Transportation and Air Quality
- What is the federally mandated warranty for emission controls on my car?
- Why is there ethanol in gasoline?
- Does the fuel used in fuel economy testing contain ethanol?
What's New in OTAQ
OTAQ Recent Additions
- March 2: New fun, interactive content added to our Green Vehicle Guide. Learn about hydrogen FCVs, alternative fuels, and why your mileage may vary.
OTAQ Press Releases
- February 19, 2015: U.S. EPA and Customs seize and export more than 730 illegal vehicles, engines at LA/Long Beach Port
- February 18, 2015: Six Kansas School Districts Receive $355,000 to Replace Old Diesel Buses with New, Clean Buses
- February 18, 2015: Ten Missouri School Districts Receive $515,000 to Replace Old Diesel Buses with New, Clean Buses
OTAQ Federal Register Notices
- February 25, 2015: Information Collection Request Submitted to OMB for Review and Approval; Comment Request; Reporting and Recordkeeping Requirements for Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles (Renewal)
- February 23, 2015: Proposed Information Collection Request; Comment Request; Transportation Conformity Determinations for Federally Funded and Approved Transportation Plans, Programs and Projects
- February 19, 2015: Proposed Rule: Amendments Related to: Tier 3 Motor Vehicle Emission and Fuel Standards, Nonroad Engine and Equipment Programs, and MARPOL Annex VI Implementation
EPA's Office of Transportation and Air Quality protects public health and the environment by regulating air pollution from motor vehicles, engines, and the fuels used to operate them, and by encouraging travel choices that minimize emissions. These "mobile sources" include cars and light trucks, heavy trucks and buses, nonroad engines, equipment, and vehicles. For more information see:
- About the Office of Transportation and Air Quality (OTAQ)
- About the National Vehicle and Fuel Emissions Laboratory (NVFEL)
OTAQ's top sites
OTAQ's programs and website topics (A detailed list of programs and topics is on our site map.)
Overview:Pollutants & Programs
Information on how much air pollution, air toxics, and greenhouse gases are emitted by mobile sources, the programs OTAQ has undertaken to control these emissions, and the impact of those programs on air quality and climate change.
On-Road Vehicles & Engines
Information about fuel economy, emission standards and regulations, emission recall, certification and compliance, inspection and maintenance, diesel retrofit, evaluating the benefits of inventions designed to reduce emissions, and importing vehicles and engines.
Nonroad Engines, Equipment
Information about nonroad engines, equipment and vehicles: emission standards and regulations, certification and compliance, and diesel retrofit programs.
- Diesel Boats & Ships
- Gasoline Boats & Personal Watercraft
- Nonroad Diesel Equipment
- Forklifts, Generators & Compressors
- Lawn & Garden
- Snowmobiles, Dirt Bikes, & ATVs
Fuels & Fuel Additives
State & Local Transportation
Modeling, Testing, & Research
Information on modeling and inventories for estimating emissions from highway vehicles, nonroad sources, and fuels; testing and measuring emissions; research into clean automotive technologies; and emission factors research.