Standing a mere 1418mm tall and featuring short overhangs at the front and rear, it retains a sporting stance that distances the Panamera from its saloon car rivals

Porsche has released the first undisguised pictures of its four-door saloon Panamera Gran Turismo. The fastback has been conceived to do battle with the BMW M5 and Mercedes-Benz E55 AMG.

It's a substantial car, taking a bigger footprint than the Cayenne SUV, measuring in at 1931mm x 4970mm. Standing a mere 1418mm tall and featuring short overhangs at the front and rear, it retains a sporting stance that distances the Panamera from its saloon car rivals. There's a sizeable luggage compartment which can be extended by folding down the rear seat backrests.

The Panamera will be powered by six- and eight-cylinder engines which will deliver between 300 and 500bhp. Some engines will use turbochargers, and they will be mated to either a manual six-speed gearbox or the Porsche seven-speed auto. The Panamera will be rear-wheel-drive but higher-spec models will come in all-wheel drive. All-wheel-drive is also available as option on lower-spec models.

Porsche is also planning a fuel-efficient version of the Panamera with hybrid drive. Porsche is hoping to sell around 20,000 Panameras worldwide and the car will make its debut in spring 2009: the first models will be arriving in Porsche Centres worldwide in late summer.