Saab History

Saab BioPower Hybrid Concept Adds Two-Mode Hybrid Transmission

· World´s first hybrid capable of running on pure renewable fuel

· State-of-the-art two-mode hybrid transmission

· 260 hp Saab BioPower engine

· Retains full ‘flex-fuel’ capability – gasoline and/or bioethanol

· Zero fossil fuel emissions when running on E100

· Increased performance from torque boosting electric motors

· Fuel saving ‘Zero Mode’ for city driving on electric power only

· Energy saving features include regenerative braking, engine stop/start

· All-wheel-drive capability for improved traction

The latest development of Saab’s innovative combination of BioPower and hybrid technology is presented at the British International Motor Show (July 20 – 30) in London: The Saab BioPower Hybrid Concept.

This unique concept, showcased in a Saab 9-3 Convertible, is the first vehicle to combine a fossil-free bioethanol fuel (E100) capability with electric-only propulsion by utilizing the advanced two-mode hybrid system which General Motors Corp. is co-developing with DaimlerChrysler and BMW Group. The Saab BioPower Hybrid Concept is capable of zero fossil fuel CO2 emissions while also enhancing performance and reducing energy consumption.

Packing 260 hp (191 kW) from the 2.0-liter turbo BioPower engine and a total of 148 kW from its three electric motors, the Saab BioPower Hybrid Concept provides significantly greater torque than its gasoline-only equivalent.

Although it has the potential to run on E100, the all-aluminum 2.0-liter BioPower engine retains a ‘flex-fuel’ capability and can use any combination of gasoline and bioethanol.

The BioPower engine operates in tandem with a sophisticated electric power system, comprised of the two-mode hybrid transmission, a rear-drive unit (RDU), a 300-volt battery and sophisticated electronic control. It offers torque boosting electric power assistance on demand, fuel-saving stop/start functionality, regenerative braking, seamless gear changing from the continuously variable transmission modes and an electric-only ‘Zero Mode’ option for city driving.

Projected performance for the Saab BioPower Hybrid Concept indicates acceleration from zero to 100 kph in just 6.8 seconds, a substantial improvement compared to 9.5 seconds for the equivalent 210 hp gasoline model with a conventional automatic transmission.

“This concept allows us to evaluate and explore the potential of hybrid technology in combination with BioPower,” says Jan Ã…ke Jonsson, Saab Automobile’s Managing Director. “As part of this process, we are now developing our expertise further by introducing the two-mode hybrid technology. It shows how we can continue to express the sporty performance associated with Saab while using renewable resources and saving energy overall.”

Two-Mode hybrid technology

The Saab BioPower Hybrid Concept showcases the state-of-the-art two-mode hybrid transmission. This sophisticated technology represents a major industry milestone, achieving an unprecedented level of integration by combining two electric motors and four fixed gears within a single transmission housing.

Commonly described as a two-mode hybrid due to the low- and high-speed electric continuously variable transmission (ECVT) modes, the fuel-saving technology also incorporates four fixed gear ratios for a total of six operating functions. The result is trend-setting hybrid technology that provides superior fuel economy, performance and load carrying potential.

The two-mode hybrid’s electric motors can be used for electric-only propulsion, boosting the internal combustion engine and providing regenerative braking.

Additional fuel-saving efforts include removing auxiliary functions, such as the water pump, air conditioning and power steering systems, from the engine’s belt drive and transferring them to electric power through the hybrid system.

The two-mode hybrid transmission is similar in size to a conventional automatic transmission. Its adaptable design allows it to be scaled to the size, mass and performance needs of various engines and vehicles.

BioPower propulsion

The Saab 9-5 2.0t BioPower, which is capable of using E85 fuel (85% bioethanol/ 15% gasoline), is an outstanding success in Sweden, where it is currently the best selling flex-fuel vehicle.

The Saab BioPower Hybrid Concept now advances Saab’s alternative fuel technology by adding an E100 capability. The engine is a BioPower evolution of the current all-aluminum, 16-valve 2.0-liter turbo engine in the Saab 9-3 range. Utilizing the higher octane ratings offered by E100, it develops 260 hp and an impressive 375 Nm maximum torque, an increase of 24 percent and 25 percent, respectively, compared to its gasoline-only equivalent.

A Spark Ignited Direct Injection (SIDI) system provides optimum combustion with E100, ensuring the same cold starting performance as a gasoline engine. Variable inlet and exhaust cam phasing is used for optimum air flow and more durable valves and valve seats are fitted, together with bioethanol-compatible materials for the fuel system.

