On-Road Heavy-Duty and Off-Road Compression Ignition Certification Programs: Family Naming Guidance

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Naming Guidance for Engine Families (On-Road Heavy-Duty/Off-Road Compression Ignition), Evaporative/Refueling Families, and GHG Vehicle Families

Each engine family (On-Road Heavy-Duty/Off-Road Compression Ignition), evaporative/refueling family, and GHG vehicle family must be assigned a unique family name by the manufacturer, in accordance with the established EPA family naming conventions. Refer to the EPA documents:

Year

Document #

Document Title

2009CISD-07-03

"EPA Standardized Naming Conventions for Model Year 2009 and Later Engine Family and Test Group Names, Evaporative/Refueling Family Names, and Permeation Family Names"

2013CD-12-01"EPA Standardized Naming Conventions for Model Year 2013 and Later Heavy‑Duty Highway Vehicle Family Names" 
2015CD-15-19"Consolidation of EPA Standardized Naming Conventions for Engine Family, Test Group, Evaporative/Refueling Family, Permeation Family, Emission Family, and Durability Group"

2017

CD-17-10"Update of EPA Standardized Naming Conventions for Engine Family, Test Group, Evaporative/Refueling Family, Permeation Family, Emission Family, and Durability Group"
2020CD-2020-08"Update of EPA Standardized Naming Conventions for Heavy-Duty Engine and Vehicle Engine Family and Power Train Family"

 

The following figure identifies the different sections of the 12-character family name and describes the purpose of each section. 

Visual representation of 12-character family naming convention

 

 

 

 

 

A few important tips:

  • Model Year – Use Table 2 of the EPA guidance to select Model Year code
  • Manufacturer Code – Use the 3-character alphanumeric manufacturer code assigned to the company by the U.S. EPA.
  • Industry Sector Code – Use Table 4 of the EPA guidance to select the correct industry sector code. For example, use “2” for Vocational Vehicles or Heavy-Duty Zero Emission Powertrains, “H” for HD Highway Diesel Engines, "E" for HD Highway Otto Cycle engines and "L" for Nonroad Compression-Ignition Engines (California Off-Road). 
  • Engine Displacement/Family Type Code – Use Table 5 of the EPA guidance to select engine displacement or family type of descriptor. For example “VOCV or TRAC” for vocational vehicle or tractor, “XX.X” for displacement units in liters or “XXXX” for the engine displacement units in cubic inches.  For dual or variable displacement families, enter the maximum displacement. 
  • Manufacturer Assigned Characters - Manufacturer-assigned characters used to create a unique family name.

Please see EPA's Family Naming Conventions webpage for more information and guidance on the family naming conventions.