The 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 assuming 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 standard 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.

Exhaust emissions and fuel consumption

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 LEV2 – 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.

Changes in legislation on car exhaust emissions in Europe in g/km

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 the engine management system to establish the optimal air/fuel mix and monitor the efficiency of the catalytic converters.