Heavy Trucks, Buses, and Engines

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This page presents general information about heavy-duty highway engines, such as those used in trucks and buses, and their emissions. There is also information regarding EPA's diesel programs, regulations, and retrofit/rebuild programs.

General Information
Diesel Programs and Regulations
Related Links

General Information

Diesel Exhaust in the United States (PDF) (4 pp, 394K, EPA420-F-03-022, September 2002)
What You Should Know About Diesel Exhaust and School Bus Idling (PDF) (2 pp, 574K, EPA420-F-03-021, June 2003)
Emission Standards Reference Guide for Heavy-Duty and Nonroad Engines (PDF) (16 pp, 145K, EPA420-F-97-014, September 1997) This document provides a detailed listing of current and proposed federal and California standards for 1990 model years and later.

Diesel Programs and Regulations

Nonconformance Penalties for On-Highway Heavy-Duty Diesel Engines (published January 31, 2012)
- Fact Sheet: Non-Conformance Penalties for Heavy-Duty Diesel Engines Subject to the 2010 NOx Emission Standard (PDF) (4 pp, 797K, EPA-420-F-12-001, January 2012)
- Interim Final Rule (PDF) (10 pp, 281K, published January 31, 2012)
- Notice of Proposed Rulemaking (PDF) (32 pp, 401K, published January 31, 2012)
- Interim and Proposed Technical Support Document: Nonconformance Penalties for On-Highway Heavy-Duty Engines (PDF) (51 pp, 1.0MB, EPA-420-R-12-004, January 2012)
- Frequently-Asked-Question(s) about the Nonconformance Penalties
Revisions to In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and Instrumentation; Not-to-Exceed Emission Standards; and Technical Amendments for Off-Highway Engines (published November 8, 2010)
- Fact Sheet: Amendments to In-Use Testing for Heavy-Duty Diesels, Measurement and Instrumentation, and Off-Highway Engine Regulations | PDF Version (3 pp, 687K, EPA-420-F-10-042, October 2010)
- Direct Final Rule | PDF Version (20 pp, 358K, published November 8, 2010)
- Notice of Proposed Rulemaking | PDF Version (8 pp, 173K, published November 8, 2010)
- Test Plan to Determine PEMS Measurement Allowance for the PM Emissions Regulated under the Manufacturer-Run Heavy-Duty Diesel Engine in-use Testing Program (PDF) (53 pp, 586K, EPA-420-B-10-901, August 2010)
- Final Report: PM-PEMS Measurement Allowance Determination (PDF) (317 pp, 6.17MB, EPA-420-R-10-902, August 2010)
Notice: Control of Emissions From New Highway Vehicles and Engines: Approval of New Scheduled Maintenance for Selective Catalyst Reduction Technologies (PDF) (4 pp; 60K; November 9, 2009)
Direct Final Rule In-Use Testing for Heavy-Duty Diesel Engines and Vehicles: Emission Measurement Accuracy Margins for Portable Emission Measurement Systems and Program Revisions (published March 13, 2008)
- Fact Sheet: Amendments to Manufacturer-Run, Heavy-Duty Highway In-Use Engine and Vehicle Testing | PDF Version (3 pp, 96K, EPA420-F-08-011, February 2008)
- Direct Final Rule | PDF Version (12 pp, 112K)
- Notice of Proposed Rulemaking | PDF Version (6 pp, 79K)
- Determination of PEMS Measurement Allowances for Gaseous Emissions Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program (754 pp, 9.2MB, EPA420-R-08-005, February 2008)
- Additional Analyses of the Monte Carlo Model Developed for the Determination of PEMS Measurement Allowances for Gaseous Emissions Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program (PDF) (92 pp, 834K, EPA420-R-07-010, August 2007)

