Mercedes-AMG recently teased a new flagship model based on the AMG GT 4-Door. This new variant will be known as the GT 73e and will be faster than the GT 63 S, which produces 630 horsepower and 664 lb-ft of torque. The GT 63 S is already more potent than the BMW M5 CS, but the GT 73e should bring AMG to new heights with a rumored 800 hp rating thanks to a 4.0-liter twin-turbocharged V8 mated with a plug-in hybrid drivetrain. And since the AMG division loves to share its engines among multiple models, the GT 4-Door may not be the only car to spawn a 73 variant.

CarBuzz discovered a new trademark from Daimler AG with the USPTO for the name "E 73." This is the first time we've spotted this name, and based on other recent filings from Mercedes, we're inclined to believe this one could become a production model that will sit above the current Mercedes-AMG E63.

The AMG GT 4-Door rides on the same platform as the E-Class, so it seems likely that the company's new 73 PHEV powertrain could easily fit into both cars. As of now, neither of AMG's direct German rivals have created hybrid versions of their performance sedans. Before the current version debuted, Audi was reported to be working on a 700-hp hybrid RS7, but those rumors have not turned out to be true. No similar rumors have emerged about a hybrid BMW M5.

The Porsche Panamera Turbo S E-Hybrid is the only electrified competitor in this space, now producing 689 hp and 642 lb-ft of torque after a recent update. If the GT 73e and E73 arrive sporting anywhere near the rumored 800 hp figure, they could crush the RS7, M5, and Panamera in one fell swoop.

It's interesting to note that the E73 trademark doesn't feature a lower case "e" at the end, as the GT 73e. Perhaps this is to avoid the confusion of an E73e, or maybe the E73 won't be a hybrid, but rather a more hardcore E63 variant akin to the M5 CS. It could also be a meaningless exclusion, as the original GT 73 trademark filing also lacked the lower case "e." Mercedes already has live trademarks for "SL73," "G73," and "S73," hinting that a range of 73-powered cars is in the works.