The Mercedes-AMG GT 4-Door Coupe is an executive car introduced in 2018 by Mercedes-AMG as a five-door variant of the AMG GT two-door sports car. The AMG GT 4-Door Coupe uses a front-engine layout with 4MATIC+ fully variable all-wheel-drive, and is available with either a 3.0 L turbo/supercharged inline-six engine or a 4.0 L twin-turbocharged V8 engine. The inline-six engine features a conventional turbocharger as well as a mild hybrid system that Mercedes-Benz calls "EQ Boost", which uses an electrically driven supercharger and a 48 volt electric motor that when combined, produce an extra 21 hp (16 kW) and 184 lb ft (249 Nm) of torque in addition to the petrol engine when it is not powering the electrical system. This system traces its roots back to the Mercedes CLS53. The car utilises the rear anti-roll bar to increase chassis stiffness, as well as active aero, including an electronically adjustable rear spoiler and electronically operated front louvers in the front grille, that can open and close to manage airflow through the radiator from the AMG GTR flagship sports car. The GT 43 is the entry level variant of the AMG GT 4-Door Coupe and features the 3.0L turbo/supercharged inline-six and the 4MATIC+ AWD system. The engine produces 270 kW (362 hp) and 502 Nm (370 lb ft) of torque and can accelerate from 0–100 km/h (0–62 mph) in 4.9 seconds, with a claimed top speed of 270 km/h (168 mph). The GT 53 is the more powerful version of the GT 43. It features the same 3.0L turbo/supercharged inline-six, but with higher outputs. The engine produces 320 kW (429 hp) and 500 Nm (369 lb ft) of torque. The starter-generator and electrically driven supercharger called EQ boost supplements the engine temporarily with 16 kW (21 hp) and 250 Nm (184 lb ft) of torque while under full acceleration. It can accelerate from 0–100 km/h (0–62 mph) in 4.5 seconds, along with attaining a top speed of 285 km/h (177 mph) as tested by the manufacturer. The suspension uses steel springs and adaptive dampers and the clutch is a TCT unit that uses a conventional torque converter. The GT 63 is a high performance, better equipped variant of the GT 4-Door and features the AMG M177 4.0L twin-turbocharged V8 engine, which produces 430 kW (577 hp) and 800 Nm (590 lb ft). It has a claimed 0–62 mph (100 km/h) acceleration time of 3.4 seconds and a top speed of 311 km/h (193 mph) as tested by the manufacturer. The GT 63 also has an optional selectable "Drift Mode" which directs power solely to the rear wheels. The car comes standard with an electronically controlled limited-slip rear differential and rear-wheel steering, and features an MCT gearbox with a wet clutch to handle the extra power. The GT 63 uses AMG's multi-chamber air suspension for a sportier, more adaptive ride and has cylinder deactivation mode for increased efficiency. The GT 63S is the top of the line variant of the GT 4-Door and features the same 4.0L twin-turbocharged V8 engine as in the GT 63, but receives further tuning to produce 470 kW (630 hp) and 900 Nm (664 lb ft) of torque. The GT 63S will reportedly accelerate from 0–100 km/h (0–62 mph) in 3.2 seconds and attain a top speed of 315 km/h (196 mph) as tested by the manufacturer. Additionally, all of the equipment and features from the GT 63, as well as the selectable "Drift Mode", which directs power solely to the rear wheels, comes as standard on the GT 63S as well. A new top-of-the-line variant of the GT 4-Door is reportedly in the works. According to Car Throttle, it is rumored that it will use a hybridized version of the 4.0L Biturbo V8 in the GT 63S.