2007 Technical Amendments (published May 18, 2007)
- Regulation (Entire document PDF) (297 pp, 1.53MB) or:
  - Pages 28097-28146 | PDF Version (372K)
  - Pages 28147-28196 | PDF Version (469K)
  - Pages 28197-28246 | PDF Version (799K)
  - Pages 28247-28296 | PDF Version (882K)
  - Pages 28297-28346 | PDF Version (874K)
  - Pages 28347-28393 | PDF Version (871K)
- Redline version highlighting proposed changes for 40 CFR 1065 (PDF) (83 pp, 1.3MB)
Final Rule: Control of Emissions from New and In-Use Highway Vehicles and Engines: Approval of New Scheduled Maintenance for Diesel Particulate Filters in Certain Applications | PDF Version (3 pp, 94K) (published March 7, 2006)
Amended Regulations for Diesel Fuels
- Final Rule: Revisions to Motor Vehicle Diesel Fuel Sulfur Transition Provisions, and Technical Amendments to the Highway Diesel, Nonroad Diesel, and Tier 2 Gasoline Programs (published November 22, 2005)
- Final Rule: To Establish a Transition Program for Low-Sulfur Diesel in Alaska (published June 6, 2006)
- Final Rule: To Amend the Nonroad Diesel and Highway Diesel Fuel Regulations (published July 15, 2005)
Final Rule: In-Use Testing for Heavy-Duty Engines and Vehicles (published June 14, 2005)
- Press Release (issued June 14, 2005)
- Fact Sheet: Final Rule on In-Use Testing Program for Heavy-Duty Diesel Engines and Vehicles | PDF Version (4 pp, 42K, EPA420-F-05-021, June 2005)
- Federal Register Notice | PDF Version (34 pp, 552K)
- Technical Support Document (48 pp, 663K, EPA420-R-05-006, June 2005)
- Summary & Analysis of Comments (PDF) (50 pp, 447K, EPA420-R-05-007, June 2005)
- Memorandum of Agreement: Program to Develop Emission Measurement Accuracy Margins for Heavy-Duty In-Use Testing (PDF) (11 pp, 170K, May 2005)
- Test Plan to Determine PEMS Measurement Allowances for the Gaseous Emissions Regulated Under the Manufacturer-Run Heavy-Duty Diesel Engine In-Use Testing Program (PDF) (71 pp, 13.8 MB, May 2005)
- See proposed rule and supporting documents (published June 10, 2004)
Final 2005 Technical Amendments: Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments (published July 13, 2005)
- Fact Sheet: Changed Test Procedures for Nonroad Engines and Heavy-Duty Highway Engines | PDF Version (4 pp, 134K, EPA420-F-05-036, July 2005)
- Final Rule (July 13, 2005):
  - Pages 40419-40468 | PDF Version (50 pp, 949K)
  - Pages 40469-40518 | PDF Version (50 pp, 938K)
  - Pages 40519-40568 | PDF Version (50 pp, 6.1MB)
  - Pages 40569-40614 | PDF Version (50 pp, 1.81MB)
- Technical Support Document and Summary & Analysis of Comments (PDF) (115 pp, 1.7MB, EPA420-R-05-008, June 2005)
- See Proposed Technical Amendments (published September 10, 2004)

Final Rule: Nonconformance Penalties for 2004 and Later Model Year Emission Standards for Heavy-Duty Diesel Engines and Heavy-Duty Diesel Vehicles (published August 8, 2002)
- Nonconformance Penalties for Heavy-Duty Diesel Engines (PDF) (4 pp, 14K, EPA420-F-02-025, August 2002)
- Preamble and Regulatory (PDF) (32 pp, 76K)
- Technical Support Document (PDF) (61 pp, 193K, EPA420-R-02-021)
- Response to Comments (PDF) (29 pp, 127K, EPA420-R-02-020)
- Press Release (issued August 8, 2002)
- See proposed rule and supporting documents (published January 16, 2002)
2007 Heavy-Duty Highway Final Rule: Heavy-duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements - Final Rule (published January 18, 2001)
Final Rule: Updated Emission Standards for 2004 and Later Heavy-duty Highway Engines and Vehicles (published October 6, 2000)
- Fact Sheet: Final Emission Standards for 2004 and Later Model Year Highway Heavy-duty Vehicles and Engines (PDF) (4 pp, 12K, EPA-420-F-00-026, July 2000)
- Preamble and Regulatory Text | PDF Version (84 pp, 839K)
- Regulatory Impact Analysis (PDF) (157 pp, 575K, EPA420-R-00-010, July 2000)
- Response to Comments (PDF) (152 pp, 460K, EPA420-R-00-011, July 2000)
- See Proposed Emission Standards for the proposed rule, fact sheets, and regulatory support documents.

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General Information

Diesel Programs and Regulations

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