Responsible Purchasing Network

Fleets: Definitions

This glossary includes key terms from the Guide and may be used as a companion to the text.


Acid rain
acidic compounds caused by pollutants such as sulfur dioxide (SO2) and nitrogen oxides (Nox) that collect in the atmosphere, are absorbed by clouds, and create acidic rainfall
Advanced hybrid
a hybrid-electric vehicle (HEV) that uses advanced energy recovery technologies (e.g., regenerative braking) and is capable of driving in all-electric mode, see also hybrid-electric vehicle and hollow hybrid
biofuel composed of 20% biodiesel and 80% gasoline, see also biodiesel
basic information gathered before a program begins that is used later to provide a comparison for assessing program impact
products composed in whole or in significant part of biological products, forestry materials, or renewable domestic agricultural materials, including plant, animal, or marine materials, generally safer for the environment than petroleum-based counterparts, and usually biodegradable or recyclable.
a substitute for petroleum based diesel fuel that is produced from agricultural crops such as soybeans 
a system providing simple, regular access to vehicles without personal ownership; typically run by a for-profit company such as FlexCar and ZipCar
Cellulosic ethanol
a high-energy yielding ethanol fuel produced from cellulose, a naturally occuring carbohydrate commonly found in plant cell walls; cellulosic ethanol has a better lifecycle energy and emissions profile than corn ethanol but is currently more expensive to produce. See also "ethanol" 
compressed natural gas; used as vehicle fuel, see also "NGV"
vehicle fuel type composed of 85% ethanol and 15% gasoline, see also "ethanol" and "flex-fuel"
Environmentally preferable
products and services that have a lesser or reduced effect on human health and the environment when compared to other products and services that serve the same purpose.
fuel type made by fermenting plant sugars; nearly all ethanol produced in the U.S. today are from corn sugars. See also "cellulosic ethanol", "E85", and "flex-fuel"
passenger vehicle with specially designed engine capable of running on E85 or pure gasoline, see also "ethanol" and "E85"
Fuel economy
fuel efficiency; a measure of fuel needed per unit of distance traveled, e.g. miles per gallon
Hazardous substance
1. material posing a threat to human health and/or the environment, that can be toxic, corrosive, ignitable, explosive, or chemically reactive 2. substance that must be reported to the EPA if released into the environment. 
hybrid-electric vehicle, see also "hybrid-electric"
vehicle marketed as an HEV but lacking advanced fuel economy features such as regenerative braking and all-electric drive mode, see also "hybrid-electric vehicle" and "advanced hybrid"
Hybrid-electric vehicle
fuel efficient vehicle type that combines an internal combustion engine with a battery-powered electric motor and other energy efficiency features
leaving the engine on while a vehicle is not in use
natural gas vehicle; i.e. vehicle fueled by natural gas, see also "CNG"
small particles and liquid droplets that can be inhaled and cause respiratory and heart disease
see "plug-in hybrid"
Plug-in hybrid
vehicle type similar to HEV, but with smaller gasoline engine and larger battery pac that can be charged using a standard electrical outlet and provide an all-electric driving range of between 20 and 60 miles; see also hybrid-electric vehicle
air pollution formed when sunlight reacts with oxides of nitrogen and hydrocarbons
Toxic substance
a chemical or mixture that may present an unreasonable risk of injury to health or the environment
Volatile organic compound (VOC)
organic compound that typically vaporizes at room temperature and participates in atmospheric photochemical reactions

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