery, front and rear parking sensors, front heated seats and xenon headlights. There is also BMW's iDrive system with a 6.5in display, sat nav, DAB radio, and Bluetooth connectivity. Upgrade to the Sport model and you will find sports front seats, black gloss detailing and bigger alloys thrown in, while the Luxury-trimmed 4 Series adorn the car in more chrome touches and BMW's Professional media system.
The range-topping M Sport trim gets sporty bodykit, interior detailings, suspension and alloy wheels.
With the exception of its standard-fit electrically powered tailgate, the Gran Coupé’s spec matches the Coupé’s, and the two are priced identically – good value when you consider the added practicality of three extra doors and one extra seat (though Audi actually charges less for the A5 in Sportback configuration than it does for the coupé).
Externally, the Gran Coupé retains much of the Coupé’s presence and grace, though it’s a little more cab-heavy. They are identical from nose to A-pillar and have the same length, width and wheelbase, but the Gran Coupé’s roofline is 23mm higher 112mm longer to add room to the rear cabin and boot. Few would argue that the resulting shape isn’t much more handsome than the slightly awkward-looking 3 Series saloon.
The interior shows less progress – the dash layout and switchgear are largely from the 3 Series – and if you choose black hide the cabin is quite gloomy. A few surfaces – door handle surrounds, rear door toppers, rear cup-holders and front seatbacks – are moulded in disappointingly hard plastic, and the handbrake lever feels cheap, but materials are generally good, and driver ergonomics are convincing.
Rear-seat ingress is inhibited by the wheel arches – you have to climb in and then fall back into position – but in the outer two seats, legroom is ample and headroom is acceptable, though outermost shoulders are pushed forwards by the curve of the seatbacks, angling occupants towards the centre console. A perched fifth passenger struggles for head and shoulder room.
The boot has a high lip but is wide and uniformly shaped. Remove the two-part parcel shelf, flip the splitting rear seatbacks forward and you won’t get a fully flat load space, but you will get 1300 litres of maximum capacity – which is only 200 litres shy of a 3 Series Touring.
As for powerplants for the Gran Coupé, there are three petrols and four diesels, all turbocharged. A 2.0-litre four-pot petrol offers 181bhp (in the 420i) or 248bhp (430i), while a 3.0-litre straight six produces 321bhp in the 440i. Most diesels use a 2.0-litre four-pot. It makes 141bhp in the 418d, which is good for 61.4mpg combined and 121g/km of CO2 to court the business user, and 181bhp in the 420d and four-wheel-drive 420d xDrive. All can be had with a six-speed manual gearbox or a £1550 eight-speed auto that slightly improves economy.
While propping up the oil-burner range is a 3.0-litre six-cylinder unit available in two guises - the 252bhp 430d and the 308bhp 435d xDrive. The 420i and the 430d are both available with BMW's automatic four-wheel drive system as well.
We’ve driven the 430i with BMW's eight-speed automatic gearbox, and it’s a drivetrain combination that reflects the Gran Coupé’s character nicely in that it’s refined, easy-going and effective, but not especially exciting. The engine pulls well from 2500rpm and delivers rapid, linear progress following some brief turbo lag. Remarkably, you can barely hear it working below 4000rpm; it gets louder between there and the 6600rpm rev limiter, but it’s more hubbub than harmony. The gearbox works beautifully, though, gently smudging shifts with the Drive Performance Control (DPC) system set to Comfort and zipping through them in Sport.
The 420d is expected to be the biggest seller, and we sampled it in manual xDrive form. This engine shines in the 320d saloon, slinging the car forwards in elastic leaps between gearshifts like a ping pong ball bouncing down a Tarmac path, but add 90kg for the Gran Coupé’s body style and another 75kg for the four-wheel-drive system and it starts to toil at higher speeds. This makes the engine’s chuntering at idle and noisy top end harder to forgive, though it’s still nicely hushed when cruising. The gearshift action is light but precise, while the brakes are sharp but want for pedal feel. The £1500 xDrive option brings launch control-esque getaways and grips securely through quick corners.
The test cars we drove all featured the adaptive damping option, which showed good pliancy allied to tidy body control with the DPC in Sport mode, while Comfort mode allowed settled cruising. Only sharp ridges upset the chassis in town. We’d expect the standard-fit passive dampers to err on the side of comfort, but there is also a lowered M Sport setup.
Our cars also had the Variable Sport Steering option, intended to add agility by quickening responsiveness with lock. Even with it, turn-in is not as sharp as we’d like (despite the additional stiffening applied to the Gran Coupé’s nose) and it actually exhibits a sticky, dead area around the middle that can make the tiller feel a bit neurotic on twisty roads. A stint in a 4 Series Coupé with standard steering revealed a far more natural-feeling, linear helm; a similar setup in the Gran Coupé would be transformative.
The Gran Coupé starts at £30,260 for the 420i SE, which is only £200 more than the cheapest A5 Sportback, which is largely down to the Audi matching the BMW on the equipment front. Pitch the similarly powerful A5 2.0 TDI Quattro SE against the 420d xDrive SE and the BMW costs £200 more, without boasting anymore kit. Both are stylish – though the Audi’s interior is smarter – Munich beats Ingolstadt for dynamics here (allowing for standard steering in the BMW), and would be our choice.
Whether the 4 Series Gran Coupé merits the jump from 3 Series saloon ownership is more debatable. A style and luxury-based decision would fall in favour of the 4 Series, but for unembellished dynamic prowess, the cheaper saloon remains our favourite.