Porsche Cayman User Handbook Manual page 92

Top marks for cleanliness.
In an era of intensifying debate
about global climate change and
CO emissions, every automotive
2
manufacturer is asking itself
what it has to offer in terms
of environmental protection. Our
answer has long been the same:
maximum efficiency.
Over the last 15 years, Porsche
has managed to reduce the
fuel consumption of its vehicles
by an average of 1.7 % each year.
Improvements in fuel economy
also have a beneficial impact
on CO emissions. In relation to
2
power output (g/km per hp),
Porsche is already among those
manufacturers achieving the
lowest CO emissions. This has
2
been achieved through an efficient
drive concept (DFI), lightweight
construction, optimum aerody-
namics and low rolling resistance.
1)
Not in markets with leaded fuel.
100
This high level of environmental
responsibility is clearly demon-
strated by our approach to
environmental management at the
Porsche development centre in
Weissach. Here, all technological
developments are carried out
with environmental protection in
mind. The goal? Pure perform-
ance – but not at the expense of
the environment. A goal achieved
by the Cayman models.
Exhaust emission control.
Both engines comply with stringent
emission standards, including Euro 5
in Europe and LEV II/ULEV in
the USA. Vehicles manufactured
by Porsche demonstrate that even
high-performance sportscars
can achieve moderate emission
values in their respective category.
In short, the Cayman is not only
extremely sporty, it is also very
clean.
This attribute is achieved by
means of a two-stage cascade-
type catalytic converter
which comprises two monolith
substrates on each of the twin
exhaust tracts. These specially
coated substrates contain
ultra-fine honeycomb channels in
which pollutants are converted
as exhaust gas passes through.
The stereo Lambda control
circuitry controls and monitors
each cylinder bank separately,
while another Lambda sensor
on each cylinder bank monitors
pollutant conversion in the respec-
tive catalytic converter (p. 44).
1)