2008 PORSCHE 911 GT2 fuel consumption

· 15 · · 14 ·The 911 GT2 |
The 911 GT2
Drive is transmitted through a pre-
cision six-speed manual gearbox.
Rear-wheel drive provides driving
dynamics that are similar to those
of a racing car. In the 911 GT2,
Porsche also uses a special system
for conventional manual transmis-
sion: the Launch Assistant (see
page 38) – for maximum accelera-
tion from a standing start.
For a sporty but still comfortable
drive, particularly for this type of
sportscar, the standard suspension
features variable damping providedby Porsche Active Suspension
Management (PASM, see page 48).
This active damping system offers
a wide range of benefits including
greater performance and comfort.
Also standard is Porsche Stability
Management (PSM, see page 50).
For the first time, the integrated
control systems for lateral and lon-
gitudinal dynamics, stability control
(SC) and traction control (TC) can
be fully disabled in two stages for a
more natural drive. This means thecar can also be enjoyed to maxi-
mum effect on the racetrack.
The one-piece 19-inch GT2 alloy
wheels of the 911 GT2 are fitted
with road-legal sports tyres as
standard. In size 325/30 ZR 19 on
the rear, these are 20 mm larger
than on the 911 Turbo. The special
tread and compound enable
tremendous lateral acceleration
and higher cornering speeds as
well as precision handling and
turn-in characteristics on either
road or racetrack. A range ofsetup options is available for
racing use, including ride height,
camber, toe angle and front/rear
anti-roll bars.
Developed in motorsport, and
standard on the 911 GT2 is the
Porsche Ceramic Composite
Brake (PCCB, see page 58).
The discs are made from specially
treated carbon fibre and are
approximately 50 % lighter than
comparable metal alternatives.
The results: better brake perfor-mance, greater agility and lower
fuel consumption.
Sports bucket seats (see page 72)
with folding backrest, integral
thorax airbag and manual fore/aft
adjustment, are fitted as standard.
A perfect driving position is essen-
tial in a car with the performance
potential of the 911 GT2. The latest
Porsche Communication Manage-
ment (PCM, see page 76) is also
fitted as standard. This features
a new 6.5-inch touchscreen for
intuitive control.We believe that you don’t have
to exploit the full potential of
the 911 GT2. But you may well
choose to.

· 26 ·· 27 ·
The 911 GT2 |Drive
VarioCam Plus
Engine cooling.
The engine of the 911 GT2 features
cross-flow water cooling with fully
integrated coolant management.
This technology ensures a consis-
tent flow of coolant to each of
the engine’s cylinders. Waste
heat from the oil is transferred to
the coolant via two oil/water heat
exchangers. The coolant is routed
through twin radiator modules
ahead of the front wheels and a
centrally placed unit in the nose.
VarioCam Plus.
VarioCam Plus is a variable valve
timing system on the inlet side
which also features two-stage valve
lift. The benefits it provides include
greater power and torque at all
engine speeds, as well as excellent
running characteristics, better fuel
economy and fewer emissions.
Essentially, VarioCam Plus makes
two engines out of one. The first is
geared for normal road driving, thesecond for high-performance use.
The system switches seamlessly
between the two as the driver
inputs change. All operations
are controlled by the engine
management system. The results:
emphatic acceleration and
smoother running.
The two-stage lift mechanism
on each inlet valve consists of an
electro-hydraulically switchable
tappet. Each of the 12 tappets con-
sists of two concentric parts – anouter ring and a central shaft –
which can be locked together by
means of a pin. The system can
then vary the valve lift by using
two large profile cams on the outer
ring or a smaller cam lobe on the
central shaft. The timing of each
valve is steplessly controlled by
means of an electro-hydraulic
rotary vane adjuster at the head
of the corresponding camshaft.
To improve responsiveness during
warm-up in cold weather, VarioCam
Plus will select the higher valve
lift setting and retard valve timing.
At medium revs and low engine
loads, the lower valve lift setting
is activated and timing advanced in
order to reduce fuel consumption
and emissions. The economy of
the engine is particularly enhanced
at lower engine speeds. For maxi-
mum power and torque, the higher
lift setting is selected and the tim-
ing of the valves is advanced.This results in copious torque
and exceptional fuel economy,
particularly in comparison with
much larger engines offering
similar power output.

