The 2020 BMW 8 Series Gran Coupe. European model shown. Source: BMW

BMW has a habit of stretching definitions, as it did when it introduced a stretched version of the old 6-Series coupe, adding a pair of extra doors and dubbing it a "Gran Coupe." Since then, it has expanded the array of four-door coupes that have fleshed out its line-up. The new 2020 BMW 8-Series Gran Coupe is BMW's latest offering. For those who want more power, however, the new Gran Coupe comes with a brutish, 523-horsepower twin-turbo V-8. Based on the two-door model introduced just a year ago, the new model offers more space and easier entry, as well as the first inline-six engine option available for the 8-Series line. The sporty M850i version will also become one of the automaker's most expensive models ever when it reaches showrooms in September, pushing into six-figure territory when all the option boxes are checked.

Starting price of $85,895

When it reaches U.S. showrooms, expect a starting price of $85,895 for the 840i and $88,705 for the 840i xDrive. The M850i will start at $109,895. BMW is by no means the only luxury automaker that has tried to blur the lines between sedans and coupes. If anything, Mercedes-Benz was a pioneer with the original, CLS model launched in 2004. Mercedes has since added several other models following this design theme, including the smaller CLA. Audi's A7 is another popular competitor, with Porsche offering its Panamera model and Aston Martin weighing in with the Rapide. But none of the competitors offers as broad a range as BMW does with its various Gran Coupe options. The Tesla Model S, which more precisely targets the BMW 7-Series, has been drawing from potential 8-Series buyers, auto industry analysts say. The debut of BMW's Gran Coupe comes almost exactly a year after BMW revealed the two-door version of the 8-Series, reviving a nameplate it abandoned nearly two decades ago and providing a more sporty alternative to the familiar 7-Series sedan flagship.

Coupes lose ground

But, in today's SUV-centric market, coupes have lost even more ground than sedans. The Gran Coupe is expected to solidly outsell the two-door 8-Series going forward as has been the case with earlier Gran Coupe offerings based on the 4-Series and 6-Series lines.

The 2020 BMW 8 Series Gran Coupe. European model shown. Source: BMW

What's clear is that BMW's passenger car line-up, in general, has been struggling of late. While its crossover models, such as the X5, were up 29.0% for the first five months of the year, its sedans, coupes and sports cars were down 15.1%. The 4-Series coupes, including the Gran Coupe, lost 19.4%. Though the 8-Series was never expected to generate massive volume, it only recorded 1,197 sales in the U.S. through the end of May, less than a third the 3,931 7-Series models BMW sold. The automaker is clearly hoping that the addition of the four-door version will help move the needle. That said, BMW designers worked hard to maintain the coupe-like lines of the earlier model, retaining the long nose and sweeping roofline, even though the Gran Coupe features a more upright windshield to allow for a taller roof.

A bigger cabin

It is bigger in most key dimensions, adding 7.9 inches to the two-door's wheelbase, for one thing, and 9.0 inches to overall length. The Gran Coupe also gains 1.2 inches in width and stands 2.2 inches taller, those number translating into a cabin roomy enough to allow adults to sit in the rear without bumping elbows or banging heads whenever the car hits a pothole.

The 2020 BMW 8 Series Gran Coupe. European model shown. Source: BMW

Both versions will come with a panoramic moonroof as standard fare, though the M850i will also offer an optional carbon-fiber roof to reduce overall weight and lower the Gran Coupe's center of gravity. The body itself uses a mix of materials to hold down mass, including aluminum doors and hood and a dent-plastic resistant trunk lid. As one might expect of the BMW flagship, even a base model is lavishly equipped, with standard leather seating and trim, though buyers can opt up to a two-tone leather package, as well. Unlike the two-door model, the Gran Coupe features a wide center console running the length of the cabin to divide it into four seating sections. The rear seats can be folded in a 40/20/40 configuration to open up more cargo space. There are some significant technical features, too, including LED headlamps with Laserlight that help extend a driver's view significantly at night. The rear console features new USB-C ports and the driver has handy access to the latest version of the BMW iDrive infotainment system.

0 to 60 in 3.7 seconds

While BMW offers the 8-Series coupe with a variety of different powertrain options around the world, it limited the U.S. two-door model to the 523-horse power twin-turbo 4.4-liter V-8 found in the M850i trim. That version was able to launch from 0 to 60 in under 3.5 seconds. The heavier Gran Coupe, BMW estimates, will need about 3.7 seconds to get there. Going forward, the Bavarian automaker will add the rear-wheel-drive 840i and 840i xDrive Gran Coupe which will bring to the U.S. a 3.3-liter inline-six making 335 horsepower and 368 pound-feet of torque. It estimates a 0 to 60 launch time of 4.6 seconds for the xDrive model, and a top speed of 155 mph when driving on performance tires. Both engines will be paired with a quick-shifting eight-speed automatic with steering wheel-mounted paddle shifters. The Gran Coupe gets a double-wishbone front suspension and a five-link rear. An active steering system is meant to increase the car's agility, especially during high-speed cornering.