A

Aldehydes

A class of organic compounds derived by removing the hydrogen atoms from an alcohol. Aldehydes can be produced from the oxidation of an alcohol.

 

Alternative Fuel

Methanol, denatured ethanol, and other alcohols; mixtures containing 85% or more by volume of methanol, denatured ethanol, and other alcohols with gasoline or other fuels; natural gas; liquefied petroleum gas; hydrogen; coal-derived liquid fuels; non-alcohol fuels (such as biodiesel) derived from biological material; and electricity. 'P-Series' fuels were added to this list since the original definition in EPAct.

 

Alternative Fuel Vehicle (AFV)

As defined by the Energy Policy Act, any dedicated, flexible-fuel, or dual-fuel vehicle designed to operate on at least one alternative fuel.

 

Alternative Fuels Data Center (AFDC)

A program sponsored by DOE and managed by the National Renewable Energy Laboratory to collect data and information on all types of Alternative Fuels and AFVs across the country.

 

Alternative Fuels Utilization Program (AFUP)

A program managed by DOE with the goals of improving national energy security by displacing imported oil, improving air quality by development and widespread use of alternative fuels for transportation and increasing the production of AFVs.

 

Alternative Motor Fuels Act of 1988 (AMFA)

Public Law 100-494. Encourages the development, production and demonstration of alternative motor fuels and AFVs.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

Alternative-Fuel Provider

A fuel provider (or any affiliate or business unit under its control) is an alternative fuel provider if its principal business is producing, storing, refining, processing, transporting, distributing, importing or selling (at wholesale or retail) any alternative fuel (other than electricity); or generating, transmitting, importing, or selling (at wholesale and retail) electricity; or if that fuel provider produces, imports, or produces and imports (in combination), an average of 50,000 barrels per day of petroleum and 30% (a substantial portion) or more of its gross annual revenues are derived from producing alternative fuels.

 

American Society for Testing and Materials (ASTM)

A non-profit organization that provides a management system to develop published technical information. ASTM standards, test methods, specifications and procedures are recognized as definitive guidelines for motor fuel quality as well as a broad range of other products and procedures.

 

Anhydrous

Describes a compound that does not contain any water. Ethanol produced for fuel use is often referred to as anhydrous ethanol, as it has had almost all water removed.

 

Aromatics

Hydrocarbons based on the ringed six-carbon benzene series or related organic groups. Benzene, Toluene and Xylene are the principal aromatics, commonly referred to as the BTX group. They represent one of the heaviest fractions in gasoline.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B

B100

100% (neat) biodiesel.

 

B20

A blend of biodiesel fuel with petroleum-based diesel where 20% is the volume is biodiesel.

 

BTX

Industry term referring to the group of aromatic hydrocarbons benzene, toluene and xylene (see aromatics).

 

Balance of Payments

The dollar amount difference between a country's exports and imports. In the United States, large oil imports are one of the main causes of the negative balance of payments with the rest of the world.

Benzene

A six-carbon aromatic; common gasoline component identified as being toxic. Benzene is a known carcinogen.

 

Bi-Fuel Vehicle

A vehicle with two separate fuel systems designed to run on either an alternative fuel, or gasoline or diesel, using only one fuel at a time. Bi-fuel vehicles are referred to as "dual-fuel" vehicles in the Clean Air Act Amendments and Energy Policy Act.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B

Biochemical Conversion

The use of enzymes and catalysts to change biological substances chemically to produce energy products. For example, the digestion of organic wastes or sewage by microorganisms to produce methane is a biochemical process.

 

Biodiesel

A biodegradable transportation fuel for use in diesel engines that is produced through transesterification of organically derived oils or fats. Biodiesel is used as a component of diesel fuel. In the future it may be used as a replacement for diesel.

 

Biomass

Renewable organic matter such as agricultural crops, crop-waste residues, wood, animal and municipal waste, aquatic plants; fungal growth, etc., used for the production of energy.

 

British Thermal Unit (Btu)

A standard unit for measuring heat energy. One Btu represents the amount of heat required to raise one pound of water one degree Fahrenheit (at sea level).

