Four-cylinder fuel efficiency with V8 punch in a full-size SUV? It?s a claim made often, but one Porsche promises to keep with its Cayenne S Hybrid.
Incredibly the Cayenne S Hybrid combines a 6.8 second 0-100km/h sprint with fuel economy below 9.0l/100km, although these figures are Porsche's own and are yet to be verified independently.
The same system is also due to appear in a hybrid version of the Panamera four-door after its official release.
The Cayenne S Hybrid borrows Audi?s 3.0 litre supercharged V6 which produces 248kW (333hp) of power and 438Nm (324lb-ft) of torque and teams it with a three-phase synchronous electric motor that dishes out 39kW (52hp) and 299Nm (221lb-ft).
The electric motor doubles as the alternator and pulls its charge from a nickel-metal hydride battery which weighs only 70kg (154lb) and fits into the spare wheel well.
The hybrid system is able to run on either petrol power or electricity alone, or a combination of the two. The electric motor can run without assistance from the petrol engine at speeds up to 138km/h (86mph) and distances up to 1.9km (1.2 miles). A regenerative braking system restores charge to the battery pack which can also be topped up by the petrol engine at highway speeds.
Other green-enhancing features include an electric air conditioning compressor and electric power steering as well as a Porsche-first eight-speed automatic gearbox designed to reduce engine revs in seventh and eighth gear.
Overall, Porsche claims a 20 percent reduction in CO2 emissions compared to vehicles with a similar power output. The Cayenne S Hybrid also qualifies for Ultra Low Emissions Vehicle II (ULEVII) status.
The visual styling of the Cayenne S Hybrid remains unchanged and the hybrid drive system is easily accommodated into the existing Cayenne structure. The Cayenne S Hybrid is due to go on sale sometime in 2010 for Europe and America.