The Cayenne model line spans five variants: base, S, Turbo, and Turbo S. All models come standard with full-time all-wheel drive with a high and low range. The base is powered by a V6 producing 250 horsepower and comes standard with a six-speed manual transmission or a six-speed automatic transmission with Tiptronic. The Cayenne S comes with Porsche's 4.5-liter dohc V8 engine that delivers 340 horsepower and the Tiptronic automatic. The Cayenne Turbo features a twin-turbocharged version of the V8 rated at 450 horsepower. The Turbo also adds adjustable air suspension with Porsche Active Suspension Management. The new Cayenne Turbo S pumps up the action with a 520-hp version of the twin-turbo V8 mated to the six-speed Tiptronic gearbox.For 2006, the Porsche Cayenne comes in a new Turbo S model and receives other minor changes.