· 31 · · 30 ·
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The 911 GT2 |Drive
1. Turbine casing
2. Movable guide vanes
3. Turbine wheel
4. Electric motor for guide
vane adjustment
5. Guide vane adjuster
6. Compressor casing
7. Compressor wheel
8. Recirculation valve
9. Oil inlet
10. Coolant inlet
Guide vanes open Guide vanes closed
Guide vanes open Guide vanes closedTurbocharger guide vane adjuster
To overcome this problem, the
twin water-cooled turbochargers
on the 911 GT2 feature Variable
Turbine Geometry (VTG). With
this technology, the gas-flow
from the engine is channelled
onto the turbines via electronically
adjustable guide vanes. By chang-
ing the vane angle, the system
can replicate the geometry in all
types of turbo, large or small,
and thus achieve the optimum
gas-flow characteristics. The guide
vanes are controlled by the engine
management system. The result
is a high turbine speed – and
therefore higher boost pressure –
even at low engine rpm. With
more air available, the combustion
is increased, yielding greater
power and torque.
Special features on the 911 GT2
include flow-optimised turbines
and larger compressors which
generate a higher boost pressure.
Maximum torque is
achieved at
low rpm and sustained across
much of the engine speed
range.With 680 Nm available between
2,200 and 4,500 rpm, the
resulting acceleration is nothing
less than phenomenal.
When the boost pressure reaches
its maximum value, the guide
vanes are opened further. By
varying the vane angle, it is
possible to generate the required
boost pressure at all engine
speeds. As a result, there is no
need for excess pres
sure valveson the intake side as found
on
conventional turbocharged
engines.
This delivers impressive
engine efficiency and lower
fuel consumption.

· 33 · · 32 ·The 911 GT2 |
Drive
Unfortunately, compression not
only increases air volume, it also
increases air temperature and this
has a negative effect on ignition.
Our new expansion manifold simply
turns that principle around. The
internal geometry is radically
different from that on a resonance
intake system. Key modifications
include a longer distributor pipe,
with a smaller diameter, and
shorter intake pipes.Expansion intake manifold.
More power than a 911 Turbo -–
from the same engine? Not easy.
But feasible, which is why it
required yet another spectacular
innovation from Porsche.
The 911 GT2 has an innovative
expansion intake system with a
unique working principle which
overturns the methods previously
used. Our ‘expansion’ intake
mani-
fold is a radical new
developmentthat is the polar opposite of
the resonance principle used
on conventional turbocharged
engines.
A resonance manifold increases
engine output by forcing add-
itional air into the combustion
chambers. To do this, the mani-
fold is designed in such a way
that the air – which vibrates
due to the action of the valves –
is in a compression phase as it
passes through the inlet ports.As a result, the air is in the
expansion phase as it enters the
combustion chambers. Since
expansion always cools, the
air/fuel temperature is lower and
ignition is significantly improved –
thereby increasing performance.
Of course, the amount of air
that enters the engine under
expansion is less than it would
be under compression. To
compensate for this, we’ve simply
increased the boost pressurefrom the turbochargers by
approximately 0.2 bar. The result-
ing increase in temperature –
again through compression – is
immediately offset by the uprated
intercoolers.
Instead of hot compressed
air entering the combustion
chambers, we now have cooler
air generating more power and
torque. As a consequence,
there is a major improvement in
engine efficiency and thereforelower fuel consumption even under
heavy loads and at high rpm.
A simple solution, but then that’s
often the way when you take
a new approach to old ideas.
Expansion intake manifold

