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Super efficient and powerful, the 9-3 Aero TTiD boasts a
unique two-stage turbocharging system, which was a world ‘first’ in the premium
car segment.
Matched to either a six-speed manual or six-speed automatic
transmission, the 1.9-litre, 16-valve two-stage turbo engine puts the
performance and efficiency of the Aero TTiD among the best in its
class.
The responsible performer delivers a sporty
drive with 132 kW and 400 Nm of maximum torque, in gear performance similar to
the 9-3 petrol Aero and a frugal combined 5.7 litres per 100km for the manual
Sport Sedan model.1
The Saab TTiD engine meets a growing demand from drivers
unwilling to sacrifice performance in the interests of fuel economy. With power
characteristics typical of a much larger engine, it is an example of Saab’s
commitment to ‘right-sizing’, the achievement of ‘big’ engine performance
without the usual drawbacks, such as extra weight, bulk and higher fuel
consumption.
Pricing
Saab 9-3 Aero TTiD is competitively priced in the premium
segment, with recommended retail price excluding dealer delivery and government
charges as follows:
Aero TTiD Power/Torque RRP Fuel consumption
(Combined)
Sport Sedan manual 132kW/400Nm $62,600 5.7l/100km
Sport Sedan auto 132kW/370Nm $65,100 6.8l/100km
SportCombi manual 132kW/400Nm $65,100 5.8l/100km
SportCombi auto 132kW/370Nm $67,600 6.9l/100km
Two-stage turbocharging
The two-stage turbocharger housing is integrated with the
exhaust manifold and contains two turbochargers of different sizes. The pair of
turbine/compressor wheels are sequentially mounted and each is able to by-pass
the input and output feeds of the other, while also being able to operate in
tandem.
This arrangement provides a driver with the best of both
worlds - good, instant torque at low engine speeds - via the low-inertia small
turbo when the exhaust pressure is light - and strong ‘top end’ power at higher
revolutions, when the larger turbo is engaged.
1 Performance and economy figures based on ECE/ ADR 81/01
regulations
Saab’s two-stage turbocharging uses a
system of by-pass valves that directs the exhaust gas stream between the two
turbine wheels and also separates the air intake charge from the
compressors.
From tick-over to 1,500 rpm the exhaust feeds only the small
turbo. Between 1,500 and 3,000 rpm the flow is split between both turbines,
giving stronger boost and ensuring a smooth transition phase to full power
operation, above 3,000 rpm, when only the larger turbo is engaged.
The compact design provides more efficient packaging than
systems using two separate turbochargers linked together externally in series.
It ensures that the complex control and regulation of gas flows on both the
exhaust turbine and intake compressor sides is achieved with a minimal number of
seals and connections.
TTiD engine
The TTiD engine is a substantial development of the current
16-valve 1.9TiD unit, using common rail, direct and multiple fuel injection. It
operates with a maximum boost pressure of 1.8 bar (1.4 bar for the current
engine) together with a slightly lower compression ratio of 16.5: 1 (17.5:1).
The cast-iron block, alloy cylinder head and all internal components are
strengthened as necessary to withstand the higher thermal
pressures.
The exhaust gas re-circulation (EGR) system
is characterized by extremely efficient cooling and now includes an
electronically controlled by-pass, and a low-maintenance exhaust particulate
filter for improved emissions.
Other technical enhancements include the adoption of a larger
air-to-air intercooler, for better cooling of the intake charge; the
introduction of more efficient pre-heating elements inside the cylinder head,
for faster starting in cold conditions; and the use of a weight saving plastic
intake manifold.
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