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Vehicle and Engine Certification

Heavy-Duty Highway Tractors and Vocational Vehicles: Family Naming Conventions

To determine Positions 1-4 of your Vehicle Family name, see:

Use the table below to create Positions 5-12:

Location in Family Name Code/Value Description or Instructions
Position 5 2 Industry sector code for all "Complete Heavy-Duty Highway Vehicles (tractors and vocational vehicles >14,000 pounds GVWR) "
Positions 6-9 VOCV Vocational vehicle
TRAC Tractor
  PWRT Powertrain
Positions 10-12 *** Enter any combination of valid characters in order to provide a unique identification for your family name.
  • Vocational tractors subject to the provisions of 40 CFR §1037.630 remain part of the vocational regulatory subcategory. Family names for these vehicles should reflect the vehicle type "Vocational Vehicle".
  • This also includes heavy-duty highway vehicles at or below 14,000 pounds GVWR that are not tested on a chassis-dynamometer for certification under 40 CFR Part 1037 (i.e., certified to the requirements and standards of §1037.105, per §1037.104(f)).  
  • This naming convention is also used to identify powertrain testing configurations as described in 1037.231 (encompassing engine, transmission, and axle) when powertrain testing is used for certification of any vehicles within a family.