With the X167 Mercedes-Benz GLS officially out, it’s only a matter of time before the AMG 53 and 63 models roll out. Right here, according to our spy photographers, is a prototype for the latter.

It’s still completely camouflaged, but details like the cross-drilled rotors (front and rear), gigantic 22-inch wheels, and quad trapezoidal exhaust exits all point towards the AMG 63 badge. In any case, the top GLS is likely to share the same M178 4.0 litre biturbo V8 as the upcoming GLE 63, outputting around 600 hp and 850 Nm of torque. The M178 engine can also be found in the current E 63 S, AMG GT and G63.

In the E 63 S, the output enables a 0-100 km/h time of 3.4 seconds, whereas the top speed is electronically limited to 250 km/h. At launch, the GLS 63 could potentially be electrified, along with the automaker’s plans to electrify (with plug-in capabilities) the entire AMG line-up from 2020 onwards.

Ola Kallenius, member of the board of management of Daimler AG responsible for Group Research and Mercedes-Benz Cars Development, recently said the electric-only operating range for its PHEVs is currently up to 50 km on a worldwide harmonised light vehicles (WLTP) test cycle, but added that it will be doubled to 100 km when the next-gen of PHEVs debut.

The AMG PHEVs, on the other hand, will come with a performance-tuned version of the hybrid system, which will sacrifice some operating range. Mercedes’ head of external affairs for emissions, Frank Overmeyer said the battery, application and electric motor will be the same, thus offering around 100 km of range. But on an AMG-badged model, the pure electric range may only be 60 or 70 km.

GALLERY: X167 Mercedes-Benz GLS