· 34 ·· 35 ·
The 911 GT2 |Drive
Exhaust system.
The rear silencer and tailpipes
of the 911 GT2 are made from
ultra-lightweight titanium to re-
duce the weight on the rear axle,
and improve driving dynamics.
The exhaust leaves the engine
through high-performance
manifolds into separate tracts
for each of the two banks of
cylinders. Twin three-way catalytic
converters clean the two streams
before they converge in the main
silencer unit. The twin
titaniumtailpipes are fully integrated
within
the rear apron moulding. Large-
diameter tubes reduce back-
pressure
on the engine,thereby
increasing performance. The
catalytic
converters are close
to the engine,
enabling faster
warm-up and therefore improving
efficiency. When starting from
cold, the process is assisted by a
secondary air injection system.
A system of ‘Lambda’ or oxygen
sensors in each of the exhausts
provides continuous monitoring of engine efficiency. Data supplied
by one pair of sensors enables
the engine management system
to perform separate adjustment
of the air/fuel mix for each bank
of cylinders. A further pair of sen-
sors*, one on each tract, is used
to monitor the efficiency of the
respective catalytic converter. This
facility enables much more accu-
rate control of potentially harmful
emissions.
The exhaust system on the
911 GT2 produces a warm,
deep and bass-rich sound –
even when the engine is idling.
Fuel system.
Fuel is supplied to each of the six
cylinders using a sequential fuel
injection system. The timing of
each injection and the volume
supplied to each bank of cylinders
are controlled by the engine
management system. Adjustmentsare based on a range of variables,
including throttle position, engine
speed, boost pressure, coolant
temperature and exhaust gas com-
position. The results are optimised
combustion and fuel consumption.
A hot-film air mass sensor moni-
tors the volume and density of the
incoming air to ensure the best
possible air/fuel mix, regardless
of weather and altitude.
Ignition system.
The 911 GT2 features static
high-voltage ignition technology.
Separate coils on each of the
plugs with platinum electrodes
ensure perfect ignition every
time. The role of distributor is
performed by the engine manage-
ment system, which controls the
individual spark plugs directly,
for optimum performance and
minimum fuel consumption.
* Not in markets with leaded fuel.Exhaust system

· 69 · · 68 ·
The 911 GT2 |Comfort
the rev counter. A centrally placed,
clearly visible arrow indicates the
latest time to change gear.
On-board computer.
The integral on-board computer
gives information on boost pres-
sure, average fuel consumption,
speed, remaining distance andexterior temperature. It can also
be used to view data from the
standard Tyre Pressure Monitoring
(TPM) as well as the timing system
featured in the optional Chrono
Package Plus (see page 75).
The computer is operated using
a control stalk on the steering col-
umn, with information displayed in
the instrument cluster.
Instruments.
The sporting credentials of the
911 GT2 refer not only to engine
and chassis, it also boasts a sporty
interior designed around the driver.A car like the 911 GT2 requires
an ergonomically efficient driving
environment with unhindered
access to all key information.
Clearly visible at the centre of
the cluster of five instruments is a large rev counter with GT2
logo and titanium-coloured dial.
The needles and markings in the
instrument cluster are yellow.
For optimum acceleration, you
can view the upshift display in Other standard features include
automatic air conditioning with
active carbon filter.
We’ve demanded your respect. Now have ours.
Interior.

