SPY PICS: Boxer-six fix for Porsche Cayman GT4

Purists upset with the demise of six-cylinder Porsche Caymans be heartened: The upcoming 718 series Cayman GT4 looks set to pack a six-cylinder boxer engine displacing 4.0-litres and punching out something in the region of 300kW. The outgoing 3.8-litre six-cylinder Cayman GT4 produced 283kW.

These spy photographs show an essentially undisguised GT4 prototype cavorting in the snow during the European winter. Dual outboard exhaust outlets hint at the six-cylinder powerhouse lurking within. The not-just-for-show rear spoiler looks to be a GT4 carryover, while the overall profile of the rear bumper, including the diffuser aperture, appears identical to other 718 series Porsches. Come production time and that may change, however.

Word on the grapevine suggests the pride of the Cayman fleet will also get revised frontal architecture as well as a reworked rear end. The front end shows there will be some more serious aero work, including way-bigger outer air intakes, while there's also some significant lowering that plays a role in cramming the wheel arches to their limits with oversize wheels and super low-profile tyres. Composite brake rotors and red callipers seen lurking behind the multi-spoke wheels look entirely serious and speak of track-readiness.

It is anticipated that the 4.0-litre engine will be a detuned version of the 368kW boxer six used in the latest 911 GT3 – which is also expected to donate the GT4 Cayman's new six-speed manual gearbox. Even before the four-cylinder 718 Cayman went on sale there were allegations that there would be a six-cylinder Cayman sooner or later.

It's rumoured that the GT4 will also get a suspension makeover to lift its potential above that of the outgoing car, while also helping deal with the extra power. Scuttlebutt concerning the possibility of Porsche's dual-clutch PDK gearbox being on the GT4 options list is also doing the rounds.

Speculation differs, but sources are saying the new Cayman GT4 won't arrive on overseas markets until the end of 2018, or maybe early in 2019. The latter would seem plausible for Australia.