Butane

A gas, easily liquefied, recovered from natural gas. Used as a low-volatility component of motor gasoline, processed further for a high-octane gasoline component, used in LPG for domestic and industrial applications and used as a raw material for petrochemical synthesis.

 

Butyl Alcohol

Alcohol derived from butane that is used in organic synthesis and as a solvent.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

California Air Resources Board (CARB)

The state agency that regulates the air quality in California. CARB standards are often stricter than federal standards.

 

Carbon Dioxide (CO2)

A product of combustion that has become an environmental concern in recent years. CO2 does not directly impair human health but is a greenhouse gas that traps the earth's heat and contributes to the potential for global warming.

 

Carbon Monoxide (CO)

A colorless, odorless gas produced by the incomplete combustion of fuels with a limited oxygen supply, as in automobile engines.

 

Carbon Sequestration

The absorption and storage of CO2 from the atmosphere by the roots and leaves of plants; the carbon builds up as organic matter in the soil.

 

Carcinogens

Chemicals and other substances known to cause cancer.

 

Catalyst

A substance whose presence changes the rate of chemical reaction without itself undergoing permanent change in its composition. Catalysts may be accelerators or retarders. Most inorganic catalysts are powdered metals and metal oxides, chiefly used in the petroleum, vehicle and heavy chemical industries.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

Cellulosic Ethanol

Ethanol made from trees, grasses and crop waste is called cellulosic ethanol.

 

Cetane

Ignition performance rating of diesel fuel. Diesel equivalent to gasoline octane.

 

Clean Air Act (CAA)

Signed into law in 1963, then amended in 1970, and again in 1990 (see Clean Air Act Amendments of 1990). Includes emissions standard for mobile and stationary sources. Enforced by the U.S. Environmental Protection Agency.

 

Clean Air Act Amendments of 1990 (CAAA)

Amendments to the Clean Air Act of 1970. The Clean Air Act Amendments of 1990 created two new gasoline standards designed to reduce harmful fuel emissions for vehicles in highly polluted cities. The Act required gasoline to contain cleaner-burning additives called fuel oxygenates such as ethanol. This Act recognized that changes in motor fuels and fuel composition would play a vital role in reducing pollution from motor vehicle exhaust.

 

Clean Cities Program

A voluntary program established and administered by DOE to increase AFV market penetration, particularly in more polluted urban areas. Clean Cities chapters are recognized by DOE as having successfully established a self-sustaining environment for AFVs. Specific chapters may include federal, state, and local government agencies, vehicle manufacturers and suppliers, fleet managers, utilities, local distribution companies, and other stakeholders. The first international entities joined the program in 1995.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

Clean Fuel Fleet Program

Implemented by the Environmental Protection Agency as a provision of the Clean Air Act Amendments of 1990 to require cities with significant air quality problems to incorporate vehicles that will meet clean fuel emissions standards.

 

Compressed Natural Gas (CNG)

Natural gas that has been compressed under high pressures, typically 2000 to 3600 psi, held in a container. The gas expands when used as a fuel.

 

Compression Ignition

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

Dedicated Natural Gas Vehicle

A vehicle that operates only on natural gas. Such a vehicle is incapable of running on any other fuel.

 

Dedicated Vehicle

A vehicle that operates solely on one fuel. Generally, dedicated vehicles have superior emissions and performance results because their design has been optimized for operation on a single fuel.

 

Dedicated Vehicle

A vehicle that operates solely on one fuel. Generally, dedicated vehicles have superior emissions and performance results because their design has been optimized for operation on a single fuel.

 

Department of Energy

See U.S. Department of Energy (DOE).

 

Detergent

Additives used to inhibit deposit formation in the fuel and intake systems in automobiles.

 

Dimethyl Ether (DME)

An oxygenated hydrocarbon, which is the simplest compound in the class of ethers. It is generally produced from natural gas but almost any carbon-based feedstock can be used, including crude oil, coal, crop residues, oil sands, wood, or straw.

 

Distillation Curve

The percentages of gasoline that evaporate at various temperatures. The distillation curve is an important indicator for fuel standards such as volatility (vaporization).

 

Domestic Fuel

As defined by the Energy Policy Act, Section 301,domestic fuel is derived from resources within the United States, its possessions and commonwealths, and Canada and Mexico (the two nations in a free-trade agreement with the U.S.).

