The next-generation 911 Turbo, the 992, has been spotted testing, here seen wearing 991-generation bodywork. It seems that the new car will be larger than the current model, with wheelarch extensions seen on this development unit expected to house wheels and tyres of even greater dimensions.

Even higher levels of grip can be expected, which, in turn, should have even more power and torque exploiting them. With the current model cranking out 580 hp in Turbo S guise, the 992 model could breach the 600 hp mark relatively easily. Performance benchmarks are also expected to be further raised beyond the current 911 Turbo S’ 2.9-second 0-100 km/h time and 330 km/h top speed.

Underneath the familiar bodywork is said to be a new, modular platform which is set to be shared with other sports cars within the larger Volkswagen Group, such as the next Audi R8 and the successor to the Lamborghini Huracan. The new modular platform upon which the new car will be based could also form the basis of Porsche’s mid-engined supercar to contend with the likes of the Ferrari 488 GTB and McLaren 720S.

Expect further innovations in engine tech, beyond the variable geometry turbines and charge pressure maintenance for improved transition of throttle over the current model. In the chassis department, rear-wheel steering can also be expected to help aid both high-speed stability and low-speed agility, as at present. The next-generation 911 is expected to debut in 2018 at the soonest, and the Turbo variants should follow shortly after.

GALLERY: 991-generation Porsche 911 Turbo coupe and cabriolet