Porsche boss Michael Macht says that staff in the firm are fully committed to building the 918 Spyder, the biggest shock - and hit - of the Geneva motor show.

Taken from drawing to show car in under five months, the 918 mixes a 500bhp petrol V8 with two electric motors for a combined 718bhp. Porsche has calculated that it could be quicker than the old Carrera GT around the Nordschleife.

See the Porsche 918 Spyder gallery

Porsche has yet to commit to producing the car - but speaking to Autocar, Macht admitted that the positive reaction to the 918 had already swayed opinion within the firm.

"There is no one inside Porsche who doesn't want to build the 918," he said. "The response has been marvellous; we will ask buyers to sign letters of intent.

"The 918 Spyder provides the answer to whether there can be high-performance cars in the future," he added. "Many have said they are finished. This car shows they are not."

Insiders say the production 918 is likely to go on sale within five years. However, like all Porsches, it will need to make money, despite its 'halo' status within the firm's range.

Macht also denied that a hybrid version of the Cayenne would damage sales of the diesel variant, which made its world debut at Geneva. "The Cayenne hybrid will account for about 15 per cent of sales," he said, "and appeal to customers who use their cars mostly in urban areas. We believe the hybrid sales will be incremental, and the diesel will be better at rural and highway use, where people need its cruising economy and high gearing."

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