Trailer Standards for Fuel Efficiency FAQ

For box trailers longer than 50', including reefer trailers, the law requires a combination of:

  • Low-rolling resistance tires.
  • Automatic tire inflation systems.
  • Tire pressure monitoring systems (TPMS).
  • Aerodynamic devices and weight reduction technologies.

*This is an abbreviated version of the Frequently Asked Questions about Trailer Standards for Fuel Efficiency and Greenhouse Gas Emissions document. View the full document here*

The U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) jointly adopted new regulations for trailers on August 16, 2016, as part of the Phase 2 Heavy-Duty Greenhouse Gas Emissions and Fuel Efficiency Standards. As a follow up to a November 2016 workshop, EPA assembled this information to answer questions about the Phase 2 Trailer Program for manufacturers.

General Information

Who is responsible for complying with the trailer standards?

  • Trailer manufacturers are the primary regulated entities, while there are some requirements that affect companies importing trailers. Owners, operators and fleets do not have regulatory requirements under the Phase 2 rules other than to follow the trailer manufacturer’s instructions (such as specifications for tire replacement – See Question 18).
  • Device manufacturers, although not directly regulated, may request pre-approval of devices that improve trailer aerodynamics. See Questions 19 to 23.

When do the regulations take effect?

  • EPA’s standards apply for all regulated trailers produced on or after January 1, 2018.
  • Small business trailer manufacturers may delay compliance for one year, to January 1, 2019.
  • In addition to the 2018 standards, the trailer program has progressive stages of standards for Model Years 2021, 2024, and 2027. Office of Transportation and Air Quality EPA-420-F-17-901 February 2017 Frequently Asked Questions
  • A manufacturer’s Model Year for EPA/NHTSA compliance need not align with model years defined for marketing purposes or for other regulations. Model Year may align with calendar year. See the definition of Model Year at 40 CFR 1037.801.
  • NHTSA’s trailer program is optional until Model Year 2021.

Regulated Trailer Types

What types of trailers are regulated?

  • Long-box dry vans (greater than 50.0-feet in length)
  • Long-box refrigerated vans (greater than 50.0-feet in length)
  • Short-box dry vans (50.0 feet and shorter in length)
  • Short-box refrigerated vans (50.0 feet and shorter in length)
  • Tank trailers designed to transport liquids or gases
  • Flatbed trailers with continuous, flat platforms
  • Container chassis (all lengths)
  • See 40 CFR 1037.107, 1037.230(a)(3), and 1037.801

Which trailers are excluded?

  • Trailers built before January 1, 2018
  • Trailers pulled exclusively by pintle hook or hitch; not designed to be pulled by Class 7 or 8 tractors 2
  • Non-box trailers that do not meet the definition of flatbed trailers, tank trailers or container chassis
  • Trailers with four or more axles, and trailers less than 35-feet with three axles
  • Trailers intended for temporary or permanent residence, office space or other work space
  • Trailers with a gap of 120 inches between adjacent axle centerlines
  • See 40 CFR 1037.5

Trailer Types, Technology Options, and Measuring Trailer Performance

Can I still use my old trailer? Do I have to add technologies to my old trailer?

  • These standards only apply to new trailers. There are no requirements for owners or operators to retire or retrofit trailers.

Do new trailers need specific technologies to meet the standards?

  • Maybe, it depends on what type of trailer it is.
  • Non-box trailer standards for flatbed trailers, tank trailers and container chassis and standards for box vans designated as “non-aero” are design standards that require trailer manufacturers to install a certain level of lower rolling resistance tires and a tire pressure system (either TPMS or ATIS).
  • The design standards do not require the use of any specific make or model of technology.
  • Box van standards (other than “non-aero”) are performance-based standards. Manufacturers can meet the overall trailer performance requirements with any combination of technologies, including the use of aerodynamic improvements, lower rolling resistance tires, tire pressure systems (ATIS or TPMS) weight reduction, or other “off-cycle technology.” Manufacturers have several options of technologies that can help them meet the performance standards for a given model year:
  • The performance standards do not require the use of any specific technology type, make, or model Manufacturers must demonstrate that the trailer meets the performance standard.

Does the end-user have to install the same LRR tires when they need replacement?

  • Trailer manufacturers must include sufficient rolling resistance information in their maintenance instructions to allow end-users to purchase replacement tires that meet the appropriate performance specifications.
  • End-users can replace tires with tires of a different make or model as long as their rolling resistance performance is equivalent to or better than the original tires’ performance.


Does my regulated trailer need a label?

  • Yes, all regulated trailers are required to have a permanent label indicating that they are certified vehicles.
  • See 40 CFR 1037.135 and Appendix III to Part 1037.

Does the label need to be in a specific location on the trailer?

  • We do not specify a location for the label, but it must be easily visible for inspection.

Do I have to create a separate label or can I place emissions information on my current label?

  • We do not require emissions information be on a stand-alone label
  • The information required by 40 CFR 1037.135 can be added to an existing label as long as it meets the durability requirements outlined in 40 CFR 1068.45.

What information must be included on the label? Must it list all devices used on the trailer? Must it include compliance equation results?

  • Specific requirements for the label are outlined in 40 CFR 1037.135.
  • The label must list the components installed on the trailer for compliance with the standards: For every trailer where any of the technologies listed in Appendix III to Part 1037 are used to demonstrate compliance during certification of that configuration, the Emission Control Identifier must be listed on the label.
  • If a manufacturer uses technologies from Appendix III but does not rely on that technology to demonstrate compliance, that technology does not need to be included on the label.
  • Many weight reduction components and off-cycle technologies are not listed in Appendix III and therefore are not required to be listed on the label.
  • The label does not include compliance equation results.

Do I need to affix a label on excluded trailers?

  • No label is required for trailers excluded under 40 CFR 1037.5.
  • MY 2018 trailers excluded as part of the small business flexibility outlined in 40 CFR 1037.150(c) must have a label with the following statement: “THIS VEHICLE IS EXCLUDED UNDER 40 CFR 1037.150(c).”

Do I need to affix a label on trailers exempted using the transitional allowance for MYs 2018-2026?

  • Yes, trailers exempt under the transitional allowance provision outlined in 40 CFR 1037.150(v) must include a permanent label that meets the requirements of 40 CFR 1068.45(a), the corporate name of the trailer manufacturer, and a statement that the trailer is exempt under 40 CFR 1037.150.

Do we need a label for trailers built for export?

  • Labels are required for trailers that will be exported, but the labels can be removable (see 40 CFR 1068.230).

Other Resources

How can I get more information?

  • Read the entire FAQ document compiled by the EPA and NHTSA here
  • For further information about complying with the trailer regulations, please contact OTAQ’s Compliance Division at:

U.S. Environmental Protection Agency Office of Transportation and Air Quality 2000 Traverwood Drive Ann Arbor, MI 48105 E-mail: