It’s been a busy month for BMW at the Nürburgring. The challenging German track nicknamed by Jackie Stewart as “The Green Hell” served as the venue for prototype testing of several models. We’ve talked about the next 3 Series (G50), i3 Sedan (NA0), and the new iX3 (NA5), but there was another car. This unassuming M5 F90 was spotted during industry-pool testing, so this isn’t an enthusiast’s sports sedan.

Judging by the Munich plates, it might just be BMW’s own prototype unless it’s being tested by a supplier. Ok, but what makes it interesting? It may look like a standard previous-generation M5 before the facelift, but there’s a subtle change at the rear. The fender extensions indicate it’s a test mule for … something. Obviously, the M5 F90 isn’t coming back, so we’re scratching our heads trying to figure out what’s what.

The plot thickens when you consider BMW is already testing the facelifted M5. Although G90 deliveries kicked off only a few months ago, car paparazzi have already caught the LCI with Neue Klasse design cues on camera. This M5 F90 might not necessarily be a test mule for a future product. The engineers could be evaluating specific components that will eventually go (or not) into a road-going model.

The extra thickness over the M5’s already bulging fenders makes us think it’s a test mule for an SUV. However, we wouldn’t go as far as to say the next X5 M is hiding underneath the sedan’s body. Curiously, the fender flare seems more pronounced on the driver’s side. It’s always tricky to pinpoint the identity of test mules, especially if they carry the body of a car that BMW no longer makes. Whatever the case, the vehicle clearly has a combustion engine, likely a big V8.

The M division has pledged to keep the eight-cylinder alive for the long haul, and we’ve already reported about BMW engineering the new X5, X6, and X7 with V8s. Just about everyone would want an M5 G90 with an S68 that skips the bulky plug-in hybrid setup. However, that ship has long sailed. We’re just glad to see BMW’s relentless efforts to save the V8 in the downsizing era. Hopefully, this mysterious test mule is a sign of an exciting M product currently in the works. Fingers crossed.

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