Since the new Mercedes-AMG SL was unveiled, we’ve known that a plug-in hybrid variant was coming, and now we can see it in all its glory as an uncamouflaged test car was spotted during some cold-weather testing. The PHEV nature of this particular test car is betrayed by the charge port door on the rear bumper, though that would appear to be the only major difference between this and the regular AMG SL with conventional engines. Since Mercedes has already shown the SL to the world, the need for any camouflage is no longer present.

We already know that the new SL is based on the same platform as the upcoming AMG GT Coupe. That ought to excite the power-hungry because this car shares the four-door AMG GT’s hybrid powertrain that makes a ton of power. In the AMG GT 63 E Performance, motivation comes from a 4.0-liter twin-turbocharged V8 that is hooked up to an electric motor on the rear axle. Together, they make a combined 831 hp and 1,400 Nm of torque. The electric motor is integrated with a two-speed transmission and an electronically controlled limited-slip diff to ensure better grip and performance.

 

The AMG GT 63 E Performance is good for a 0-60 time of just 2.9 seconds and a top speed of 315 km/h, as well as 27 mpg (8.6 L/100 km). Since this two-door roadster is smaller than the sedan, it might be lighter and capable of accelerating faster, though Mercedes-AMG may also be limited by the car’s space for batteries. Some sources have reported that we could see two plug-in hybrid variants, potentially named SL63e with around 700-hp and a full-fat SL63 E-Performance with the afformentioned 831-hp.

The new Mercedes-AMG SL was revealed last October and is currently sold with two V8 options. The SL 55 makes 470 hp, while the SL 63 makes 577 hp. Both get a nine-speed automatic transmission. There’s also talk about an entry-level SL43 model powered by the A45 S’ 2.0-liter turbocharged four making around 385 hp with the help of a mild-hybrid system. No date has been officially set for the plug-in hybrid roadster’s unveiling but a debut is expected before the year’s end.