Energy Intensity of Light Duty Vehicles and Motorcycles

KEY: Btu = British thermal unit; N = data do not exist; U = data are not available.

a Motorcycle was included in Light duty vehicle, short wheel base (previously Passenger car) in 1960 and 1965.
b 1960-99 data are for Passenger car and Other 2-axle, 4-tire vehicles, respectively. The data from 1960-2006 are not comparable to the data from 2007-15.
c Energy Intensity (Btu/passenger-mile) is calculated by converting the fuel consumption in gallons to the energy equivalent Btu units and dividing by the passenger-miles. The heat equivalent factor used for Btu...

Energy Intensity of Certificated Air Carriers, All Services (Metric)

KEY:  R = revised.

^a U.S. owned carriers only. Operations of foreign-owned carriers in or out of the United States not included.

Petroleum Oil Spills Impacting Navigable U.S. Waterways

KEY: N = data do not exist; R = revised.

^a Other vessels include commercial vessels, fishing boats, freight barges, freight ships, industrial vessels, oil recovery vessels, passenger vessels, unclassified public vessels, recreational boats, research vessels, school ships, tow and tug boats, mobile offshore drilling units, offshore supply vessels, publicly owned tank and freight ships, as well as vessels not fitting any particular class (unclassified).

^bOther nonvessel sources include deepwater ports, designated...

U.S. Carbon Dioxide Emissions from Energy Use by Sector

KEY:  CO2 = carbon dioxide; R = revised; Z = a value of zero, or value too small to report.

^a  Hydrocarbon Gas Liquids (HGL) includes ethane, propane, normal butane, isobutane, and natural gasoline, and their associated olefins. Excludes Liquified Natural Gas (LNG). 

Air Pollution Trends in Selected Metropolitan Statistical Areas

KEY:  AQI = Air Quality Index; R = revised.

Estimated U.S. Emissions of Sulfur Dioxide

KEY: P = preliminary; R = revised.

^aIndustrial processes consists of chemical and allied product manufacturing, metals processing, petroleum and related industries, and other industrial processes; solvent utilization; and storage and transport. 

Estimated U.S. Emissions of Carbon Monoxide

KEY: P = preliminary; R = revised. 

^aIndustrial processes consists of chemical and allied product manufacturing, metals processing, petroleum and related industries, other industrial processes; and solvent utilization, storage, and transport.

Estimated National Average Vehicle Emissions Rates per Vehicle by Vehicle Type Using Reformulated Gasoline and Diesel

KEY:  CO = carbon monoxide; HC = hydrocarbon; NOx = nitrogen oxide; RFG = reformulated gasoline; R = revised. 

Estimated U.S. Average Vehicle Emissions Rates per Vehicle by Vehicle Type Using Gasoline, Diesel, and Electric

KEY: Btu = British thermal unit; CO = carbon monoxide; CO2 = carbon dioxide; HC=hydrocarbons; N = data do not exist; NOx= nitrogen oxides; P = projection; PM2.5 = particulate matter with diameter <=2.5 micrometers; R = revised.

^a Total HC includes exhaust and evaporative emissions.

^b Motorcycle emission rates were last analyzed in 2010.

^c For electric vehicles, total HC and exhaust CO, NOx, PM2.5 and CO2 g/mile values are zero.

Federal Exhaust Emissions Standards for Locomotives

KEY: bhp-hr = brake horsepower-hour; CO = carbon monoxide; g = gram; HC = hydrocarbon; NOx = nitrogen oxides; PM = particulate matter; hp = horsepower; U = data are not available. 

^a Standards apply to locomotives that are propelled by engines with total rated horsepower (hp) of 750 kilowatts (kW) (1006 hp) or more, unless the owner chooses to have the equipment certified to meet the requirements of locomotives. This does not include vehicles propelled by engines with total rated horsepower of less than 750 kW (1006 hp); see the requirements in 40 Code of Federal...