A new generation of the Mercedes-Benz S-Class was revealed last September, but the version most Motor Authority readers will be interested in, the Mercedes-Benz AMG S63, was notably missing.

That's because AMG has some major changes pegged for its full-size super sedan, a prototype for which has been spotted again. The tester has all the signature AMG cues like four square-shaped exhaust tips, lowered suspension, and a performance tire and brake package.

The new S63 will become a plug-in hybrid, most likely badged a S63e, and it should eventually be joined by a new S73e replacing the old V-12-powered S65. Crucially, both variants will feature a V-8-based plug-in hybrid system.

A similar powertrain setup is expected to be fitted to both the S63e and S73e, specifically a 4.0-liter twin-turbocharged V-8 paired with a single electric motor and drive sent to all four wheels. The setup, good for a maximum 804 hp, should debut shortly in a new range-topping GT 4-Door Coupe variant.

Mercedes-AMG E Performance

Mercedes-AMG E Performance

The S63e should have a version with around 700 hp, with 134 hp coming from the electric motor. The S73e should have the full 804 hp, with its electric motor generating 201 hp. The outgoing S63 has 603 hp while the last S65 came with 621 hp, so we should be looking at a huge step in performance. A pure electric range is expected with the new setup as well.

There will be a weight penalty due to all the extra hardware, but performance of the new S63e should match or exceed the outgoing model, with fewer emissions produced. The outgoing S63 will hit 62 mph in just 3.5 seconds and top out at a governed 186 mph (155 mph standard).

2022 Mercedes-Benz AMG S63e spy shots - Photo credit: S. Baldauf/SB-Medien

2022 Mercedes-Benz AMG S63e spy shots - Photo credit: S. Baldauf/SB-Medien

While AMG no longer offers a V-12, S-Class buyers seeking the big engine will be able to opt for it in the new Mercedes-Maybach S-Class.

Here in the United States, the new S-Class arrived in showrooms this spring as a 2021 model, and right now there are only S500 and S580 grades. The Maybach S-Class arrives in mid-2021 and the first AMG version should arrive in late 2021 or early the following year.