Overall rating:

Some will wonder why BMW now has the 3 Series Gran Turismo and the new 4 Series Gran Coupé in its line-up. The latter is closer in feel to the two-door 4 Series Coupé, though like that car it gives up a little sharpness in the pursuit of better cruising ability and comfort. Can it live up to the marker laid down by the stunning 6 Series Gran Coupé?

Key Facts

Model tested: BMW 428i M Sport Gran Coupé
Pricing: £37,335 on-the-road as tested (Gran Coupé starts at £29,425)
Engine: 2.0-litre four-cylinder turbocharged petrol
Transmission: eight-speed automatic, rear-wheel drive
Body style: four-door coupé
Rivals: Audi A5 Sportback, Lexus IS 300h, Mercedes-Benz C-Class
CO₂ emissions: 147g/km
Combined economy: 44.8mpg
Top speed: 155mph
0-62mph: 6.0 seconds
Power: 245hp from 5,000- to 6,500rpm
Torque: 350Nm from 1,250- to 4,800rpm

In the Metal:

It's hard to believe that the Gran Coupé is built on the same wheelbase as the two-door BMW 4 Series Coupé, and it's no longer or wider. The elongated and raised roof fool your eyes into thinking the car has gotta be longer, not to mention the addition of more doors. Yet the 2,810mm wheelbase is also identical to that of this car's biggest rival, the Audi A5 Sportback. The BMW looks sensational from most angles, though on certain wheels and in some colours the longer roof doesn't sit so well. Nonetheless, we reckon it's a successful transition overall.

Under that new tailgate (automatically opening and closing as standard) the Gran Coupé holds 35 litres more luggage than the two-door car, at a 3 Series Saloon and A5 Sportback equalling 480 litres. The 40:20:40 split rear seat back remains and headroom is improved a tad thanks to the new roofline. It's still not what you'd call capacious, but it's not cramped either. Clearly the front seats take priority and, just like the regular Coupé, the M Sport model comes with a great leather steering wheel, in this case backed by metallic gearchange paddles for the sport automatic transmission. It's a lovely place to be and a great driving position.

Driving it:

Not only does the Gran Coupé take up the same space on the road as its two-door sibling, it weighs only a little more. In 428i M Sport Auto guise it's 60kg more, which is less than the average adult weighs. Hence there are few surprises with how this car drives. Indeed, the options buyers can add, such as the transmission, adaptive damping, larger wheels, etc. have a more marked effect on the personality of the car.

Saying all that, we were a little surprised to find this variant so comfortable. We started out in the default Comfort setting, which was ideal for high-speed motorway work, but once we hit the interesting mountain roads the soft throttle response and extra body roll soon had us toggling the 'Driving Experience Control' switch into Sport mode. As ever in a BMW, this means less steering assistance, sharper throttle response, quicker gearshifts and, as this car had adaptive damping, firmer suspension. The engine becomes more audible in this guise too, though it's a quiet, cultured unit. That's great when cruising, but it lacks soul when you're really pushing on. Few turbocharged four-cylinder engines are any better in truth. Not that there's any complaint with the performance on offer, though the torque curve is so flat that it's deceptively fast.

Arrive at a corner a little too quickly and the Gran Coupé safely scrubs off the excess speed with a minor amount of understeer, though its natural stance is very neutral. In the dry it takes a lot of provocation to unstick the rear tyres, and even then it's more likely that the inside wheel will spin rather than the whole back end slide out of control. That's good for most people, if a little lacking in engagement for driving enthusiasts. Still, the inherent balance in the chassis should make a great basis for versions with more torque.

What you get for your Money:

Bizarrely, BMW is pitching the 4 Series Gran Coupé at exactly the same price as the two-door version - and specifications will be nigh on identical too. The 420i SE Gran Coupé is the cheapest model at £29,425, while diesel power , in the form of the 418d, kicks off at £30,995. Petrol models are called 420i and 428i (both turbocharged 2.0-litre petrol engines) or the range-topping 435i with its turbocharged six-cylinder unit. Clearly the diesels will be more popular, and alongside the 418d and 420d there will be six-cylinder turbodiesel options in the 430d and 435d. BMW will offer xDrive four-wheel drive with most of the engines and trim lines are SE, Sport, Modern, Luxury and M Sport.

Worth Noting

Nobody at the launch would confirm its existence, but we'd be shocked if BMW doesn't roll out an M4 Gran Coupé sometime in 2015. It's a no brainer, especially given how utterly fantastic the regular M4 Coupé is. We quite like the idea of this body shell with a carbon roof and a 431hp twin-turbocharged 3.0-litre six-cylinder engine under the bonnet. Watch this space.

Summary

The arrival of the BMW 4 Series Gran Coupé was inevitable; Audi couldn't be allowed to have things all its own way with the A5 Sportback, now could it? The BMW is a good match for that car and though its specification and reputation suggests otherwise it's at least as good a cruiser and everyday car as the Audi, while being a little more interesting to drive. In its more common guises it'll not excite driving nuts, but it still makes a compelling argument for itself as an alternative to a regular saloon.