Autofarm: Low Pollution Alternate Fuel Vehicles

Isuzu is developing low-pollution vehicles using alternative energy sources or hybrid systems to reduce emissions. Such vehicles are not only a vital step toward achieving lower emissions of pollutants, they will also contribute to the more effective utilization of limited resources.

Compressed Natural Gas (CNG) Vehicles

The CNG-powered engines emit very low NOx carbon monoxide (CO) and hydrocarbons (HC) and virtually no particulate matter (PM) at all. Another characteristic of natural gas, of which the main constituent gas is methane, is that it produces very little CO

. Isuzu produces three-way catalytic converter-equipped CNG vehicles that achieve an excellent low-pollution emission performance.

CNG (Compressed Natural Gas) is available from the significant reserves of natural gas that exist in many places around the world. Unlike in the case of petroleum, the bulk of supplies are not concentrated in the Middle East and reserves of natural gas are considered to be much larger than those of petroleum. Accordingly, this fuel has an important role in maintaining a stable supply of energy.

ELF CNG-MPI (Multi Point Injection)

[Advantages]

Zero PM emission

Low NOx emission

Very low CO

emission

[Disadvantages]

Short running distance

Heavy fuel container

Dimethyl Ethel Engine (DME) Vehicles

With various advantages, The DME engine is getting wide recognition as a next generation, alternative-fuel powerplant. DME emits no black smoke and very little PM and Nox.

Dimethyl Ether is made from charcoal and natural gas. It is very stable fuel which can be liquified under normal temperatures at low atmosperic pressure. Easy transportation and storage is also its advantage.

[Advantages]

	Zero PM emission and black smoke
	Very low Nox emission
	Good fuel economy equivalent to diesel engine
	Easy handling

[Disadvantages]

	Shorter running distance than diesel engine
	Unsufficient Infrastracture

Diesel Hybrid Vehicles

Hybrid vehicles are designed to realize low pollution and energy saving by dual power sources. Isuzu's Elf diesel hybrid achieves low-CO

emission levels and high fuel efficiency by fully extracting energy available when the vehicle decelerates. It uses diesel for fuel, needs no special infrastructure, and can be serviced anywhere. In addition, the Elf Diesel hybrid truck employs Isuzu's original hybrid system, which was optimized for light-duty trucks. The system achieves excellent fuel economy compared to other hybrid vehicles, and delivers the high durability and safety performance required by commercial vehicles at the same time.
The Elf diesel hybrid truck has the following features:

•	The hybrid system is based on the 4HL1 diesel engine. In addition to assisting the engine by adding an electric motor, the Smoother-E automatic shift system allows high-efficiency regenerative energy and automatic shifting in fuel-saving speed ranges.
•	For the first time on a domestic truck, a Lithium-ion battery is used that provides approximately 3 times longer life than a nickel metal hydride battery.
•	A PTO-type parallel drive hybrid system is employed, so that even if a failure occurs in the hybrid system, the motor and generator being installed on a shaft different from that of the engine, driving can be continued on just the diesel engine, without interference to the engine driveline.

ELF Diesel Hybrid

[Advantages]

	Improved fuel consumption resulting in lower CO emissions
	Reduced exhaust emissions during start up and acceleration

[Disadvantages]

Complex systems and high maintenance costs

When starting and accelerating, or when the engine is under a heavy load, the vehicle runs on both the engine and electric motor using battery power

Vehicle runs as a fuel-efficient diesel engine during constant-speed runs only. The Smoother-E automatic shift changes speeds automatically for optimum fuel economy.

When decelerating, Smoother-E automatic shift automatically disengages clutch to prevent loss of regenerative energy, charging on battery efficiently.

After stopping, moving the shift lever into the N position will stop the engine automatically. Moving the lever to D restarts the engine. Gas emission is reduced, while fuel economy is improved at the same time.

Fuel Cell Vehicles

Fuel cell vehicles are highly advanced low-pollution vehicles that generate electricity through a chemical reaction between hydrogen and oxygen and use this electricity to drive a motor. R&D is currently proceeding into a system for storing hydrogen in a special alloy and a system utilizing methanol. Fuel cells are highly fuel-efficient, so they are considered as the next-generation of vehicle powerplants.