Mercedes-AMG is gearing up to give its biggest GT model, the 4-Door, a mid-life refresh.
An AMG GT 4-Door mule has been snapped testing wearing camouflage on its front end, suggesting new details are coming. Although the car gained new wheel designs and colour options in 2021, its bodywork wasn’t tweaked.
Expect to see new detailing in the bumpers and grille, and potentially new vents on the fenders. Although the headlights on this particular car aren’t disguised, our spy agency has suggested they may appear on later mules.
We’re expecting an all-new AMG GT (two-door) based on the same architecture as the Mercedes-AMG SL in 2023, so any update to the 4-Door would likely pull its styling into line with its new, smaller brother.
The GT 4-Door goes head-to-head with the Audi RS7 and BMW 8 Series Gran Coupe.
Along with a few new wheel options and colours, the GT 4-Door gained a new entry-level 53 model, and a plug-in hybrid 63 S E Performance flagship.
The former won’t be coming to Australia; the latter is on track to arrive before the end of 2022.
The GT 63 S E Performance blends a 4.0-litre twin-turbo V8 engine with an electric motor for 620kW of power and a staggering 1400Nm of torque.
Mercedes-AMG hasn’t really designed the GT 63 to be a Prius, but it’ll still do 12km on electric power alone.
The 150kW/320Nm e-motor is on the rear axle, where it’s combined with a two-speed transmission and an electronic limited-slip differential.
GT 63 S E Performance 
First gear takes the motor from standstill to around 140km/h, at which point it’s spinning at around 13,500rpm.
The lithium-ion battery feeding it is mounted below the boot floor.
Although it’s mounted on the rear axle, the electric motor is mechanically linked to the car’s all-wheel drive system, so it can shuffle torque between the axles as required.
Along with the plug-in hybrid system, the petrol engine features a 48V mild-hybrid system.
GT 63 S E Performance 
The 100km/h sprint flies by in 2.9 seconds, the 200km/h sprint takes less than 10 seconds, and flat out you’ll be doing 316km/h.
There are plenty of challenges associated with making a hybrid go (very) fast, chief among which is cooling.
Mercedes-AMG says it uses a sophisticated liquid cooling system to keep the lithium-ion battery at 45 degrees celsius, no matter how hard you’re flogging the GT 63 on track.
