Mercedes-Benz AMG is working on a new member of its GT Coupe family that’s expected to sit somewhere between the current GT 63 grade and an upcoming plug-in hybrid range-topper that will likely be badged the GT 63 S E Performance.

A prototype has been spotted and the lack of camouflage gear suggests a debut might happen later this year.

The lack of a charging port at the rear and the typical yellow warning stickers for electrified test vehicles point to the prototype skipping a plug-in hybrid powertrain.

The wider front fenders and square shape of the exhaust tips are also the same as those found on GT Coupe models equipped with AMG’s twin-turbocharged 4.0-liter V-8, suggesting that’s the powertrain the new variant is running.

Other elements borrowed from the GT 63 include the fixed rear wing and carbon-ceramic brake rotors. The front fascia, which is the only area camouflaged, is a unique design, though.

Given these clues, a possible name for the new variant is GT 63 S.

In addition, the peak power should lie somewhere between the 577 hp of the GT 63 and the expected 805 hp of the GT 63 S E Performance plug-in hybrid.

The latest GT Coupe was introduced for the 2024 model year, bringing with it a bigger footprint than the car it replaced, plus 2+2 seating. For the 2025 model year, AMG added an entry-level GT 43 grade equipped with a 2.0-liter turbo-4 good for 416 hp. The GT 63 S E Performance plug-in hybrid is also expected to arrive for the 2025 model year.

The new variant, whatever it ends up being called, may only arrive as a 2026 model year, which would mean a market launch sometime next year.

We will likely be treated to even more GT Coupe variants in the future. Using the car’s predecessor is a guide, track-focused GT R and Black Series grades may also be in the pipeline.