A new-generation Mercedes-AMG GT is coming. That's no secret, as we've captured plenty of prototypes on camera. The mystery surrounding the new performance coupe isn't how it looks, but rather, what's under the bonnet.

We have a new set of spy images showing a blue AMG GT test vehicle, and if you're experiencing deja vu right now, it's okay. We shared images of another GT prototype less than 24 hours ago, wearing a similar camouflage pattern amid a snowy landscape. However, that car was green and at the back, it had four rectangular exhaust tips – a telltale feature reserved for the most powerful AMG models. It also had a visible charging port, suggesting it packed a plug-in hybrid powertrain. You won't find either of those items on the car featured in our photo gallery below, which also hides a milder front fascia beneath the camo wrap.

Gallery: Mercedes-AMG GT 53 Spy Photos

Oval-shaped quad exhaust finishers are typically associated with entry-level AMG vehicles, and as such, this could be a Mercedes-AMG GT 43. We say that because this car doesn't appear to have any charging ports, making it a pure combustion-powered coupe. We've seen other camouflaged prototypes with round exhaust tips and a charging point, which could indicate a mid-level AMG GT 53. That leaves room for an AMG GT 63 model, leading the way with a powerful PHEV powertrain.

The big question, then, is what's under the bonnet for these AMG trims? We've heard everything from 4.0-litre V8 engines with and without hybrid assist, to Merc's turbocharged four-cylinder hybrid, and even the turbo-four without hybrid assist. With this particular test vehicle looking like an entry-level model, it could wield the M139 turbocharged 2.0-litre four-cylinder making 384 bhp and 354 pound-feet of torque. That's what comes with the Mercedes-AMG SL 43, and the new AMG GT is slated to be a fixed-roof companion to the SL. Meanwhile, the other end of the spectrum could see a wild AMG GT with over 800 bhp.

We expect the mystery to be solved later this year, so stay tuned for more Mercedes action. You can always check out the Rambling About Cars podcast for the latest car news, mixed with a dash of wit for your entertainment.