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  2. Regulations for Emissions from Vehicles and Engines

Regulations for Emissions from Heavy Equipment with Compression-Ignition (Diesel) Engines

Related Topics
  • Controlling air pollution from stationary engines
  • Emission Standards Reference Guide
  • Frequently Asked Questions from Owners and Operators of Nonroad Engines, Vehicles, and Equipment Certified to EPA Standards (pdf) (475 KB, February 2018, EPA-420-F-18-004)
  • How to Maintain or Rebuild Engines Certified to EPA Standards (pdf) (466 KB, February 2018, EPA-420-F-18-003)
  • Regulations for emissions from heavy equipment with spark-ignition engines
On this page:
  • Overview
  • List of related e-CFR links
  • List of related regulations

Overview

This page provides regulations for nonroad compression-ignition (diesel) engines that are used in machines that perform a wide range of important jobs. These include excavators and other construction equipment, farm tractors and other agricultural equipment, forklifts, airport ground service equipment, and utility equipment such as generators, pumps, and compressors.

EPA has adopted multiple tiers of emission standards. Most recently, we adopted a comprehensive national program to reduce emissions from nonroad diesel engines by integrating engine and fuel controls as a system to gain the greatest emission reductions. To meet these Tier 4 emission standards, engine manufacturers will produce new engines with advanced emission control technologies. Because the emission control devices can be damaged by sulfur, we have also adopted requirements for in-use diesel fuel to decrease sulfur levels by more than 99 percent. The resulting Ultra Low Sulfur Diesel Fuel has a maximum sulfur concentration of 15 parts per million.


Basic Research

Data for reproducing real-world activity of various nonroad compression ignition (CI, diesel) engines in a controlled setting is available on this page:
EPA Nonregulatory Nonroad Duty Cycles


List of Related e-CFR Links

See the Electronic Code of Federal Regulations (e-CFR) for the full text of current regulations that apply to large CI engines.

e-CFR link Summary of what you will find
40 CFR Part 1039 Tier 4 emission standards and certification requirements
40 CFR Part 1065 Exhaust emission test procedures (for lab and in-field testing)
40 CFR Part 1068 General compliance provisions

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List of Related Regulations

Below is a list of all regulations related to emissions from heavy equipment with compression-ignition (diesel) engines.

Help
For help on using the table:
  • View Table Instructions
Click the regulation titles for additional information, including:
  • Rule summaries;
  • Regulatory impact analyses;
  • Comment summaries;
  • Rule histories (including proposed rules); and 
  • Fact sheets.*

*Note: Rule-related materials vary by rule.

Regulation Title Referenced Tier Level(s)
(if applicable)
Regulation Date
(Year/Month)
Partial Withdrawal and Final Rule for the Nonroad Diesel Technical Amendments and Tier 3 Technical Relief Provision   2007/12
Direct Final Rule for Control of Air Pollution From New Motor Vehicles; Revisions to Motor Vehicle Diesel Fuel Sulfur Transition Provisions; and Technical Amendments to the Highway Diesel, Nonroad Diesel, and Tier 2 Gasoline Programs   2005/11
Final Rule for Test Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments   2005/07
Final Rule for Control of Emissions of Air Pollution From Nonroad Diesel Engines Tier 2, Tier 3 1998/10
Final Rule for Nonroad Technical Amendments   2014/02
Direct Final Rule: Amendments to Emission Requirements Applicable to New Nonroad CI Engines at or Above 37 Kilowatts: Provisions for Replacement CI Engines and the Use of On-Highway CI Engines in Nonroad Vehicles   1996/11
Final Rule for Determination of Significance for Nonroad Sources and Emission Standards for New Nonroad Compression-Ignition Engine At or Above 37 Kilowatts Tier 1 1994/06
Direct Final Rule: Nonroad Diesel Technical Amendments and Tier 3 Technical Relief Provision Tier 3 2007/09
Final Rule for Emergency Vehicle Rule—SCR Maintenance and Regulatory Flexibility for Nonroad Equipment   2014/08
Direct Final Rule for Heavy-Duty Engine and Vehicle, and Nonroad Technical Amendments   2013/06
Direct Final Rule for Heavy-Duty Highway Program: Revisions for Emergency Vehicles   2012/06
Final Rule for Control of Emissions From New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder   2010/04
Final Rule for Control of Emissions From New Marine Compression-Ignition Engines at or Above 2.5 Liters Per Cylinder Tier 1 2003/02
Greenhouse Gas Reporting Program (GHGRP)   2009/10
Final Rule for Control of Emissions From Nonroad Spark-Ignition Engines and Equipment   2008/10
Final Rule for Control of Emissions of Air Pollution From Locomotive Engines and Marine Compression-Ignition Engines Less Than 30 Liters per Cylinder   2008/06
Final Rule for Control of Emissions of Air Pollution from Nonroad Diesel Engines and Fuel Tier 4 2004/06

Regulations for Emissions from Vehicles and Engines

  • Onroad
    • Passenger Vehicles
    • Commercial Trucks & Buses
    • Motorcycles
  • Nonroad
    • Aircraft
    • Heavy Equipment
    • Locomotives
    • Marine
    • Recreational Vehicles
    • Small Equipment & Tools
  • Greenhouse Gas
Contact Us About Regulations for Emissions from Vehicles and Engines
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Last updated on April 1, 2025
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