. Engine of the Year: Award for the 2.0 TFSI Audi
engine
Ingolstadt - Audi's
pioneering achievements in the domain of petrol injection technology are
not restricted to success on the racetrack. The 2.0 TFSI has now been
awarded the title of "Engine of the Year". Audi is the first
manufacturer in the world to combine petrol direct injection with
turbocharging in the spheres of both motor racing and volume production.
The 2.0 TFSI embarked on its
success story in the Audi A3 Sportback. It is now also on offer in the
Audi A4 and A6. It is available in three performance versions ranging from
170 bhp to 220 bhp. The 200 bhp version, which is used in the Volkswagen
Golf GTI, provides a level of propulsive power that truly befits that
car's status.
The jury praised the Audi
engine, which dominates the engine displacement category from 1.8 to two
litres, for its good "balance between technology, performance,
economy and environmental acceptability". The jurors were also
impressed by its pulling power and high level of everyday suitability. The
exceptionally broad torque plateau on the one hand permits a
fuel-efficient driving style with few gearshifts, and on the other hand
means that only light accelerator action is needed to produce assertive
thrust and a spontaneous unleashing of power.
With FSI technology, fuel is
injected directly into the combustion chamber. The injector, located on
the admission side in the cylinder head, is served by a high-pressure pump
driven by the camshaft and a pressure reservoir shared by all cylinders -
the common rail system.
The injector regulates fuel
delivery with millisecond precision, at injection pressures of up to 110
bar. By comparison, a manifold injection system operates at between four
and six bar.
Two balancing shafts rotating
at double the speed of the crankshaft compensate for the engine's inertial
forces and also achieve a high standard of acoustic comfort. The results
are outstanding for a four-cylinder engine.
The intake manifold
integrates the charge movement flaps, the position of which is adjusted by
a continuous-action pilot motor. The movement of the airflow, or tumble,
can thus be controlled optimally on the basis of the engine-speed and load
conditions.
The fuel-air mixture is
distributed homogeneously within the combustion chamber. A spontaneous
power build-up and an agile response at every point along the broad
engine-speed band are the positive consequences.
The four-valve cylinder head
with low-friction roller cam follower valve gear has an inlet duct
geometry that has been modified from that of the naturally-aspirated FSI
engine, producing even higher tumble values. This results in both greater
refinement and superior knock resistance, and therefore improved
efficiency.
The result is that the turbo
engine achieves a compression ratio of 10.5:1, a figure that is otherwise
typically achieved only by naturally-aspirated engines. This, coupled with
the advantages of petrol direct injection, plays a crucial role in
boosting the thermodynamic efficiency compared with both manifold
injection engines and conventional turbo engines.
