Possible 4-cylinder prototypes of the Porsche Boxster and the Cayman have been spied once again while being tested on the Nurbirgring

Possible 4-cylinder prototypes of the Porsche Boxster and the Cayman have been spied once again while being tested on the Nurburgring.

Similar vehicles were caught on camera at the beginning of this month featuring the same engine sound. We can’t say for sure the prototypes from the video are powered by flat-four units, but judging by the unusual sound in question it seems testing of the firm's newly developed boxer motor has started. Furthermore, back in May Porsche chief Matthias Müller confirmed such an engine for both models is already in the works.

A report from June has suggested the German manufacturer’s new 4-cylinder engine lineup will come in three displacements and all of them will feature a direct injection and will be turbocharged. The portfolio will consists of a 1.6 with 210 bhp (156 kW), a 2.0 that is expected to develop 286 bhp (213 kW) and 399 Nm (295 lb-ft) and a range-topping 2.5 with rumored 360 bhp (268 kW) and 470 Nm (347 lb-ft).