 

Dynamometer

An instrument for measuring mechanical force, or an apparatus for measuring mechanical power (as of an engine).

 

 

 

 

 

 

 

 

E

E10 (Gasohol)

Ethanol mixture containing 10% ethanol, 90% unleaded gasoline.

 

E85

Ethanol/gasoline mixture containing 85% denatured ethanol and 15% gasoline, by volume.

 

Electric Vehicle

A vehicle powered by electricity, generally provided by batteries. EVs qualify in the zero emission vehicle (ZEV) category for emissions.

 

Electricity

Electric current used as a power source. Electricity can be generated from a variety of feedstocks including oil, coal, nuclear, hydro, natural gas, wind, and solar. In electric vehicles, onboard rechargeable batteries power an electric motor.

 

Emission Standards

Limits or ranges established for pollution levels emitted by vehicles as well as stationary sources. The first standards were established under the 1963 Clean Air Act. Emissions limits are imposed on four classes of vehicles; automobiles, light-duty trucks, heavy-duty gasoline trucks, and heavy-duty diesel trucks.

 

Energy Policy Act of 1992 (EPAct)

Passed by Congress to enhance U.S. energy security by reducing our dependence on imported oil by mandating the use of alternative fuel vehicles, beginning with federal, then state, then fuel provider fleets.

 

Energy/Fuel Diversity

A policy that encourages the development of energy technologies to diversify energy supply sources, thus reducing reliance on conventional (petroleum) fuels; energy/fuel diversity applies to all energy sectors.

 

Energy/Fuel Security

A policy that considers the risk of dependence on fuel sources located in remote and unstable regions of the world. It also considers the benefits of domestic and diverse fuel sources.

 

Environmental Protection Agency

See U.S. Environmental Protection Agency (EPA)

 

 

 

 

 

 

 

E

Ester

An organic compound formed by reacting an acid with an alcohol, always resulting in the elimination of water.

Ethanol (also known as Ethyl Alcohol, Grain Alcohol, CH 3 CH 2 OH)

Can be produced chemically from ethylene or biologically from the fermentation of various sugars from carbohydrates found in agricultural crops and cellulosic residues from crops or wood. Used in the United States as a gasoline octane enhancer and oxygenate, it increases octane 2.5 to 3.0 numbers at 10% concentration. Ethanol also can be used in higher concentration in alternative fuel vehicles optimized for its use.

 

Ether

A class of organic compounds containing an oxygen atom linked to two organic groups.

 

Ethyl Alcohol

See Ethanol.

 

Ethyl Ester

A fatty ester formed when organically derived oils are combined with ethanol in the presence of a catalyst. After water washing, vacuum drying and filtration, the resulting ethyl ester has characteristics similar to petroleum-based diesel motor fuels.

 

Ethyl Tertiary Butyl Ether (ETBE)

A fuel oxygenate used as a gasoline additive to increase octane and reduce engine knock.

 

Evaporative Emissions

Hydrocarbon vapors that escape from a fuel storage tank or a vehicle fuel tank or vehicle fuel system.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

F

Feedstock

Any material converted to another form of fuel or energy product. For example, cornstarch can be used as a feedstock for ethanol production.

 

Fermentation

The enzymatic transformation by microorganisms of organic compounds, such as sugar. It is usually accompanied by the evolution of gas as the fermentation of glucose into ethanol and CO2.

 

Fischer-Tropsch

A method, discovered in 1923 by the German coal researchers Franz Fischer and Hans Tropsch, for the synthesis of hydrocarbons and other aliphatic compounds. A mixture of hydrogen and carbon monoxide is reacted in the presence of an iron or cobalt catalyst. Much heat is evolved and products such as methane, synthetic gasoline and waxes, and alcohols are made. Water or carbon dioxide is its by-product.

 

Flex Fuel

See E85.

 

Flexible-Fuel Vehicle

Vehicles with a common fuel tank designed to run on varying blends of unleaded gasoline with either ethanol or methanol.

 

Fossil Fuel

Fuels such as coal, oil, and natural gas. They are called fossil fuels because they are the remains of ancient plant and animal life.

