When the Mercedes-Benz AMG GT Concept bowed in 2017 as a preview of the GT 4-Door Coupe, the striking show car was said to boast a powerful electrified V-8 under the hood. So far, such a powertrain hasn't taken shape, but it appears that will soon change.

AMG on Thursday released a photo of a new GT 4-Door Coupe variant due to be revealed on September 1 ahead of a formal debut the following week at the new Munich auto show. The new variant is expected to be a plug-in hybrid range-topper, the first in the line of electrified AMGs carrying the new E Performance branding. The One hypercar was meant to be the first but delays have pushed back its launch.

The GT 4-Door Coupe plug-in hybrid will now have that honor. It is expected to carry a new GT 73 designation, though GT 63e has also been rumored. What we do know is that its powertrain will feature a 4.0-liter twin-turbocharged V-8 mated to a 9-speed automatic up front and a single electric motor mated to a 2-speed transmission at the rear.

There will also be a 6.1-kilowatt-hour battery kept charged primarily to provide power during high-performance driving, though a small electric range will also be possible. Drive will be to all four wheels via a conventional all-wheel-drive system.

Mercedes-AMG E Performance

Mercedes-AMG E Performance

Mercedes-AMG E Performance battery

Mercedes-AMG E Performance battery

Peak output of the system is expected to be 804 hp. Currently, the GT 4-Door Coupe tops out with the GT 63 S, whose output is 630 hp. With so much extra juice, the 0-60 mph time should slip under 3.0 seconds. The GT 63 S has already been clocked at 3.2 seconds.

Eager buyers should expect a premium price for the extra performance. The GT 63 S already starts at $159,995. For this kind of money, buyers could also opt for the Porsche Panamera Turbo S E-Hybrid, also a plug-in hybrid, or the battery-electric Porsche Taycan Turbo S. There's also the Tesla Model S Plaid and upcoming Lucid Air Dream Edition Performance, both of which deliver more than 1,000 hp.

AMG doesn't have an answer to those electric super sedans just yet, though a tamer AMG-tuned EQS is due out later this year. We should also see it in Munich.

The Munich auto show replaces Germany's traditional auto show held in Frankfurt. It starts Sept. 6, and you can catch our full coverage via our dedicated hub.