The last we heard of the Black Series AMGs from Mercedes-Benz was with the SLS AMG. After the AMG GT replaced it, no other Black Series Mercedes was released, even for other models. However, it could soon return as our spies have spotted a road-going AMG GT4 undergoing tests.
From afar, it can pass off as a standard AMG GT R. In fact it still adorns the factory front bumper and rear wing of the GT R. However, the standard center exit exhaust has been blocked off, with them exiting individually on each side of the rear diffuser. The way the new exhaust exits hints that this is an AMG GT4 built for street use.
Apart from the exhaust, other changes to its exterior include a polycarbonate rear window in order to save weight. To match the exterior changes, Mercedes-AMG has likely deleted some interior comfort parts as well to further keep the weight down.
Power wise, it is still uncertain whether the AMG GT R's factory 4.0-liter bi-turbo V8 engine, also found on the GT4, will be retained in this variant. It is possible that the German automaker could increase power by a few PS to match the changes to the exterior.
As for the name, our spies mention that GT4 is highly unlikely as Mercedes-AMG is currently working on a sedan variant of the AMG GT, likely to be called the GT4. Instead, it is possible that this test vehicle could be the Black Series variant of AMG models. Like previous Black Series models, expect it to have revised aero pack to differentiate it from a standard AMG GT R once a production model has been revealed.