 

Fuel Cell

An electrochemical engine with no moving parts that converts the chemical energy of a fuel, such as hydrogen, and an oxidant, such as oxygen, directly to electricity. The principal components of a fuel cell are catalytically activated electrodes for the fuel (anode) and the oxidant (cathode) and an electrolyte to conduct ions between the two electrodes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G

Gas to Liquid Technology

Gas-to-liquid conversion technologies use chemical or physical means to convert natural gas to a liquid form suitable for ready transport or direct use.

 

Gasohol

In the United States, gasohol (E10) refers to gasoline that contains 10% ethanol by volume. This term was used in the late 1970s and early 1980s but has been replaced in some areas of the country with E-10, super unleaded plus ethanol, or unleaded plus.

 

Gasoline Gallon Equivalent (gge)

A unit for measuring alternative fuels so that they can be compared with gasoline on an energy equivalent basis. This is required because the different fuels have different energy densities.

 

Global Warming

The theoretical escalation of global temperatures caused by the increase of greenhouse gas emissions in the lower atmosphere.

 

Greenhouse Effect

A warming of the earth and its atmosphere as a result of the thermal trapping of incoming solar radiation by CO2, water vapor, methane, nitrous oxide, chlorofluorocarbons, and other gases, both natural and man-made.

 

Gross Vehicle Weight Rating (GVWR)

Maximum weight of a vehicle, including payload.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

Heavy-Duty Vehicle

Generally, a vehicle that has a GVWR of more than 26,000 lb. Definitions vary by organization.

 

High Occupancy Vehicle (HOV) Lanes

Lanes on the highway that are restricted to vehicles carrying more than one passenger.

 

Hybrid Electric Vehicle

A vehicle powered by two or more energy sources, one of which is electricity. HEVs may combine the engine and fuel of a conventional vehicle with the batteries and electric motor of an electric vehicle in a single drivetrain.

 

Hydrogen

The most abundant element in the universe, it consists of one proton in the nucleus and one electron in one shell. It is the lightest and most simple element. Chevy has launched a test fleet of hydrogen-powered Equinox Fuel Cell SUVs. Hydrogen fuel cells use zero gasoline and produce zero emissions other than water vapor.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I

Infrastructure

Generally refers to the recharging and refueling network necessary to successful development, production, commercialization, and operation of alternative fuel vehicles. It includes fuel supply, public and private recharging and refueling facilities, standard specifications for refueling outlets, customer service, education and training, and building code regulations.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

LNG to CNG Station

A station, supplied with LNG, that pumps and vaporizes the liquid supply to vehicles as CNG fuel, generally at the correct pressure and temperature (i.e., the temperature effect of compression is factored into the design).

 

LNG vehicle

A vehicle that uses LNG as its fuel.

 

Lead

See Tetraethyl Lead.

 

Light Duty Vehicle

Passenger cars and trucks with a gross vehicle weight rating of 8,500 or less.

 

Liquefied Natural Gas (LNG)

Compressed natural gas that is cryogenically stored in its liquid state.

 

Liquefied Petroleum Gas (LPG)

A mixture of hydrocarbons found in natural gas and produced from crude oil, used principally as a feedstock for the chemical industry, home heating fuel, and motor vehicle fuel. Also known by the principal constituent propane.

 

Liter (L)

A metric measurement used to calculate the volume displacement of an engine. One liter is equal to 1,000 cubic centimeters or 61 cubic inches.

 

Low-Emission Vehicle (LEV)

A vehicle that meets EPA's CFV or LEV standards or CARB's California LEV standards.

 

Lubricity

Capacity to reduce friction.

 

 

 

 

 

 

 

 

 

 

 

M

M100

100% (neat) methanol.

 

Medium Duty Vehicle

Typically, a vehicle with a GVWR of 8,500 to 14,000 lb.

 

Methane (CH4)

The simplest of the hydrocarbons and the principal constituent of natural gas. Pure methane has a heating value of 1,012 Btu per stnd. cubic foot.

 

Methanol (also known as Methyl Alcohol, Wood Alcohol, CH3, OH)

A liquid fuel formed by catalytically combining CO with hydrogen in a 1 to 2 ratio under high temperature and pressure. Commercially, it is typically manufactured by steam reforming natural gas. Also formed in the destructive distillation of wood.

