Rightsizing with Saab
BioPower and Next-Generation GM Hybrid System
The Saab 9-X BioHybrid demonstrates the potential of
partnering bioethanol fuel with the next-generation GM
Hybrid system to deliver exceptional levels of
efficiency and performance.
Optimized for E85 fuel, the small, 1.4-liter BioPower
turbo engine generates a substantial 200 hp/147 kW on
E85 and an even more impressive 280 Nm (207 lb.ft) of
torque, as well as reduced CO2 emissions compared to
gasoline. With a full flex-fuel capability, it is a
rightsizing formula backed by hybrid technology, giving
projected fuel consumption when running on gasoline
over the combined cycle of just 4.9 l/100 km and 117 g
CO2/km. When running on E85, CO2 emissions are
projected to be even lower, at just 105 g/km, with
estimated fuel consumption of 6.4 l/100 km.
Mated to a six-speed manual gearbox with an automatic
clutch and steering wheel controls, it is a
sophisticated powertrain tailored to meet the
environmental and energy-saving priorities of modern
day motoring.
BioPower Optimized
Saab already leads the automotive
industry in applying its turbocharging expertise to
enhance the performance and environmental benefits of
E85 fuel (85% bioethano/15% gasoline). Saab BioPower
models are the top-selling flex-fuel vehicles in Europe
and produce more power with E85, as well as less CO2
emissions compared to gasoline.
The Saab 9-X BioHybrid now takes this proven BioPower
flex-fuel technology further by using an engine that
fully exploits the high octane benefits of E85 fuel. It
uses a higher compression ratio (10.2: 1) and turbo
boost pressure (up to 1.6 bar) than would be possible
with a gasoline-only engine. This is because E85 has a
higher octane rating (104 RON) than pump gasoline (95
RON), which makes it more resistant to harmful
pre-detonation, or ‘knocking’, as the fuel/air mixture
is compressed in the cylinder.
Whilst optimized for E85, the engine retains a
flex-fuel capability and will still run on gasoline,
although it will not produce as much power. The engine
management system is able to adjust the ignition timing
and boost pressure to ensure there is no pre-detonation
due to the higher compression ratio.
Running on E85 fuel, this lightweight yet sophisticated
BioPower engine delivers the power characteristics of a
much larger powerplant. That impressive torque of 280
Nm (207 lb.ft), for example, is available all the way
from just 1,750 to 5,000 rpm. It’s another
demonstration of Saab’s rightsizing engine strategy –
offering exceptional power without the greater weight,
size, fuel consumption or emissions of a larger,
naturally-aspirated engine.
The advanced specification of this engine also includes
direct injection (DI), with centrally-located fuel
injectors, and continuously variable valve timing (VVT)
on both the inlet and exhaust sides.
DI delivers fuel directly into the combustion chamber
of each cylinder, instead of the intake port. . VVT
then manages airflow by opening and closing the intake
and exhaust valves to improve combustion, and allow the
use of a higher boost pressure. The result is greater
low-end torque and improved fuel consumption. The
central location of the fuel injector, at the top of
the combustion chamber, allows further optimization of
the intake ports for improved engine breathing.
Next-Generation GM Hybrid System
Fuel consumption and CO2 emissions are
reduced still further by the addition of the
next-generation GM Hybrid system, which features a
lithium-ion battery and a significantly higher power
capability to capture more energy and more electric
boost than the current GM Hybrid system. An electric
motor/generator, belt-driven from the engine’s
crankshaft, replaces the conventional alternator.
Electrical power is delivered and stored by the compact
lithium ion battery pack, located under the rear cargo
floor.
The electric motor reacts spontaneously and complements
the torque of the boosted engine. With this combination
of turbocharger technology and a hybrid propulsion
system, the dynamic behaviour of the downsized
powertrain is improved still further.
At take-off from rest and during overtaking manoeuvres,
the electric motor adds accelerative power. It is also
used to re-start the engine, supporting the automatic
fuel-saving function whenever the car is stationary. To
further improve efficiency, the hybrid system enables a
longer fuel cut-off during deceleration and braking.
The electric motor also acts as a generator. It can be
powered by the engine to charge the battery pack and
support vehicle electrical loads. Or it can be used to
capture the vehicle’s kinetic energy when decelerating,
storing that energy in the battery pack. This second
type of charging is commonly known as ‘regenerative
braking’. Sophisticated electronics manage AC/DC and
all voltage interfaces, including the 12-volt in-car
supply.
The combination of GM Hybrid and Saab BioPower
technologies has significant synergies. The hybrid
system adds accelerative power and, in effect, improves
throttle response. This allows further rightsizing of
the engine with additional fuel consumption benefits.
Engine rightsizing and hybridization complement each
other, the combined benefit being greater than that of
the individual technologies.
Responsible Performance
The 9-X BioHybrid also harnesses power
from the sun. The large solar cell in the glass roof
takes advantage of this free energy by adding charge to
the hybrid battery pack while the vehicle is parked and
also when it is being driven.
Apart from saving fuel and energy, responsible
performance means ensuring high standards of safety. In
addition to a full arsenal of electronic stability and
braking systems, the front seats of the 9-X BioHybrid
are fitted with 4-point seatbelts to help hold
occupants firmly in place. The seat-mounted belts are
extended electrically from the sides of the seatback
over each shoulder and are connected together by a
central buckle.
Active safety measures are taken a step further with
the Lane Departure Warning (LDW) function. A
front-mounted camera scans the road ahead and warning
messages are flashed on the driver information display
if the car veers across lane markings. The same camera
is also used to monitor light sources at night. Small
shutters automatically ‘hood’ the high headlamp beam
when on-coming traffic is approaching.