2018 BMW Z4 M40i Prototype Sounds Angry Lapping the Nurburgring

A prototype of the open-top sportscar has recently been spied while doing its thing on the Nurburgring, with the twin-scroll straight-six mill under the hood sounding angry.

We're talking about the automaker's B58 3.0-liter motor, which means that this Z4 packs at least 335 hp and 369 lb-ft of twist. The unit will be mated to an eight-speed automatic tranny and, judging by the action in the Green Hell footage below, the gearbox can deliver instant shifts. Heel-and-toe fans shouldn't fret, though, since a six-speed manual will also be offered.

The launch engine lineup of the 2019 BMW Z4 will also include a pair of turbo-fours, in the form of the sDrive20i and sDrive30i, but the rumor mill simply won't let us end the powertrain story here.

That's because forum chat mentions two other models, namely a hybrid and an all-out M version that would make the M Performance model spied here seem mild.

Whatever you do, don't let the appearance of the 2019 BMW Z4 prototype seen here trick you into believing that the production model will be anything less than gorgeous.

To lure roadster customer in, BMW is ready to maintain most of the Z4 Concept's bewildering looks - you can check out the charm of the one-off in the images below.

BMW showrooms will never welcome a coupe incarnation of the new Z4, since the fifth-generation Toyota Supra will play the role of a fixed-roof model in the sportscar collaboration involving the two brands.

Nevertheless, this hasn't stopped the Internet from coming up with a rendering of a Z4 Coupe, albeit one that skips the double bubble roof hints delivered by the Supra prototypes we've spied so far.