 

Methyl Alcohol

See Methanol.

 

Methyl Ester

A fatty ester formed when organically derived oils are combined with methanol in the presence of a catalyst. Methyl Ester has characteristics similar to petroleum-based diesel motor fuels.

 

Methyl Tertiary Butyl Ether (MTBE)

A fuel oxygenate used as an additive to gasoline to increase octane and reduce engine knock.

 

Mobile Source Emissions

Emissions resulting from the operations of any type of motor vehicle.

 

Motor Octane

The octane as tested in a single-cylinder octane test engine at more severe operating conditions. Motor Octane Number (MON) affects high-speed and part-throttle knock and performance under load, passing, climbing and other operating conditions. Motor octane is represented by the designation M in the (R+M)/2 equation and is the lower of the two numbers.

 

 

 

 

 

 

 

 

 

N

Natural Gas

A mixture of gaseous hydrocarbons, primarily methane, occurring naturally in the earth and used principally as a fuel.

 

Natural Gas Distribution System

This term generally applies to mains, services, and equipment that carry or control the supply of natural gas from a point of local supply, up to and including the sales meter.

 

Natural Gas Transmission System

Pipelines installed for the purpose of transmitting natural gas from a source or sources of supply to one or more distribution centers.

 

Natural Gas Vehicle

Vehicles that are powered by compressed or liquefied natural gas.

 

Near Neat Fuel

Fuel that is virtually free from admixture or dilution.

 

Neat Alcohol Fuel

Straight or 100% alcohol (not blended with gasoline), usually in the form of either ethanol or methanol.

 

Neat Fuel

Fuel that is free from a mixture or dilution with other fuels.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N

Non-Attainment Area

A region, determined by population density in accordance with the U.S. Census Bureau, which exceeds minimum acceptable NAAQS for one or more "criteria pollutants" (see Clear Air Act Amendments). Such areas are required to seek modifications to their State Implementation Plans, setting forth a reasonable timetable using EPA-approved means to achieve attainment of NAAQS for these criteria pollutants by a certain date. Under the CAA, if a non-attainment area fails to attain NAAQS, EPA may superimpose a Federal Implementation Plan with stricter requirements or impose fines, constructions bans, cutoffs in federal grant revenues, and so forth, until the area achieves the applicable NAAQS.

 

Non-Methane Organic Gases (NMOG)

The sum of non-oxygenated and oxygenated hydrocarbons (exclusive of methane) contained in a gas sample as measured in accordance with California's non-methane organic gas test procedure.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

OEM

Original Equipment Manufacturer.

 

Octane Enhancer

Any substance such as MTBE, ETBE, toluene andxylene that is added to gasoline to increase octane and reduce engine knock.

 

Octane Rating (Octane Number)

A measure of a fuel's resistance to self ignition, hence a measure as well of the antiknock properties of the fuel.

 

Office of Transportation and Air Quality

Division of EPA that protects public health and the environment by controlling air pollution from motor vehicles, engines, and the fuels used to operate them, and by encouraging travel choices that minimize emissions.

 

Oil Life System

The GM Oil Life System analyzes the engine's operational data including temperature, revolutions and speed, to calculate the rate of engine oil degradation and determine when an oil is nearing the end of its life. At this point a message on the dashboard signals that it is time to change oil.

 

Onboard Refueling Vapor Recovery (ORVR)

System required on vehicles beginning in 1998 to control refueling emissions.

 

Open-Loop Fuel Control

System in which the air/fuel mixture is preset by design with no feedback correction signal to optimize fuel metering.

 

Original Equipment Manufacturer (OEM)

The original manufacturer of a vehicle or engine.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

Oxides of Nitrogen (NOx)

Regulated air pollutants, primarily NO and NO2 but including other substances in minute concentrations. Under the high pressure and temperature conditions in an engine, nitrogen and oxygen atoms in the air react to form various NOx. Like hydrocarbons, NOx are precursors to the formation of smog. They also contribute to the formation of acid rain.

