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2010 emission standards

The U.S. Environmental Protection Agency regulates four major pollutants for heavy-duty applications and has set standards that heavy-duty vehicles and transit buses must comply with by 2010. The regulations state that NOx must be 0.2 grams/brake-horsepower hour (g/bhp-hr), PM must be 0.01 g/bhp-hr, nmHC must be 0.14 g/bhp-hr, and CO must be 15.5 g/bhp-hr.

aftertreatment devices

Devices that remove pollutants from exhaust gases after the gas leaves the combustion chamber (e.g., catalytic converters or diesel particulate filters). Some in the emission control industry considers the term "exhaust gas aftertreatment" derogatory, but there is no consensus on the use of such alternatives as post-combustion treatment or exhaust emission control.

alternative fuels

Any method of powering an engine that does not involve petroleum (oil). Some alternative fuels are natural gas, propane, hydrogen, hydrogen-blended natural gas, and electricity.


California Air Resources Board; formed to attain and maintain healthy air quality, conduct research into the causes of and solutions to air pollution, and systematically attack the serious problem caused by motor vehicles. It sets and enforces emission standards for motor vehicles, fuels, and consumer products, as well as health-based air quality standards.


compression ignition; the form of ignition that initiates combustion in a diesel engine. The rapid compression of air within the cylinders generates the heat that is required to ignite the fuel as it is injected.


compressed natural gas; natural gas that has been condensed under high pressures, typically between 3,000 and 3,600 pounds per square inch (PSI), and is held in a container. The gas expands when released for use as a fuel.


compressed natural gas direct injection


carbon monoxide; a colourless and odourless gas that is formed when carbon-containing fuels (i.e., almost any fuel except pure hydrogen) are burned incompletely. In the atmosphere, it elevates concentrations of methane and ozone. In the body, CO reduces oxygen delivery to the organs and tissues.


carbon dioxide; another product of combustion, CO2 does not directly impair human health, but it is the most significant greenhouse gas that contributes to global warming.

commercialization / commercialization agreement

The process of taking a new and proprietary technology to the marketplace. In addition to designing, developing, testing, and marketing the technology, the commercialization process also comprises protecting the intellectual property (IP) rights associated with technology. This IP can include patents, trade secrets, trademarks, goodwill, copyrights, trademarks, industrial designs, and know-how.


Cummins Westport Inc.; the joint venture between Westport and Cummins that began in March 2001. More information at www.cumminswestport.com.


A type of fuel that is a mixture of heavier hydrocarbons from the refining of petroleum. A typical hydrogen to carbon ratio is 1.7 to 1.

diesel cycle

The combustion process of a type of internal combustion engine. In the diesel cycle, only air is drawn into the engine and compressed. The fuel is then injected directly into the cylinder with a high-pressure fuel injector when the piston reaches the top of its motion.

diesel engine

An engine where fuel and combustion air are kept separate until the time of ignition. Typically, a diesel engine injects diesel fuel into its combustion chamber after the air has been highly compressed. The heat caused by compression immediately ignites the fuel. Diesel engines are much more energy efficient than gasoline engines, typically are more durable, and have the ability to do work at very low speeds.


diesel particulate matter; sub-micron size particles found in diesel exhaust. Most emission regulations specify DPM measurement methods in which particulates are sampled on filters from cooled exhaust gas. The cooling causes condensation of vapours in the gas sampling train. Thus, the DPM is composed of both solid and liquid particles and is generally classified into three fractions:

  1. inorganic carbon (soot),
  2. organic fraction (often referred to as SOF or VOF), and
  3. sulphate fraction (hydrated sulphuric acid).


exhaust gas recirculation; EGR systems are used to reduce the amount of nitrogen oxide (NOx) created by the engine. It does this by diluting the air/fuel mixture with a small amount of inert gas (usually less than 10% of the total mixture); exhaust gas is used since it contains only a small amount of oxygen and is readily available. It has the effect of lowering the combustion temperature below the point at which nitrogen combines with oxygen to form NOx.


United States Environmental Protection Agency; the EPA is responsible for researching and setting national standards for environmental programs, and delegates the responsibility for issuing permits and for monitoring and enforcing compliance. Where national standards are not met, EPA can issue sanctions and take other steps to assist in reaching the desired levels of environmental quality.