Hybrid architecture

An integrated hybrid operating system has been adopted, where the control strategy is based on efficient ‘energy management’ – recovering and storing energy that is otherwise lost in a conventionally powered vehicle. Apart from converters to manage AC/DC and 12 and 300-volt interfaces, there are three core components: the two-mode hybrid transmission, with two electric motors (described above), an electric Rear Drive Unit (RDU) with a third motor, and a 300-volt battery.

The RDU features a 38 kW motor, located between the rear wheels, which powers a transmission differential and drive shafts. Under acceleration at low speeds, the RDU is able to briefly generate 665 Nm of additional torque. The motor is also configured to provide regenerative braking and energy recovery from the rotating drive shafts during deceleration.

Energy storage for all three electric motors is provided by a high capacity 300-volt lithium-ion battery with fan cooling. This is neatly packaged under the floor of the trunk, without eliminating storage space. Battery performance is carefully monitored and governed by a dedicated electronic control unit.

Driving Benefits

The sophisticated electronic control of the hybrid system is matched to the operating parameters of the BioPower engine to provide performance enhancing power assistance, useful power saving functionality and seamless gear changing.

Under transient driving conditions, a combination of all three electric motors may be activated to augment the power of the engine, increasing standing start acceleration and in-gear performance for safe overtaking – without raising fuel consumption. The driver will also immediately appreciate the smooth operation of the two-mode hybrid transmission.

At take off, the Saab BioPower Hybrid Concept exploits the instant torque of its electric motors, smoothly adding strong, accelerative power during the engine’s pick-up, from tick-over to about 1,500 rpm. During this phase the available pulling power, or torque, of the combustion engine is supplemented by the electric motors of the hybrid system.

Whenever the vehicle is stationary, the engine is immediately shut-off to save fuel. To move off, it is then almost silently restarted by a motor in the two-mode hybrid transmission.

In congested driving conditions, fuel saving is taken a step further by the Saab BioPower Hybrid Concept’s ‘Zero Mode’ option, resulting in zero fuel consumption and zero emissions. It can be selected by the driver via a button in the central console. At speeds below 50 kph, ‘Zero Mode’ will shut off the engine and switch the car over to electric power only from the RDU. In this mode, the battery bank provides a range of between 10 and 20 kilometers. The engine is smoothly re-engaged whenever the battery status approaches a low charge level or the electronic throttle opening requires acceleration beyond the 50 kph operating limit.

Whenever the engine is shut down, auxiliary functions, such as the power steering, air conditioning and lighting, remain unaffected because these are electrically powered by the battery. The removal of unnecessary loadings on the engine further contributes to fuel economy and an extended driving range.

Finally, in low grip road conditions, traction can be optimized by the addition of rear-wheel-drive for improved handling and safety. For example, when the electronic traction control system (TCS) is activated at the front wheels, the car can be balanced by the application of rear drive.

Driver instrumentation for the Saab BioPower Hybrid Concept is as discreet as the installation of its hybrid engineering. In the main instrument cluster, icons are illuminated to indicate when the car is running on engine and/or electric power. An additional gauge shows the power status of the battery. The turbo boost gauge is calibrated by tree icons, a playful reminder of the car’s renewable energy source.

In overall operation, the Saab BioPower Hybrid Concept is designed to deliver enhanced performance and valuable energy savings. The concept enriches driving appeal while also moving further towards the goal of sustainable mobility.

Saab BioPower Hybrid Concept: Technical data:

Vehicle type:

Passenger car concept based on Saab 9-3 Convertible

Configuration:

Transverse engine, front-wheel-drive, electric rear-wheel drive

Two-mode hybrid transmission:

Electric CVT, mechanical lock-up. Two integrated motors, 55 kW/55 kW

2.0 BioPower turbo engine:

Max. power (E100 fuel) 260 hp (191 kW), 375 Nm. Flex-fuel capability

Rear Drive Unit (RDU):

38 kW motor with drive differential to rear wheels

Battery:

300-volt, lithium-ion, fan cooling

Performance:
0-100 kph / 62 mph (simulated): 6.8 secs

Further Information:

Saab is a wholly-owned subsidiary of General Motors, which is committed to reducing vehicle emissions and improving fuel economy through the implementation of a three-tiered, advanced propulsion technology strategy. The ultimate goal is the introduction of hydrogen fuel cell powered vehicles that will emit only water and remove the vehicle from the environmental debate altogether.

