The Mercedes-AMG GT has returned to the Nurburgring after the new Porsche Panamera Turbo S stole the 63’s crown as the fastest executive car, this time in the most powerful spec yet: the AMG GT 73.

In development for the better part of the year, the plug-in hybrid model is probably warming up before attempting to break the lap record on the famous German racetrack. To do so, it will have to complete the full circuit length of 20.832 km (12.944 miles) in less than 7:29.81.

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It’s been rumored that the GT 73 might use AMG’s twin-turbo, 4.0-liter V8 engine with an electric motor mounted at the rear for a total output of over 800 horsepower. This would eclipse not only the twin-turbo 4.0-liter V8 of the ‘Ring record holder, the Panamera Turbo S, that’s rated at 621 HP, but also the Panamera Turbo S E-Hybrid’s 670 HP, or rumored 750+ HP in the facelifted iteration. It would also give it a 170+ HP advantage over the GT 63 S 4Matic+.

Considering that the current range-topper of the series, the GT 63, does the 0 to 62 mph (0-100 km/h) in just 3.2 seconds and has a 195 mph (315 km/h) top speed, the GT 73 will likely drop the sprint time to under 3.0 seconds.

Not much has changed visually compared to the GT 63, as the 73 sports the big Panamericana grille up front, large air intakes, a rear spoiler and a camouflaged rear bumper that probably hides the charge port, said to have been positioned under the left taillight.

Mercedes will probably unveil the new AMG GT 73 before the end of 2020.