Euro III / Euro IV / Euro V / Euro VI

Emission standards for heavy-duty diesel engines in the European Union.

fuel cell

An electrochemical cell in which the energy of a reaction between a fuel, such as hydrogen, and an oxidant, such as oxygen, is converted directly and continuously into electrical energy.


gas conditioning module


hydrogen direct injection; the technology that Westport developed with Ford Motor Company and BMW AG.


hydrogen internal combustion engine; an engine that is based on the design of a gasoline engine; however, the primary modifications to the engine involve the injection of hydrogen as a fuel as opposed to gasoline.


hydrogen-blended compressed natural gas.


heavy-duty; refers to markets such as class 8 trucks and buses.

horsepower (hp)

A measurement of the power of engines.


high-pressure direct injection; a patented technology commercialized by Westport for injection of gaseous fuels into engines using the diesel cycle. High pressure means roughly 3,000-5,000 PSI at injection. Injection is direct into the combustion chamber, generally through a single replacement fuel injector.


hot surface ignition; an engine technology where ignition generally depends on a continuously operating glow plug (the hot surface).

hybrid car / hybrid electric vehicle

A vehicle which relies not only on batteries but also on an internal combustion engine, which drives a generator to provide the electricity and may also drive the wheels directly.


At standard temperature and pressure, it is a colourless, odourless, non-metallic, highly flammable gas. Hydrogen is the lightest and most abundant element in the universe, and able to react chemically with most other elements. It is used as an alternative fuel and as a power-source for fuel cells.


integrated gas (accumulator) module


joint venture

Kyoto Protocol

The Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), an international treaty on global warming. It also reaffirms sections of the UNFCCC. Countries which ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases. A total of 141 countries, including Canada and China, have ratified the agreement. Notable exceptions include the United States and Australia. More information at unfccc.int.


lean-burn spark ignited (engine); a type of spark-ignited engine having lower emissions, greater power density, and greater fuel efficiency due to its inherently lower engine knock tendency and higher compression ratio.



life-cycle costs

the total cost to purchase, operate, and maintain a vehicle over the course of ownership. Includes factors like fuel consumption, oil changes, financing charges, resale value, and fuel infrastructure.


liquefied natural gas; natural gas can be cooled until it becomes liquid and then be stored in tanks. This reduces the volume by about 600 times. For transportation between locations where other means of transportation (such as pipelines) is uneconomic, natural gas can be transported by ship as LNG.


memorandum of understanding; an agreement between two (or more) legal entities.


natural gas


natural gas vehicle(s)


non-methane hydrocarbons; the sum of all hydrocarbon air pollutants except methane. nmHCs are significant precursors to ozone formation.


nitrogen oxides; the term used to describe the sum of nitric oxide (NO), nitrogen dioxide (NO2) and other oxides of nitrogen, which play a major role in the formation of ozone, particulate matter, haze, and acid rain. Diesel engines are one of the primary sources of transportation-based NOx.


ozone; a colourless, toxic gas and strong oxidizing agent that can be produced by electric discharge in oxygen or by the action of ultraviolet (UV) radiation on oxygen in the stratosphere (where it acts as a screen for UV radiation).


Organisation for Economic Co-operation and Development; a forum where the governments of 30 market democracies work together to address the economic, social, environmental, and governance challenges of the globalising world economy, as well as to exploit its opportunities.


original equipment manufacturer; a company that purchases complex components from manufacturers, adds other hardware, and sells the systems, often for specific applications.


particulate matter; a mixture of solid particles and liquid droplets found in the air. It originates from a variety of sources, including motor vehicles, power plants, construction activities, soil dust, soot, and industrial processes.


spark ignited (natural gas engines); medium- and heavy-duty engines that incorporate spark plugs to ignite the fuel. Cummins Westport's product line consists entirely of SI engines.


sulphur dioxide; a gas that is formed when fuel containing sulphur (mainly coal and oil) is burned. SO2 is responsible for several health issues, as well as being a precursor to acid rain.

technology development agreement

an agreement to apply one's technology on a partner's engine or vehicle for the purpose of demonstrating performance and emissions capability. It usually precedes a commercialization agreement.


total hydrocarbons; the sum of all hydrocarbons, including methane.


that which tends to change the rate of rotation of a body; also called the moment of force. The torque produced by rotating parts of an electric motor or internal-combustion engine is often used as a measure of its ability to do useful work. The magnitude of the torque acting on a body is equal to the product of the force acting on the body, and the distance from its point of application to the axis around which the body is free to rotate.


World Health Organization; a United Nations agency mandated to coordinate international health activities and to help governments improve health services.