The German automotive industry is not just busy lowering fuel consumption, it is also developing more effective ways of reducing harmful emissions. Since 1970 emissions have been cut by 95 per cent, with Porsche always adopting a pioneering role.
In 1966, the emissions testing department carried out tests on other manufacturers’ export vehicles on behalf of the US Environmental Protection Agency (EPA) on the rolling test rig at Porsche.
By 1979, the US version of the 911 was the first high-performance sports car with a regulation catalytic converter.
Since three-way catalytic converters were introduced for petrol-engine vehicles, Porsche has made many advances. Thanks to this technology, the environmental impact of emissions, such as hydrocarbons, carbon dioxide and nitrogen oxides, has been reduced to a minimum.
The Cayenne models are equipped with the very latest in emissions technology. As a result, they comply with the stringent EURO 4 emissions standard as well as the EV2 – LEV (Cayenne and Cayenne Turbo) and LEV2 – ULEV (Cayenne S) regulations in the United States. This is made possible in part by a system of primary and secondary catalytic converters on each of the two exhaust lines. Each catalytic converter has a rapid warm-up cycle so emissions are reduced sooner when starting from cold.
Another key factor in lowering emissions is the use of stereo lambda control circuits. Each bank of cylinders has a separate control system used by theengine management system to establish the optimal air/fuel mix and monitor the efficiency of the catalytic converters.
Fuel consumption/emissions* of the Cayenne models: Urban in l/100 km 15.8 l-8.7 l; Extra urban in l/100 km 8.4 l-6.6 l; Combined in l/100 km 11.5 l-7.4 l; CO2 emissions in g/km 270 g-195 g.