New Porsche's weight loss comes with a cost

Porsche's latest offering in New Zealand is a curious mix of cutting-edge and clumsy, in that it sheds weight to aid fuel economy and dynamic performance but comes with a clip-on canvas soft-top that wouldn't be lost on a 1950s MG.

The two-seat Boxster Spyder is the lightest car in the Porsche line-up, weighing 1275kg, or around 80kg less than the Boxster S. It gets a more powerful version of the Boxster's 3.4-litre engine, too, the direct-injection flat-six delivering 235kW, or 7kW more than the Boxster S, thanks to remapped software.

The result is an exciting performance blend of more power shifting less weight and a lowered, wider and firmer suspension set-up complementing nimble dynamics.

That's on a good road surface, where the Spyder seems to respond to throttle inputs and a change of direction marginally quicker than other Boxsters.

The drive isn't as rewarding on bad ground, where the suspension crashes and bangs around. A softer set-up would compromise the whole package.

The Spyder has been designed mainly as an open-top car, like the line of Porsche Spyders stretching back 50-odd years.

Engineers focused on shedding weight. The new sports seats save 12kg. The alloy wheels save 2kg. Ditching cup holders, replacing the door handles with red fabric pulls, and trimming interior materials saves 15kg. Aluminium in the doors also helps.

But the biggest weight reduction has been brought about by the new canvas roof, also the car's most controversial feature.

It saves 21kg but is not operated electrically, as on the regular car. Porsche admits the clip-on canvas offers less weather protection. It also recommends owners remove it on track days, or if speeds exceed 200km/h.

The arrangement consists of a weather shield behind the seats and a cap of sorts that stretches over the top, attached via two securing rings set into the rear bodywork.

It looks complex and takes time to fix it into position.

Weather sealing is basic, too, the odd raindrop finding its way into the cabin. Expect wind noise at highway speeds.

The six-speed manual Spyder costs $149,900; the PDK double-clutch version $155,900.