Holden's Green Car

This article was first published in 2000.

Holden has unveiled a leading edge concept vehicle that uses up to 50 per cent less fuel than a conventional family car and dramatically reduces exhaust emissions. The advanced hybrid-electric powered ECOmmodore has been developed jointly by Holden and CSIRO and is designed with the emphasis on practicality and achievable technology. It is the first hybrid-electric vehicle to be produced by an Australian automotive manufacturer and is the only one of its type in the world.

Like the top-selling Holden Commodore it is based on, the ECOmmodore is a full-sized family car. Its unique hybrid-electric powertrain - which combines an electric motor powered by supercapacitors and advanced lead-acid batteries with a four-cylinder aluminium alloy petrol engine - delivers the same level of performance as a standard 3.8 litre V6. The ECOmmodore's technologies are specifically targeted at improving overall vehicle efficiency. These include significant mass reduction through the use of advanced, lightweight materials, clever aerodynamics, reduced rolling resistance and regenerative braking.

Holden Chairman and Managing Director, Peter Hanenberger, says the ECOmmodore illustrates the high level of technological innovation that is achievable in Australia.

"It is a rolling showcase of all-Australian ingenuity. The ECOmmodore incorporates some of the materials, components and manufacturing technologies that will be needed in the future. It also demonstrates that hybrid technology can conceivably be used in a large family car at a realistic cost," he said. "The ECOmmodore is a recognition of the increasing influence that social and environmental issues are bringing to bear on the uptake of new technologies. While it is not a prototype for the next model Commodore, it provides our engineers with a hands-on learning tool to experiment with emerging technologies that will be incorporated into Holden vehicles in coming decades," Mr Hanenberger concluded.

A major aim of the Holden/CSIRO ECOmmodore project was to demonstrate that a full- sized family car can meet future fuel consumption and emissions requirements without compromising the safety and engine performance of the current Commodore.

Supporting Holden's role as Team Millennium Partner for the Sydney 2000 Olympic Games and Provider to the Sydney 2000 Olympic Torch Relay, the ECOmmodore will make its on-road debut in the opening leg of the Olympic Torch Relay at Uluru on 8 June. It has been nominated as the official guest relations vehicle in the Torch Relay convoy during its first day and will carry a VIP guest, yet to be named by SOCOG.

Reducing Energy Wastage

The low-emission ECOmmodore derives its remarkable fuel efficiency and performance capabilities from a number of sources. Holden and CSIRO engineers and technicians began by focusing their abilities on reducing the estimated 87 per cent in energy wastage that occurs during normal suburban driving. They targeted stringent fuel consumption goals by reducing the energy needed during acceleration and cruising, reclaiming some of the energy lost during braking and improving engine efficiency.

Lightweight Materials

Weight reduction was a major focus. Without compromising on safety, performance and comfort levels, significant gains were made by using high-strength, lightweight materials to form an efficient body structure. The floor is constructed in embossed aluminium: stronger than normal steel flooring and one-third the weight. Other panels are made from carbon fibre and fibreglass; all windows, with the exception of the windscreen are polycarbonate. Seats and door trims are lightweight, as are the steering column and suspension system. Brake system mass is significantly reduced via lightweight calipers and an electrically operated parking brake.

Slippery Aerodynamics

The ECOmmodore's striking looks combine form and function. Using computer simulation techniques and making relatively subtle changes to the Commodore shape, Holden engineers targeted a drag co-efficient of 0.28. (Holden don't tell us whether they met the target! - Editor) Changes to the Commodore's shape include a lowered roof, which decreases the vehicle's frontal area. The rear was modified by using sharper edges to better control airflow separation and minimise wake size. The underbody - a major source of aerodynamic drag - is lowered and flat; exhaust systems and brake lines are contained in channels above the floor. Ride height is also lowered, minimising overall drag by reducing the amount of air passing beneath the vehicle.

Rolling Resistance

To reduce the four per cent of total fuel consumption normally lost to rolling resistance, the ECOmmodore sits on 18-inch, lightweight alloy wheels and narrow, low-profile tyres featuring a special low rolling resistance compound and tread pattern. This combination also reduces the frontal area of the tyres and improves the drag coefficient.

Performance Efficiency

The parallel hybrid technology used in the ECOmmodore - where a 50kW electric motor and a lightweight 95kW petrol engine share the drive load - is not new. What makes this hybrid powertrain unique (also low-cost, practical and powerfully effective) is a creative combination of CSIRO-developed supercapacitors, which absorb energy and can deliver it to the electric motor very quickly; long-lasting lead acid batteries and advanced electronic control systems.

When the ECOmmodore is accelerating, petrol and electric engines combine to deliver the necessary surge of power. When it is cruising, or idling, the petrol engine switches off and the electric motor alone takes over.

Features of the compact 2.0 litre Holden engine include an all-aluminium block, spun cast iron alloy liners, floating piston pins for reduced friction and an electric water pump. Accessory loads - air conditioning, compressor, alternator, etc - have been deleted. Recently developed lubricants are used for engine and drive systems.

Regenerative Braking

The ECOmmodore further reduces energy wastage via a regenerative braking system which converts the kinetic energy normally lost in braking into electric energy, which is stored in its supercapacitors and batteries for later use.

Solar Cooling

The use of solar energy for cabin cooling also minimises fuel consumption by reducing the load on ECOmmodore's air conditioning system. Energy generated by a solar panel bonded to its roof drives a fan which continually pumps fresh air into the car, even when it is parked, replacing warm air with ambient temperature air.

Features:

Powertrain

• 95kW, 2.0 litre Family II 4 cylinder engine
• 5 speed Getrag manual transmission
• 45 litre fuel tank
• 50 kW CSIRO electric motor/generator
• 5 CSIRO Double Impact lead acid batteries for main power storage
• CSIRO supercapacitors

Mechanical

• Rack and pinion steering with electro-hydraulic assist
• Independent rear suspension
• Four wheel power disc brakes
• Electrically operated park brake
• Engine hood gas strut assist
• On board computer coordination of electrics, with self-diagnosis

Wheels

• 18 x 5, 5-spoke alloy wheels
• 165/55 low rolling resistance tyres

Driver

• Driver selected modes - hybrid, electrical or petrol
• Four spoke soft feel steering wheel
• Steering wheel height and reach adjust, with electrically operated clamping
• Trip computer
• Satellite Navigation (GPS)
• Battery charge level gauge

Entertainment System

• AM/FM stereo electronic tune radio
• Compact Disc player
• Digital Video Disc (DVD) player
• Television tuner
• Rear video screens

Specifications:

Petrol Engine	Alloy cylinder head and block. Twin camshafts operate four valves per cylinder. Direct (distributorless) ignition controlled by engine management system. Sequential multipoint fuel injection. Selective knock control. 4 cylinders in line Simtec 56.5 engine management
Bore X Stroke (mm)	86.0 x 86.0
Capacity (cc)	1998
Compression Ratio (:1)	9.6
Recommended Petrol Octane	91 (ULP) ALTERNATIVE: 95 (PULP)
Power Output (Kw)	95 (petrol engine only)
Torque (Nm)	185 @ 4000rpm (petrol engine only)
Electric Motor	CSIRO Switched reluctance, 2 separate motors for batteries and supercapacitors
Power (KW)	50 (electric motor only)
Torque (Nm)	105 @ 0-4000rpm (electric motor only)
Petrol/Electric Combined
Power (kW)	145
Torque (Nm)	290 @ 4000rpm