At the heart of the Spyder sits Porsche’s new 4.0-litre flat six, with 414bhp and 310lb ft. Despite possessing similar displacement, this is not a detuned version of the motorsport-grade, 9000rpm engine you’ll find in the 911 GT3 but a development of the 3.0-litre twin-turbo unit used by the latest 911 Carrera S. The old Boxster Spyder also used an engine from the contemporary Carrera S, although in that case the 375bhp 3.8-litre was directly swapped without undergoing major changes.

Here, the 9A2EVO unit has been bored, stroked, relinquished of its turbochargers and fitted with new cylinder heads, pistons, valves and con-rods. The crankshaft is also new and spins to 8000rpm. You may wonder why Porsche has gone to all this trouble when it already has an awesome 4.0-litre six at its disposal, and the reasons are twofold.

Its action might not be quite as slick as that manual gearbox, but even the cupholder feels as though it has been built to an impeccable standard. The engineering that has gone into this car is just mega.

First, with a 911 GT3-spec engine, the cost of the car would have been considerably higher, perhaps more than £100,000. Second, for a mid-engined application, that engine would have needed to be switched around 180deg, leaving no space for the external oil reservoir.

The engine’s efforts are put through a short-throw six-speed manual gearbox attached to a dual-mass flywheel from the 911 GT3 and then to the rear wheels via a mechanical limited-slip differential.

This is the first time the 718 Spyder has benefited from the same underpinnings as the track day-focused Cayman GT4, which itself is said to be some 12sec quicker around the Nordschleife than its predecessor.

Just three of those seconds are down to the new engine. The rest are accountable to the lightweight strut suspension, which uses the same inverted dampers, control arms and ball joints as the 911 GT3. The subframes are also from Porsche’s iconic GT car. Compared with the regular Boxster, then, the 718 Spyder sits 30mm closer to the ground and it touts a generous front splitter and rear diffuser, which are unique to the most rarefied of 718 models.

The result is not a heavy car but neither is it one quite so light as we’d have hoped. At 1420kg, the 718 Spyder is more than 100kg heavier than its forebear, despite retaining its manually folding canvas roof. Its power-to-weight ratio is strong, though, at 292bhp per tonne – more than the 911 Carrera S Cabriolet.


Find an Autocar review

Find an Autocar car review