In the near to mid-term, hybrid propulsion will bridge the gap between today’s technology and tomorrow’s hydrogen fuel cell powered vehicles.

GM has a diverse hybrid program, with three separate systems designed to provide an opportunity for more consumers to own a hybrid vehicle and benefit from increased fuel savings.

The light-duty two-mode hybrid system is based on the diesel-electric two-mode hybrid system GM has supplied for transit buses since 2003. There currently are more than 455 GM hybrid-powered buses operating in the 38 cities in North America.

The Saturn Vue Green Line SUV, with the new, more affordable GM hybrid system, provides a 20% fuel savings. It goes on sale in the US this summer. Since 2004, GM has sold Chevrolet Silverado and GMC Sierra extended cab full-size pickups with its Light Hybrid system.

GM is also focused on vehicles that run on alternative fuels, such as E85 bioethanol, and is introducing new technologies to improve the efficiency of internal combustion engines and transmissions, further reducing vehicle emissions and increasing fuel economy.

Bioethanol fuel is produced commercially from agricultural crops such as sugarcane, corn and other forms of biomass. When considering CO2 emission savings, the whole chain – feedstock, fuel supply and vehicle combustion – must be considered.

Depending on its source and production process, the use of bioethanol can reduce total CO2 emissions by up to 90% compared to regular fossil gasoline. This is because emissions from its combustion are balanced by an amount of CO2 that is removed from the atmosphere when energy crops are grown. In this way, the CO2 present in the atmosphere remains in a natural cycle, whereas CO2 emissions from the use of a fossil fuel – such as gasoline or diesel – add new CO2 to the atmosphere which has been locked up in oil deposits underground.

2006-03-30

World Premiere at Stockholm Auto Show

Saab BioPower Hybrid Concept: World’s First Fossil-free Hybrid Vehicle

* Innovative hybrid concept based on pure bioethanol
* Zero fossil CO2 emissions in all modes
* 260 hp Saab BioPower engine running on E100 fuel
* Increased performance with threefold torque boost from electric motors
* Fuel saving ‘Zero Mode’ for city driving on electric power only
* Energy saving features including regenerative braking
* Space efficient modular design uses existing vehicle architecture
* All-wheel-drive for improved traction

The innovative Saab BioPower Hybrid Concept, making its world premiere at the Stockholm Motor Show (March 30 – April 9, 2006), delivers zero fossil CO2 emissions, enhanced performance and a range of energy-saving features by combining the use of pure bioethanol fuel and electric power generation for the first time. As the world’s first fossil-free hybrid vehicle, the Saab 9-3 Convertible show car also becomes the world’s first hybrid soft-top.

Packing formidable pulling power from its 260 hp (191 kW) 2.0-liter turbo BioPower engine and 53 kW electric motors, the BioPower Hybrid Concept in the Saab 9-3 can briefly generate torque values three times greater than its gasoline-only equivalent. It is a sporty combination that makes for improved performance, as you would expect from Saab, as well as greater fuel economy and an extended driving range.

Saab’s modular hybrid system features a maintenance-free, 300-volt battery bank, a 38 kW rear-mounted electric motor, a 15 kW integrated starter generator and all-wheel-drive with electric power transmission to the rear wheels. The entire system has been packaged without sacrificing cabin accommodation or trunk space, as demonstrated by its unveiling in the Saab 9-3 Convertible.

The all-aluminum 2.0-liter BioPower engine is modified to run on pure E100 bioethanol fuel, giving zero fossil CO2 exhaust emissions, and operates in tandem with the electrical power system. This offers fuel-saving stop/start functionality, torque boosting electric power assistance on demand, an electric-only ‘Zero Mode’ for city driving and regenerative braking.

The BioPower Hybrid Concept prototype car, a 9-3 sport sedan with automatic transmission, is expected to achieve zero to 100 kph (60 mph) acceleration in just 6.9 seconds, a substantial improvement against 8.8 seconds for the equivalent gasoline model. Even more impressive is 80 to 120 kph (50-75 mph) acceleration on ‘kick-down’ in only 5.5 seconds.

