Porsche recently unveiled early drafts of its Cayenne SUV hybrid prototype. The SUV, which will debut towards 2010, aims to decrease fuel consumption by an estimated 25 percent, especially during city driving. The Cayenne Hybrid will feature electric-powered steering, air conditioning and vacuum pumps for the brakes. Porsche officials also report they plan to introduce a hybrid version of its upcoming Panamera four-door Gran Turismo, scheduled to debut in 2009.