 

Oxygenate

A term used in the petroleum industry to denote fuel additives containing hydrogen, carbon and oxygen in their molecular structure. Includes ethers such as MTBE and ETBE and alcohols such as ethanol and methanol.

 

Oxygenated Fuels

Fuels blended with an additive, usually methyl tertiary butyl ether (MTBE) or ethanol to increase oxygen content, allowing more thorough combustion for reduced carbon monoxide emissions.

 

Oxygenated Gasoline

Gasoline containing an oxygenate such as ethanol or MTBE. The increased oxygen content promotes more complete combustion, thereby reducing tailpipe emissions of CO.

 

Ozone

Tropospheric ozone (smog) is formed when volatile organic compounds (VOCs), oxygen, and NOx react in the presence of sunlight (not to be confused with stratospheric ozone, which is found in the upper atmosphere and protects the earth from the sun's ultraviolet rays). Though beneficial in the upper atmosphere, at ground level ozone is a respiratory irritant and considered a pollutant.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

Paraffins

Group of saturated aliphatic hydrocarbons, including methane, ethane, propane and butane and noted by the suffix "-ane".

 

Particulate Matter (PM)

A generic term for a broad class of chemically and physically diverse substances that exist as discrete particles (liquid droplets or solids) over a wide range of sizes. A NAAQS pollutant.

 

Particulate Trap

Diesel vehicle emission control device that traps and incinerates diesel particulate emissions after they are exhausted from the engine but before they are expelled into the atmosphere.

 

Petroleum Fuel

Gasoline and diesel fuel.

 

Phase Separation

The phenomenon of a separation of a liquid or vapor into two or more physically distinct and mechanically separable portions or layers.

 

Portable Fueling System

A system designed to deliver natural gas to fueling stations. Such systems are usually configured as tube trailers and are mobile. Fuel delivery usually occurs via over-the-road vehicles.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

Pounds Per Square Inch (psi)

A unit of measure for pressure.

 

Private Fleet

A fleet of vehicles owned by a non-government entity.

 

Propane (C3H8)

A gas whose molecules are composed of three carbon and eight hydrogen atoms. Propane is present in most natural gas in the United States, and is also refined from crude petroleum. Propane contains about 2,500 BTUs per standard cubic foot. Propane is the principal constituent in Liquified Petroleum Gas (LPG).

 

Public Fueling Station

Refers to fueling station that is accessible to the general public.

 

Pump Octane

The octane as posted on retail gasoline dispensers as (R+M)/2; same as Antiknock Index.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

Reactivity Adjustment Factor (RAF)

An NMOG adjustment used in the certification of vehicles to the California emission standards to reflect reduced ozone forming potential of a fuel, especially alternative fuels.

 

Reformulated Gasoline (RFG)

Gasolines that have had their compositions and/or characteristics altered to reduce vehicular emissions of pollutants, particularly pursuant to EPA regulations under the CAA.

 

Refueling Emissions

VOC vapors that escape from the vehicle fuel tank during refueling. Storage II pump controls and onboard refueling vapor recovery systems (ORVR) are intended to control these emissions.

 

Reid Vapor Pressure (RVP)

A standard measurement of a liquid's vapor pressure in psi at 100°F. It is an indication of the propensity of the liquid to evaporate.

 

Research Octane Number (RON)

The octane as tested in a single-cylinder octane test engine operated under less severe operating conditions. RON affects low to medium-speed knock and engine run-on. Research Octane is presented by the designation R in the (R+M)/2 equation and is the higher of the two numbers.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S

Smog

A visible haze caused primarily by particulate matter and ozone. Ozone is formed by the reaction of hydrocarbons and NOx in the atmosphere.

 

Spark Ignition Engine

Internal combustion engine in which the charge is ignited electrically (e.g., with a spark plug).

 

Stakeholders

Citizens, environmentalists, businesses, and government representatives that are served by the air quality management system.

 

State Energy Program

Program offered by the U.S. Department of Energy that allows states to compete for funding to implement activities related to programmatic areas, such as federal energy management, building codes and standards, alternative fuels, industrial efficiency, building efficiency, and renewable energy technologies.

 

State Implementation Plan (SIP)

Plan that a state must submit to EPA under the CAA to demonstrate compliance to NAAQS.

