Set to debut this March at Geneva is the production version of the Mercedes-AMG GT concept, and it stands to be the fiercest rival the Porsche Panamera has ever had. The concept is stunning in the flesh and in pictures, so there's no question AMG designers know what they're doing. Need further proof? The Mercedes-AMG GT. But Autocar has learned the production sedan is going to be extremely powerful and, therefore, extremely fast. Sources told the publication the range-topping hybrid variant will produce a ridiculous 805 hp.

It'll even have an all-electric range of 31 miles. However, this gasoline-electric powerplant supposedly won't be available at launch. We'll have to wait until 2019 for that. What will be offered from the get-go is a twin-turbocharged 4.0-liter V8 with 604 hp, the very same engine found in the E63 S. The sexy four-door coupe will also have the 4Matic all-wheel drive system and nine-speed automatic transmission. Not exactly a lightweight. That 805-hp range topper, however, won't be the only hybrid version offered. Apparently, Mercedes has plans to develop that hybrid driveline with three levels of battery capabilities. This way, engineers can play around with varying power outputs and driving ranges.

But don't think for a moment that any of these "lesser" hybrid variants are going to be bland. For example, the base hybrid driveline will produce 671 hp with a 19-mile range, while the mid-level will produce 736 hp and offer a 25-mile range. All hybrid versions will come powered by the same twin-turbo 4.0-liter V8 from the non-hybrid launch version, but there'll be an electric motor bolted within the rear axle. At the moment, the most powerful Porsche Panamera you can buy is the 680-hp Turbo S Sport E-Hybrid, which also has a 31-mile all-electric driving range. But does the fact the base Mercedes-AMG sedan, sans batteries, will offer 604 hp from day one spell trouble for the folks at Stuttgart? The Mission E would be Porsche's reply to that.