· 85 · · 84 ·
The 911 GT2 |Environment
Here, all technological developments
are carried out with environmental
protection in mind. The aim: pure
performance – but not at the
expense of the environment.
You can find more information
about environmental matters in the
separate brochure ‘Porsche and
the Environment’, or on our website
www.porsche.com.
Exhaust emission control.
The 911 GT2 easily meets the strin-
gent emissions standards for the
EU4 regulations in Europe and
LEV II regulations in the USA. This
demonstrates that even high per-
formance sports cars can achieve
moderate emissions values in their
respective categories. The 911 GT2
is not only one of the most power-
ful cars around, but also one of the
cleanest. One pair of sensors is
used to monitor the oxygen levels
in each of the twin exhaust tracts.
An additional pair of sensors* –
again, one on each tract – is
located downstream from the cat-alytic converters. This information
is used by the engine management
system to monitor the efficiency of
the catalysts.
Fuel.
The current Porsche sportscar
model range is already compatible
with fuels that have an ethanol
content of up to 10 %. A ‘biofuel’
made from naturally replenishing
materials, ethanol has a positive
impact on the carbon dioxide bal-
ance since the plants grown for its
production also absorb carbon
dioxide from the atmosphere.
Fuel system.
In the fuel supply system, we’ve
minimised the evaporation of
hydrocarbons. This is achieved
through a combination of active
carbon filter and special fuel-tank
coating. All fuel lines are made
from aluminium, while those
carrying vapours are made from
multi-layer plastic.
* Not featured in markets with leaded fuel.
Noise.
The 911 GT2 complies with all
noise regulations in the respective
markets. Rather than resorting
to engine encapsulation, we’ve
eliminated noise at source. All that
remains are the powerful acoustics
you’d expect from a thoroughbred
Porsche.
Servicing.
Longer service intervals are not
only easier on resources, they also
reduce ownership costs.
For service intervals of the 911 GT2,
please refer to the price list.
In an era of intensifying debate
about CO
2emissions, every auto-
motive manufacturer is considering
how to deal with the question of
fuel consumption. Our answer has
long been the same: maximum
efficiency.
Porsche reduces the CO2emissions
of its vehicles annually by an aver-
age of 1.7 %. In relation to engine
power, Porsche is already among
those manufacturers achieving the
lowest CO
2emissions. This has
been achieved through an efficient
drive concept, optimised aero-dynamics, low rolling resistance
and lightweight construction.
This high degree of environmental
responsibility is clearly demonstrated
by our approach to environmental
management at the Porsche
development centre in Weissach.
Powerful performance needn’t cost the earth.
Environment.

· 107 · · 106 ·
The 911 GT2 |Technical data
Technical data
Engine
Cylinders6
Displacement3,600 cm3
Max. power (DIN)390 kW (530 hp)
at rpm6,500
Max. torque680 Nm
at rpm2,200 – 4,500
Compression ratio9.0 : 1
Transmission
LayoutRear-wheel drive
Manual gearbox6-speed
Chassis
Front axleMcPherson-strut suspension
Rear axleLSA multi-link suspension
SteeringVariable steering ratio,
power-assisted (hydraulic)
Turning circle10.9 m
BrakesPorsche Ceramic Composite Brake (PCCB):
6-piston monobloc aluminium fixed calipers
at front, 4-piston monobloc aluminium fixed
calipers at rear, discs internally vented and
cross-drilled
Vehicle stability systemPSM
Anti-lock braking systemABS 8.0
WheelsFront: 8.5J x 19 ET 53
Rear: 12J x 19 ET 51
Ty r e sFront: 235/35 ZR 19 (sport tyres)
Rear: 325/30 ZR 19 (sport tyres)
Weights
Unladen weight (DIN)1,440 kg
Unladen weight (EC)*1,515 kg
Permissible gross weight1,750 kg
Performance
Top speed329 km / h (204 mph)
0 –100 km / h (0 – 62 mph)3.7 secs
0 –160 km / h (0 – 99 mph)7.4 secs
0 – 200 km / h (0 –124 mph)11.2 secs
Flexibility 80 –120 km / h (50 –75 mph) 4.1 secs
in 5th gear
Fuel consumption/emissions**
In accordance with 80 / 1268 /EC as valid at the time of going to print
Urban in l / 100 km (mpg)18.8 (15.0)
Extra urban in l / 100 km (mpg)8.9 (31.7)
Combined in l / 100 km (mpg)12.5 (22.6)
CO2emissions in g /km298
Dimensions /aerodynamics
Length4,469 mm
Width1,852 mm
Height1,285 mm
Wheelbase2,350 mm
Luggage compartment volume105 litres
Tank capacity (refill volume)90 litres
Drag coefficient0.32
** Weight is calculated in accordance with the relevant EC Directives and is valid for standard specification vehicles only.
Optional equipment means greater weight. The figure given includes 68 kg for the driver and 7 kg for luggage.
** The figures given refer to vehicles with standard specification in Germany. Data determined in the NEDC (New European Driving Cycle) in accor-
dance with the EU5 (80/1268/ EEC) measurement method in the version valid at time of going to print. The figures do not relate to an individual
vehicle, nor do they constitute part of the offer. They are intended solely as a means of comparing different types of vehicle. Further information
on the individual vehicles can be obtained from your Porsche Centre.