“Hybrids are certainly interesting for Saab in the future and this project allows us to evaluate and explore the potential of hybrid technology in combination with BioPower,” says Jan Ã…ke Jonsson, Saab Automobile’s Managing Director. “Although the exact hybrid application shown in this concept does not currently figure in our production plans, the project has been extremely valuable in helping us further our expertise. It shows how we could develop the sporty performance associated with Saab while using only renewable resources and saving energy overall.”

The Saab BioPower Hybrid Concept is the first project to be announced under a joint investment program between General Motors R&D (Research and Development) and the Swedish government. This has established a research and development office in Trollhättan , Sweden , focusing on vehicle safety, engine emissions and advanced manufacturing in collaboration with Swedish universities, research laboratories and suppliers.

Saab is a 100 percent subsidiary of General Motors, which is committed to reducing vehicle emissions and improving fuel economy through the implementation of a three-tiered, advanced propulsion technology strategy. The ultimate goal is the introduction of hydrogen fuel cell powered vehicles that emit only water and remove the vehicle from the environmental debate.

In the near to mid-term, hybrid propulsion will bridge the gap between today’s technology and tomorrow’s hydrogen fuel cell powered vehicles. GM is also focused on introducing alternative fuels and new technologies to improve the efficiency of internal combustion engines and transmissions, further reducing vehicle emissions and increasing fuel economy.

BioPower propulsion

The Saab 9-5 2.0t BioPower is already an outstanding sales success in Sweden , where it is currently the best selling flex-fuel vehicle on the market and able to exploit a fast-developing network of filling station selling E85 (85% bioethanol/15% gasoline) fuel.

The Saab BioPower Hybrid Concept now goes a step further by using an engine fuelled by pure E100 bioethanol. This is a BioPower evolution of the current all-aluminum, 16-valve 2.0-liter turbo engine in the Saab 9-3 range. It now develops 260 bhp and an impressive 375 Nm maximum torque, 24 per cent and 25 per cent more respectively than on gasoline. The engine incorporates an integrated starter generator (ISG) and also charges a 300-volt battery bank, mounted under the floor of the trunk.

It retains a flex-fuel capability and features a Spark Ignited Direct Injection (SIDI) system for optimumcombustion with E100; ensuring the same cold starting performance as a normal gasoline engine. V ariable inlet and exhaust cam phasing is used for optimum breathing and m ore durable valves and valve seats are fitted, together with bioethanol-compatible materials for the fuel system.

The compact 42-Volt ISG, built into the flywheel between the engine and transmission, is the power behind the Saab BioPower Hybrid Concept’s fuel-saving, stop/start functionality. It serves a multi-functional role as a starter motor, alternator and 15 kW engine power booster, while also helping to iron out residual crankshaft vibrations.

For the Saab BioPower Hybrid Concept application, a series of further steps are taken to optimize the engine’s fuel saving capacity. Auxiliary functions, such as the water pump, air conditioning and power steering systems, are now removed from the engine’s belt drive and electrically powered instead, through the hybrid system.

The five-speed automatic transmission, with Saab Sentronic sequential selection, includes an all-wheel-drive capability by the simultaneous addition of electrically powered drive to the rear wheels.

Hybrid booster

A parallel hybrid system has been adopted, where the control strategy is based on efficient ‘energy management’ – recovering, storing and feeding back energy that is otherwise lost in a vehicle powered only by an internal combustion engine. The engineering team have utilised General Motors’ hybrid experience in the development of stop/start engine functionality, electric rear-wheel drive systems and regenerative braking. Apart from converters to manage AC/DC and 12,42 and 300-volt interfaces, the system consists of just three core components: two electric motors and a battery bank.

Electric energy storage is provided by a 42-cell, 300-volt lithium-ion battery bank. Its performance is carefully monitored and governed by an electronic control unit, through which electric current from the engine is fed.

This power pack is accommodated under the floor of the trunk, without taking up any stowage space, as demonstrated in the Stockholm show car.

The battery supplies a compact 38 kW electric motor located between the rear wheels which powers a transmission differential and drive shafts. At low speeds, this Rear Drive Unit (RDU) is able to briefly generate 666 Nm of additional torque.

In reverse operation, the motor acts as a generator to provide ‘regenerative braking’. It automatically recovers kinetic energy otherwise lost during braking and converts this into additional battery charging. It also performs the same function whenever the driver lifts off the throttle, harnessing the energy in the rotating drive shafts. This is achieved without any perceptible change in the rate of deceleration.

