2011 PORSCHE CAYENNE tire pressure

consistently within a specific
temperature range. The engines
in the Cayenne models are
therefore designed for ef ficient
cooling.
In order to reduce the frictional
losses that occur during warm -up,
all Cayenne models feature com-
prehensive thermal management.
Using intelligent control, it
activates the dif ferent cooling
circuits individually and on de-
mand, thereby ensuring that the
optimum operating temperature
for the engine and transmission
is reached more quickly. This
minimises friction – and keeps
fuel consumption and CO
2 emis-
sions low.
The V8 engines have an enhanced
coolant management system
offering effective temperature
control throughout the engine.
While 20 % of coolant flows longi-
tudinally through the crankcase,
the remaining 80 % serves the
cylinder heads using the proven
cross-flow principle (from hot to
cold).
On all Cayenne models, the piston
heads are cooled using oil-spray
jets integrated within the main
lubrication system.
The entire cooling system is
designed for prolonged heav y-
dut y use, e.g. of f-road driving
or heav y towing and carrying
applications.Lubrication.
The V8 engines use dry-sump
lubrication to ensure a consistent
supply of oil in all load conditions,
especially in of f-road terrain.
The oil reservoir is located inside
the engine. This saves on space
and reduces weight.
Oil is circulated around the V8
engines using a demand- driven
pump. This has been designed
for the toughest driving scenarios
on and off road, including per-
formance driving and extreme
gradients. The V6 engines have a wet-sump
lubrication system.
Ensuring a
reliable supply of oil, no mat ter
how challenging the driving
conditions.
Direct fuel injection on the
diesel engine (common-rail
injection system).
On the Cayenne Diesel, direct
fuel injection comes courtesy of
a common -rail injection system.
The injection pressure is now up
to 2,000 bar, ensuring optimum
distribution of the air/fuel mixture
– for greater performance. The
piezoelectric injectors provide
flexible injection rate
adjustment,
using exactly metered quantities
of fuel, with multiple injections
for each power stroke to deliver
smooth combustion.
Cooling systems.
A high -performance engine can
only maintain its maximum
capabilit y over a long service life
if all components are operating
Direct fuel injection (DFI).
DFI injects fuel directly into the
combustion chamber at up to
120 bar with millisecond precision
using electromagnetic injectors.
The injector position and spray
geometry have been carefully
designed to improve output,
torque, fuel economy and emis-
sions. The swirling of the fuel as
it enters each chamber increases
the mixing of air and fuel, thereby
enhancing combustion. By form-
ing the air/fuel mixture directly
in the combustion chamber, DFI
contributes to engine cooling.
As a result, it was possible to in-
crease the compression ratio and
therefore power and efficiency.

Compression with precision.
Essential for getting right to the point.
38 · Drive systems and chassis | Engine technology

response, even at low revs and
road speeds. This is particularly
useful when driving in urban
traf fic. The supercharger has a
low-temperature water cooling
system for cooling the charge air.
Variable Turbine Geometry in
the Cayenne Diesel.
The turbocharger in the
Cayenne Diesel features Variable
Turbine Geometry (V TG). The
gas-flow from the engine is
channelled onto the turbines via
electronically adjustable guide
vanes. By changing the vane
angle, the system can replicate
the geometry in all t ypes of
turbo, large or small , and thus
achieve the optimum gas-flow characteristics. As a result, even
at low engine rpm, the turbine
speed is maximised. For a sig-
nificant increase in boost pres-
sure, excellent cylinder charging
plus greater power and torque.
Electronic engine management.
Cultured performance in all
driving scenarios requires com-
prehensive engine control. The
electronic engine management
system does this by continually
monitoring the relevant input data
from a variet y of sophisticated
sensors. This data is then com-
pared with a corresponding set of
reference values. Based on this
information, a range of key engine
functions, e.g. ignition and in-
jection timings as well as injection
quantities, are seamlessly and
automatically adjusted. Other
major functions include on -board
recuperation. It ensures that the
on -board power supply is only
replenished while the vehicle is
on the overrun. This boosts fuel
economy as well as performance,
and ensures maximum engine
output during acceleration. All
this goes unnoticed by the driver,
apart from the obvious benefits:
lower fuel consumption and CO
2
emissions plus greater power and
torque at all times.
Exhaust system.
The light weight exhaust systems
in the Cayenne models are made
from special, long-life stainless
steel. The key features of the cata-
lysts are high ef ficiency, faster
warm -up and a long service life.
Sports exhaust system.
Available as an option on the
Cayenne and Cayenne S, the
sports exhaust system
1) provides
an even more distinctive sound.
For the looks to match, it comes
with a specially designed set
of t win dual-tube tailpipes with
a high-gloss finish.
All exhaust systems, standard and
sports, comply with the stringent
EU5 emissions legislation.
2)
Turbocharging system in the
Cayenne Turbo.
In the Cayenne Turbo, the engine
is assisted by t win turbocharger
units arranged in parallel –
one for each bank of cylinders.
Incoming air is passed through
a filter and compressed by the
turbine units. Its temperature is
then reduced in the t win inter-
cooler system, which improves
cylinder charging and limits
thermal loads on the engine.
Supercharging system in the
Cayenne S Hybrid.
The engine in the Cayenne S
Hybrid is equipped with a
supercharger. For a more direct
Air intake system.
The Cayenne models are all
equipped with a resonance air
intake system. This technology
uses the pressure waves
generated by the inlet valves
to ‘force’ air into the engine.
The ef fect is enhanced in the
Cayenne and Cayenne S by a
t wo -stage intake manifold. This
variable geometry combines
all the benefits of a long intake
tube (higher torque at low rpm)
with those of a shorter length
(more power at higher rpm).
The result: highly impressive
torque ratings across the entire
engine speed range.
1 ) For Cayenne only in conjunction with Tiptronic S.2) The data presented here was recorded using the Euro 5 test procedure (715/2007/ EC and 692/2008/ EC) and the NEDC (New European Driving Cycle). The respective figures were not recorded on individual vehicles and do not constitute part of the of fer. This data is provided solely for the purposes of comparison bet ween the respective models. For more information on individual models, please contact your Porsche Centre.
Tailpipes on the Cayenne, Cayenne Diesel, Cayenne S and Cayenne S Hybrid
Tailpipes on the Cayenne Turbo
Drive systems and chassis | Engine technology · 41
Spor ts exhaust system (optional)