Mercedes has just unveiled the new generation SL-Class in three different trims: SL 43, SL 55, and SL 63. But the work is far from done, as more hybrid models are also under development. We've already spotted the SL63 E-Performance out for testing, and now it seems that Mercedes will also offer a second hybrid option, but with less power. The new model, most likely set to be named SL 53 PHEV, was caught testing in the Austrian Alps free of camouflage.

How is the SL53 E-Performance Different from the SL63 E-Performance?

The prototype our spy photographers spotted today has the charger port placed in the rear bumper - the only indication this is a hybrid model - while the exhaust system ends with round quad pipes. The SL 63e prototype features fluted trapezoidal twin exhaust tailpipes, but as you know the round pipes are for less powerful models. The rest of the exterior look is pretty much identical to a standard SL, but we expect to see more updates in the final product.

What will power the new Mercedes-AMG SL53 PHEV?

The more powerful SL 63e is rumored to be offered with the same powertrain as the GT 63S E high-performance sedan: a 4.0-liter V-8 gasoline engine combined with an electric motor that powers the rear wheels. This system should deliver up to 800 horsepower in the SL63 E-Performance. For the less powerful, SL 53e PHEV things will be a little bit different. There will be no V-8 under the hood. Instead, Mercedes will go for the same powertrain that will be found in the upcoming Mercedes AMG C63. This means the two models will combine the company’s new turbocharged 2.0-liter M139 engine with an electric motor that powers the rear axle. But, while in the C63 this system is rumored to deliver around 670 horsepower, in the SL 53e it will be detuned to about 400 - 450 horsepower. And that's because as its name suggests, the SL 53e will be placed above the SL 43, but under the current SL 55 in the lineup, with the latter delivering a total of 469 horsepower. We expect the next SL 55e PHEV to go from 0 to 60 mph in just 4.0 seconds, with top speed being limited to the usual 155 mph.

When will the Mercedes-AMG SL53 PHEV debut?

Just like with the SL 63e, we expect the new SL 53e to be unveiled before the end of 2022, or early in 2023. Sales will start shortly after, and prices should be in the $140k range.