The 911 | Engine
3.8-litre boxer engine
Why it always pays
to take the direct route.
The engine of the 911.
All 911 models feature direct fuel
injection (DFI). The 3.6-litre
horizontally-opposed engine
generates 254 kW (345 hp), and
the 3.8-litre version has an output
of 283 kW (385 hp). The results
are outstanding performance and
surprisingly low fuel consumption
and emission values. All made
possible thanks to DFI, VarioCam
Plus, a lightweight construction,
low friction and a number of
detailed technical solutions.
Direct fuel injection (DFI).
With millisecond precision, DFI
injects fuel at up to 120 bar
directly into the combustion
chamber by means of electro-
magnetically actuated injection
valves.
The spray and cone angles have
been optimised for torque, power
output, fuel consumption and
emissions by enabling a homoge-
neous distribution of the air/fuel
mixture, and, therefore, effective
combustion. With direct injection,
the EMS SDI 3.1 engine control
regulates injection timing individu-
ally for each cylinder as well as
the injection rate for each cylinder
bank. This optimises the combus-
tion process and fuel economy. A
hot-film air mass meter takes care
of the airflow, so that the combus-
tion chambers contain exactly the
right mixture at all times.
At up to 3,200 rpm, the engine
operates with dual injection; at
up to 2,500 rpm, it even works
with triple injection. The required
volume of fuel is distributed
between two or three sequential
injections, respectively – for faster
heating of the catalytic converters
after a cold start and for greater
torque in the upper load range.
DFI improves the internal cooling
of the combustion chamber by
having the mixture prepared
directly in the cylinder. This allows
for a higher compression ratio
(12.5:1) which helps to deliver
more output along with enhanced
engine efficiency. It has been
possible to reduce CO
2
emissions
by up to 15 % compared with the
previous model.
Injection is regulated by the
electronic engine management
system. The exhaust gas cleaning
system ensures that emissions
remain well below even the
strict limits of the Euro 5 emission
standard, thus helping to protect
the environment.
