Compared with a naturally aspirated engine of
identical power output, the fuel consumption of a turbo engine is lower, as some
of the normally wasted exhaust energy contributes to the engine's efficiency.
Due to the lower volumetric displacement of the turbo engine, frictional and
thermal losses are less.
The power-to-weight ratio, i.e. kilowatt
(power output)/kilograms (engine weight), of the exhaust gas turbocharged engine
is much better than that of the naturally aspirated engine.
The turbo engine's installation space
requirement is smaller than that of a naturally aspirated engine with the same
power output.
A turbocharged engine's torque characteristic
can be improved. Due to the so-called "maxi dyne characteristic" (a very high
torque increase at low engine speeds), close to full power output is maintained
well below rated engine speed. Therefore, climbing a hill requires fewer gear
changes and speed loss is lower.
The high-altitude performance of a
turbocharged engine is significantly better. Because of the lower air pressure
at high altitudes, the power loss of a naturally aspirated engine is
considerable. In contrast, the performance of the turbine improves at altitude
as a result of the greater pressure difference between the virtually constant
pressure upstream of the turbine and the lower ambient pressure at outlet. The
lower air density at the compressor inlet is largely equalized. Hence, the
engine has barely any power loss.
Because of reduced overall size, the
sound-radiating outer surface of a turbo engine is smaller, it is therefore less
noisy than a naturally aspirated engine with identical output. The turbocharger
itself acts as an additional silencer
