When BMW->ke178 took the decision to segment its 3 Series->ke290 lineup into more body styles, the M3->ke2366 Coupe disappeared and was replaced by the new M4, one of the many novelties that the latest M-powered sports car->ke506 surprised everyone with. Another major surprise was the car's switch to a twin-turbocharged inline-six, which was seen by a lot of purist as a downgrade from the high-revving and naturally-aspirated V-8 found in the previous generation. Set to bring back some of its fans and also gain others, the upcoming 2016 BMW M4 GTS will be the most hardcore variant of the lineup, a direct successor to the track-ready M3 GTS.

While not officially confirmed as of yet, the upcoming GTS version of the BMW M4 is hard at work testing in all types of conditions, with a pre-production prototype having been spied drifting around on the snow in northern Sweden. BMW testers had covered the lower part of the front bumper, but an all-new and rather aggressive front lip is rather evident on the model, as is the small rear wing, the Recaro bucket seats inside and the carbon-ceramic brakes with gold-painted braking pads.

The model is expected to shed quite a lot of weight compared with a standard BMW M4, with the loss mainly being achieved by the removal of the rear seats and even more use of carbon-fiber-reinforced plastics (CFRP). The 3.0-liter, twin-turbocharged inline-six may also get a slight bump in power from the standard 425 horsepower and 406 pound-feet of torque, but most of the GTS performance additives will follow Colin Chapman's philosophy of "simplify, then add lightness." Expect the model to be launched sometime in 2015, with a Geneva Motor Show->ke228 reveal being likely.

Click past the jump to read more about the BMW M4 GTS.

Why it matters

Despite losing quite a lot of weight and improving both performance and fuel economy figures by a large margin compared with its predecessor, the new BMW M4 seems to no longer be the undisputed king in its segment. This opinion comes mainly because a lot of compromises have been made in its creation, with the most evident being a severe lack of driver involvement coming from the electrically-assisted steering and the vacuum cleaner-sound of its twin-turbocharged engine. BMW went as far as augmenting the engine sound via the audio system for the passengers.

With that being said, the upcoming M4 GTS version should be a true successor to the hardcore M3 Coupe models of old, bringing tons of improved track performance and a "racing car for the road" overall feel. Naturally, this is all speculation for the time being, but judging by how much lighter was the M3 GTS compared with the regular model (almost 300 pounds!) makes me feel pretty optimistic about the new one.

Spy shots

2016 BMW M4 GTS - rendering