 

Sulfur Dioxide (SO2)

An EPA criteria pollutant.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

Tailpipe Emissions

EPA-regulated vehicle exhaust emissions released through the vehicle tailpipe. Tailpipe emissions do not include evaporative and refueling emissions, which are also regulated by EPA. EPA publishes allowable emission levels and vehicle certification standards in the Code of Federal Regulations.

 

Tax Incentives

In general, a means of employing the tax code to stimulate investment in or development of a socially desirable economic objective without direct expenditure from the budget of a given unit of government. Such incentives can take the form of tax exemptions or credits.

 

Tertiary Amyl Ethyl Ether (TAEE)

An ether based on reactive C5 olefins and ethanol.

 

Tertiary Amyl Methyl Ether (TAME)

An ether based on reactive C5 olefins and methanol.

 

Tetraethyl Lead or Lead

An octane enhancer. One gram of lead increases the octane of one gallon of gasoline about 6 numbers. The EPA has phased down the use of lead in gasoline as it has been determined to be a health hazard. Lead has been prohibited in highway vehicle gasoline since January 1, 1996.

 

Therm

A unit of heating value equivalent to 100,000 British Thermal Units (BTUs).

 

Toluene

Basic aromatic compound derived from petroleum and used to increase octane. The most common hydrocarbon purchased for use in increasing octane.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

Toxic Emission

Any pollutant emitted from a source that can negatively affect human health or the environment.

 

Toxic Substance

A generic term referring to a harmful substance or group of substances. Typically, these substances are especially harmful to health, such as those considered under EPA's hazardous substance program. Technically, any compound that has the potential to produce adverse health effects is considered a toxic substance.

 

Transesterification

A process in which organically-derived oils or fats are combined with alcohol (ethanol or methanol) in the presence of a catalyst to form esters (ethyl or methyl ester).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U

U.S. Department of Energy (DOE)

A department of the federal government, established by the Carter Administration in 1977, to consolidate energy-oriented programs and agencies. The DOE mission includes the coordination and management of energy conservation, supply, information dissemination, regulation, research, development and demonstration. The Department includes the Office of Transportation Technologies.

 

U.S. Environmental Protection Agency (EPA)

A government agency, established in 1970, responsible for protecting the environment and public health. EPA seeks to reduce air, water, and land pollution and pollution from solid waste, radiation, pesticides and toxic substances. EPA also controls emissions from motor vehicles, fuels, and fuel additives.

 

U.S. Department of Transportation

A government agency whose mission is to ensure a fast, safe, efficient, accessible, and convenient transportation system that meets the national interests and enhances our quality of life.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V

Vapor Pressure or Volatility

The tendency of a liquid to pass into the vapor state at a given temperature. With automotive fuels, volatility is determined by measuring RVP.

 

Variable Fuel Vehicle (VFV)

A vehicle that has the capacity of burning any combination of gasoline and an alternative fuel. Also known as a flexible fuel vehicle.

 

Variable Valve Timing

Several of GM's most popular engines feature VVT, and GM was the first manufacturer to mass produce cam-in-block engines with VVT. By adjusting the timing of the intake and exhaust valves, variable valve timing:

 

• - Optimizes combustion for performance and economy

• - Helps optimize emission performance

• - Enhances the existing outstanding balance of power, efficiency, low emissions and NVH (noise, vibration, handling) engineered into the engine

 

Vehicle Miles Traveled

The miles traveled by motor vehicles over a specified length of time (e.g. daily, monthly, or yearly) or over a specified road or transportation corridor.

 

Volatile Organic Compound (VOC)

Reactive gas released during combustion or evaporation of fuel and regulated by EPA. VOCs react with NOx in the presence of sunlight and form ozone.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

X

Xylene

An aromatic hydrocarbon derived from petroleum and used to increase octane. Highly valued as a petrochemical feedstock. Xylene is highly photochemically reactive and, as a constituent of tailpipe emissions, is a contributor to smog formation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Z

Zero Emission Vehicle (ZEV)

A vehicle that emits no tailpipe exhaust emissions. ZEV credits can be banked within the Consolidated Metropolitan Statistical Area.