The second electric motor is the integrated starter generator (ISG) located within the flywheel between the engine and main transmission. On demand, it contributes 15 kW of additional power and 120 Nm of extra torque to the output of the engine through the front wheels.

Driving Benefits

The sophisticated electronic control of the hybrid componentry is matched to the operating parameters of the BioPower engine to provide seamless power assistance and power saving functionality.

Under transient driving conditions, both electric motors are activated to augment the power of the engine, increasing standing start acceleration and in-gear performance for safe overtaking. This briefly raises total power by as much as 28 per cent – without raising fuel consumption.

At take off, the Saab BioPower Hybrid Concept also exploits the instant torque generation of its electric motors, smoothly adding strong, accelerative power during the engine’s pick-up, from tick-over to about 1,500 rpm. It is during this phase that the available pulling power, or torque, is more than tripled.

An estimated fuel of saving of 5-7% is provided by the automatic engine stop/start function. Whenever the vehicle is stationary, the engine is immediately shut-off to save fuel. As soon as the brake is released, it is automatically started again by the powerful ISG. The operation is carried out seamlessly and requires no input from the driver.

In congested driving conditions, fuel saving is taken a step further by the Saab BioPower Hybrid Concept’s ‘Zero Mode’ operation – giving zero fuel consumption, and, of course, zero emissions – which can be selected by the driver via a button in the central console. At speeds below 50 kph, ‘Zero Mode’ will shut off the engine and again switch the car over to electric power only through the RDU. In this mode, the battery bank provides a range of between 10 and 20 kilometers (6-12 miles). The engine is smoothly re-engaged whenever the battery status approaches a low charge level or the electronic throttle opening requires acceleration beyond the 50 kph (31 mph) operating limit.

Whenever the engine is shut down, all auxiliary functions, such as the power steering, air conditioning and lighting, remain unaffected because they are now permanently electrically-powered through the battery. The removal of unnecessary loadings on the engine further contributes to fuel economy and in mixed driving the estimated range of Saab 9-3 BioPower Hybrid Concept test vehicles, with a standard 62 liter tank, is a competitive 800 kms.

Finally, in low grip road conditions, traction can be optimized by the addition of rear-wheel-drive for improved handling and safety. For example, when the electronic traction control system (TCS) is activated at the front wheels, the car can be balanced by the application of rear drive.

Driver instrumentation for the Saab BioPower Hybrid Concept is as discreet as the installation of its hybrid engineering. In the main instrument cluster, icons are illuminated to indicate when the car is running on engine and/or electric power. An additional gauge is also fitted to show the power status of the battery bank. Under electric power, the needle will steadily fall and then rise again when the engine provides charging. The turbo boost gauge is calibrated by tree icons, a playful reminder of the car’s renewable energy source.

In overall operation, the Saab BioPower Hybrid Concept is designed to deliver enhanced performance and valuable energy savings. The concept can enrich driving appeal while also moving further towards the goal of sustainable mobility.

Further Information:

GM has a diverse hybrid program , with three separate systems designed to provide an opportunity for more consumers to own a hybrid vehicle and benefit from increased fuel savings. Next year, GM will introduce in the USA the world’s first two-mode hybrid system in the Chevrolet Tahoe and GMC Yukon full-size SUVs. This will be mated with Active Fuel Management TM to deliver a fuel economy improvement of at least 25 per cent. The Saturn Vue Green Line SUV, with a new, more affordable hybrid system giving estimated fuel savings of up to 20 per cent, goes on sale in the US this summer. Hybrid vehicles currently on the US market include the Chevrolet Silverado and GMC Sierra pickup trucks with fuel saving stop/start technology.

Bioethanol fuel is produced commercially from agricultural crops such as sugarcane, corn and other forms of biomass. When considering CO2 emission savings, the whole chain – feedstock, fuel supply and vehicle combustion – must be considered. Dependent on its source and its production process, the use of bioethanol can reduce CO2 emissions up 90% against fossil gasoline. This is because emissions from its combustion are balanced by an amount of CO2 that is removed from the atmosphere when energy crops are grown. In this way, the CO2 present in the atmosphere remains in a natural cycle, whereas CO2 emissions from the use of a fossil fuel – such as gasoline or diesel – add new CO2 to the atmosphere which has been locked up in oil deposits underground.

Saab is a division of General Motors Corp. Saab Automobile USA is the importer and distributor of Saab 9-2X, 9-3, 9-5 cars and the 9-7X SUV for Saab Automobile AB, Sweden.