Long roof C63 is underway, but without a V8.

We all know that the new Mercedes-AMG C63 is coming sooner or later, especially that the regular Mercedes C-Class has already made its debut earlier this year. Its long-roof version is also already in its developmental phase, and we have a new set of spy photos as evidence to that assumption.

Of note, this isn't the first time we've seen the C63 Estate prototype; we've seen it around the Scandinavian region before for its cold weather tests. This time around, the hot estate is seen testing near the Nurburgring.

Gallery: Mercedes-AMG C63 Estate New Spy Shots

Just like the previous prototype, the camouflaged tester here comes with a mismatched set of wheels – one pair's black Y-spoke, while the other's a silver twin-spoke – probably to throw off spy photographers to capture any latest detail. What Mercedes couldn't hide, though, is the more aggressive styling found on the bumpers and, of course, the Panamericana grille.

While most of the design updates for the AMG C63 Estate and the rest of the C63 range aren't extensive, we all know that there will be a massive change inside that bonnet.

In an interview, C-Class chief engineer Christian Früh has confirmed that the C63 will lose the biturbo V8 in favour of a hybrid setup in conjunction with a four-pot mill.

Later reports surfaced, confirming that the next AMG C63's hybrid powertrain will be developing 550 bhp (410 kilowatts) and 590 pound-feet (800 Newton-metres) of torque, which makes it a tad more powerful than the outgoing model C63 S. That, of course, in the expense of heavier body weight.

Of course, these details aren't officially official, which will happen by the time the new C63 lineup will be revealed by the end of this year. The C63 Estate spied here will be revealed shortly after, both expected to hit showrooms for the 2022 model year.