BMW AG made the executive decision to separate its sedan line from its coupe lines by means of numeric badge differentiations to theoretically help simplify the company’s product ranges. It’s popular 3-Series sedans fall under the number 3, while the coupe versions have been rebadged as the 4-Series. The 5 Series are a line of sedans, and the 6-Series name is again dedicated to a coupe. Sounds pretty simple, right?

It would be, but it appears that BMW isn’t too concerned with the purity of each numeric nameplate, evidenced by Sunday’s introduction of the 4 Series Gran Coupe, a four-door model of BMW’s 4-Series two-door coupe. On a size basis, the 4-Series Gran Coupe is just slightly larger than the 3-Series sedan; its about half an inch longer, but about about an inch an a half shorter.

Cargo space is equal to the 3-Series, tying at about 17 cubic feet, but Autoblog points out that because the Gran Coupe is actually more of a hatchback design — not a true sedan as the 3-Series is — the rear cargo hold should theoretically be easier to access.

The Gran Coupe is clearly aimed at offering a more sporty four-door sedan-type car, as it offers the aforementioned lower profile, a sleeker raked rear window and trunk lid, the muscular rear fenders, and the lower overall stance that gives the 4-Series a more aggressive persona than its 3-Series sedan cousin.

For power, the Gran Coupe offers nothing unexpected; the engine menu is the same as the one offered for the rest of the 3- and 4-Series families. That consists of BMW’s 2.0 liter turbocharged inline-four with 240 horsepower and 255 pound-feet of torque, and when upgraded to the 435i trim, the four-banger is swapped out for BMW’s silky smooth 3.0 liter turbo-six with 300 horsepower and 300 pound-feet.

So after the big rebadging effort and the clear distinctions between the 2-door and 4-door lines, why blur the lines? Our best guess would be that the Gran Coupes — there’s a 6-Series Gran Coupe as well, which is a four-door model of the 6-Series Coupe — are BMW’s attempt at taking on the likes of the Audi A7 and Mercedes-Benz CLS.

Despite being somewhat redundant next to the 3-Series sedans, the 428i models will reportedly carry a $3,000 premium over the comparable 328i sedans, and the 435i Gran Coupe costs $2,400 more than a 335i sedan, Autoblog notes. BMW’s M Sport package will also be available for the Gran Coupe.

What the Gran Coupe appears to be is a more attractive, sleeker, and more appealing 3-Series sedan with a more accessible trunk, and BMW’s clientele will likely have little problem spending the extra coin for the new model. What effect this will have on sales of the 3-Series — in terms of cannibalization — has yet to be seen, and with the muddling of its badging strategy aside, BMW seems to have built a very serious contender in the luxury hatchback/sedan market as the answer to the question that no one seemed to be asking.