Mercedes introduced the previous-generation E-Class Coupe (C207) more than 10 years ago and retired it back in 2017, so why would they be testing a car no longer on sale? That’s because we are pretty sure this is a mule for something else, although we can’t pinpoint what Mercedes was actually testing with this intriguing car equipped with a roll cage at the Nürburgring.

We’re tempted to say AMG is working on a new engine judging by what sounds like a V8 rumble. When you think about it, this is kind of ironic seeing as how the promised AMG E63 Coupe never actually happened during the C207’s life cycle. We have yet to see one based on the current E-Class Coupe as the range tops out with the electrified E53, but that’s a story for another day.

If this is indeed a new V8, there’s a pretty good chance it won’t power the next-generation AMG C63 considering there’s a wild rumour going on about the car downsizing to a hybrid four-cylinder. If the report turns out to be accurate, it means the folks from Affalterbach will install the eight-cylinder mill only in the larger models above the C63.

Some might be tempted to say we’re looking at the all-new SL taking into account it has already been spotted hiding underneath a shortened E-Class Saloon of the current generation. Whatever Mercedes/AMG is testing, it sure sounds like the V8 still has a bright future up ahead. We can’t say the same thing about the V12 as the engine is being gradually retired, although it might still power some of the Maybach models for a limited amount of time.

Meanwhile, it is believed BMW is also working on a new V8 slated to debut in the M5 CS, possibly with a smaller displacement than the current 4.4-litre unit but with more power than the already available 617 bhp. For the sake of comparison, AMG’s V8 tops out at 630 bhp in the GT 63 S. The other member of the German luxury trio, Audi, recently introduced the RS6 Avant with a twin-turbo V8 pushing out 591 bhp, but more power could be on the way courtesy of a plug-in powertrain based on the 4.0-litre unit.

AMG will also electrify its V8 next year when a new range-topping GT Four-Door Coupe – possibly called GT 73 – which is expected to offer a combined output of approximately 800 bhp.