diesel exhaust systems
A word from the DTF
A Word from the DTF
www.dieselforum.org -- Diesel engines are cleaner than ever before, and in the next few years the diesel industry will
virtually eliminate key emissions associated with on- and off-road diesel equipment. This environmental progress is the
result of the new clean diesel system - combining clean diesel fuel, advanced engines and effective exhaust-control
Diesel is a petroleum-based fuel with a high energy content - helping diesel go further per gallon than most other
Diesel is the world's most efficient internal combustion engine. It provides more power and more fuel efficiency than
alternatives such as gasoline, compressed natural gas or liquefied natural gas. Read more about the history of the diesel
Fuel combustion is the primary difference between gasoline and diesel engines. Gasoline engines ignite fuel with spark
plugs, whereas diesels ignite fuel with compression. The piston stroke in a diesel engine results in a compression of the
fuel air mixture so intense that it combusts spontaneously.
Advanced new technologies such as electronic controls, common rail fuel injection, variable injection timing, improved
combustion chamber configuration and turbocharging have made diesel engines cleaner, quieter and more powerful than past
With the introduction of lower sulfur diesel fuel, a number of exhaust treatment systems can further reduce emissions from
Particulate Traps - collect particulate matter as the exhaust gases pass through and can reduce particulate emissions by
80-90 percent using a catalytic reaction or an auxiliary heating element.
Catalytic Converters - use a chemical reaction to convert emissions into harmless substances. Some catalysts - such as
selective catalytic reduction (SCR) devices and NOx absorbers - focus on nitrogen oxides and can reduce these emissions by
Clean diesel engines offer any environmental advantages over other types of engines?
Clean diesel engines emit lower levels of certain emissions compared to gasoline engines. Diesel emits only small amounts of
carbon monoxide, hydrocarbons and carbon dioxide. In addition, the fuel efficiency of diesel engines means they burn
considerably less fossil fuel and produce fewer greenhouse gas emissions.
How are modern clean diesel systems different from the engines of 10 years ago?
The industry has made significant strides in recent years to develop diesel systems that are cleaner and more efficient than
ever before. Thanks to state-of-the-art engines, cleaner-burning fuels, effective emissions-control systems, and
advancements in the fuel injection system, it would take 60 trucks sold today to equal the soot emissions of one 1988 truck.
Data from the U.S. Environmental Protection Agency (EPA) shows that the level of diesel particulates in the air fell by more
than 37 percent during the 1990s.
Is it normal for diesel engines to emit black smoke?
No. New clean diesel engines do not smoke and have been designed to be smoke free
since 1994. When a diesel engine emits excessive smoke, it means that it is out of tune, in need of maintenance or not operating efficiently. Black smoke is caused
by unburned fuel and indicates wasted energy and money for the operator. It is in the owner's interest to take corrective