Porsche CAYENNE Brochure page 52

Fuel economy. Fuel system.
At Porsche, we're using innovative We have also applied the highest
technologies to increase perform- engineering standards to protect
ance while enhancing fuel economy. the environment from fuel
With direct fuel injection (DFI), evaporation. The non-return
we've made our engines more fuel supply system provides a
efficient in terms of both output considerable reduction in vapour
and consumption. DFI is combined emissions. The fuel lines are
with VarioCam Plus in the V8 engines partly constructed from steel,
and variable valve timing in the while those carrying vapour are
Cayenne V6. As well as improving made from multi-layer plastics.
performance and economy, both A large active-carbon filter and
of these systems help to minimise multi-layer plastic fuel tank help
engine emissions. The low-drag reduce evaporation even more.
exterior on each Cayenne model A leak detection pump is also
further improves efficiency. included to monitor the integrity
of the fuel tank system.
Fuel.
Acoustics.
All Porsche models are already
compatible with a fuel ethanol Think of a Porsche and what
content of up to 10 %. Ethanol do you hear? One of the most
has a positive impact on the carbon distinctive sounds on the road.
dioxide balance since the plants A sound created not just by the
grown for its production absorb engine, but also by the absence
carbon dioxide from the atmosphere. of unwanted noise. To minimise
'play' between engine components
under all load conditions, we've
used stronger, lighter and more
temperature-resistant materials.
This reduces mechanical noise
and eliminates the need for engine
encapsulation. Large-volume
silencers and air intake manifolds
also help to minimise noise –
throughout the life of the car.
Tyre noise has been drastically
reduced in collaboration with
our official tyre partners. Wind
noise levels have also been
lowered thanks to aerodynamic
refinements.
All that remains is the Porsche
sound – as legendary as ever.
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Environment