Reports that the Peugeot 508 successor is underway appears on track for a projected 2018 debut, as our spy photographers have spotted a test mule undergoing road trials. There is little to disclose regarding what’s under the skin of the new car, though it is expected to use the company’s now-commonplace EMP2 architecture.

Judging from these images, the 508 replacement will have wider stance, though not quite the four-door coupé in the mould of the Peugeot Exalt concept of 2014. Though concealed, Peugeot’s contender against the likes of the VW Passat and Ford Mondeo could perhaps carry over certain design cues from the show car.

Here, we can see that the test mule reprises the dual-exhaust layout seen currently, and the rear bootlid appears to sport a more squared-off upper edge, possibly even a little spoiler lip. Panel lines aren’t evident just yet, though the rear three-quarter treatment appears to offer sleeker design compared to the more traditional three-box silhouette of the current car.

Power units aren’t confirmed, though with the use of the EMP2 platform it is likely that the next 508 could kick off proceedings with the existing range of 1.6 litre turbocharged THP petrol inline-four and HDI 2.2 litre turbodiesel engines, with any update to the range likely after the car has arrived on the market.

GALLERY: Peugeot Exalt Concept