If BMW’s revised line-up of late hadn’t confused you enough, here’s another one to add to the mix: the 4 Series Gran Coupe. Built on the same platform as the 4 Series, which was previously the 3 Series Coupe (are you still with me?), it’s a four-door stretched version, built to compete with the Audi A5 Sportback and the Mercedes-Benz CLA.

That means it targets buyers that want the looks of a coupe, with the practicality of four doors and more space in the boot. BMW openly admits that it will also appeal to 3 Series owners wanting a change, helping to keep them within the brand, rather than going to rivals.

So has BMW continued its winning formula from the standard 4 Series with this niche variant?

Performance

The confusion continues with the engine line-up, but echoes the 4 Series, except for the addition of a 418d iteration, to appeal to company car drivers which will make up the majority of buyers. The 420d diesel will be the most popular, while the 435i petrol is the most powerful of the range. Select models are available with BMW’s xDrive four-wheel-drive, intended to compete with Audi’s Quattro vehicles.

We tested the 420d xDrive in manual, which will keep a third of Gran Coupe buyers happy, says BMW. And while it's never going to set heart alights, the powertrain packs plenty of punch to manage any road scenario. Hitting 0-62mph in 7.7 seconds in six-speed manual and maxing out at 147mph will keep almost all business execs content, while the even more fleet-friendly 418d ups that figure to 9.9 seconds.

The four-wheel-drive system isn’t evident on your average journey, until you really need a lot of grip, and will become most relevant in the icy winter months, which no doubt has a large part to play in the popularity of xDrive in the UK.

We also tested the 428i in eight-speed auto mode, which sits below the top petrol in the range, the 435i. This is when the fun begins, with the benchmark sprint achieved in 6 seconds, with a top speed of 155mph. That’s 0.8 seconds slower than the equivalent 435i auto. Based on our tests in the 420d and the 428i, we’d opt for the automatic transmission, which fluidly changes between gears, and makes the cars a touch quicker too.

BMW has worked hard to keep the appeal of the standard 4 Series Coupe, while adding practicality, and the 0-62mph figures demonstrate this, with only 0.1 or 0.2 seconds added to the equivalent Gran Coupe models, despite the extra weight and space.

Ride and Handling

BMW’s four-cylinder diesel engines aren’t known for their smoothness, and the 420d continues to grumble at start-up, but once it’s up and running, it’s a well-refined car.

The 4 Series is a joy to drive, and pleasingly, the Gran Coupe isn’t far off. Despite the extra doors, it has the same overall width, length and wheelbase, but with a higher, elongated roof, to keep those rear passengers comfortable. That means it handles in a similar way, with light, accurate and responsive steering, and excellent grip around bends and at higher speeds. BMW’s four-cylinder diesel engines aren’t known for their smoothness, and the 420d continues to grumble at start-up, but once it’s up and running, it’s a well-refined car, with decent insulation despite the presence of frameless doors, carried through from the Coupe. Both of our tests cars had optional Adaptive M Sport suspension fitted (£750), but ride has been tempered successfully, and purposefully pushed on a host of speed bumps, the Gran Coupe soaked up the unsteadiness with ease, making this a very comfortable cruiser when it needs to be.

Interior and Equipment

As well as a Gran Coupe derivative, the BMW 4 Series is also available in separate Coupe and Convertible body styles.

The interior appearance and quality is exactly the same as the Coupe, making it a comfortable, appealing and easy-to-use cabin. Meanwhile, the four trim levels also echo the two-door model – SE, Sport, Luxury and M Sport - with good levels of standard equipment including leather interior, heated front seats and xenon headlights. So while it has the same wheelbase as the coupe, there’s a respectable amount of room in the back, with 27mm more headroom in the rear, helped by a 12mm higher roofline. There’s also room for five people, compared to the Coupe’s four. Boot space is also up 35 litres over the coupe, at 480 litres, which matches the 3 Series saloon for luggage load. All Gran Coupes come with an automatic tailgate opening as standard, which BMW was keen to point out isn’t even available as an option on the A5 Sportback. You win some, you lose some…

Cost

The most popular 420d model on the other hand emits 124g in manual mode and 60.1mpg. Adding xDrive takes that up to 129g and 57.6mpg.

The 418d, aimed purely at the corporate market, is the most wallet-friendly, with CO2 emissions as low as 118g and fuel economy of 61.4mpg. The most popular 420d model on the other hand emits 124g in manual mode and 60.1mpg. Adding xDrive takes that up to 129g and 57.6mpg. Price wise, the 4 Series Gran Coupe is comparable to the likes of the Audi A5 Coupe.

Our Verdict

It’s increasingly hard to keep up with BMW’s range, but providing customers know all of the choices out there, this car will only bolster the brand’s sales. By wising up to the business demand for four doors alongside the desire for coupe-like cars, the 4 Series Gran Coupe will steal plenty of thunder from rivals and its very own less stylish 3 Series. Aside to its luxurious nature, it is also incredibly competent on the road and very fun, even though it is a rather large set of wheels.