40 CFR § 205.55-3 - Configuration identification.

---
identifier: "/us/cfr/t40/s205.55-3"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 205.55-3 - Configuration identification."
title_number: 40
title_name: "Protection of Environment"
section_number: "205.55-3"
section_name: "Configuration identification."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "G"
subchapter_name: "NOISE ABATEMENT PROGRAMS"
part_number: "205"
part_name: "TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Secs. 6, 10, 11, 13, Pub. L. 92-574, 86 Stat. 1234 (42 U.S.C. 4905, 4909, 4910, 4912)."
regulatory_source: "41 FR 15544, Apr. 13, 1976, unless otherwise noted."
cfr_part: "205"
---


# 205.55-3 Configuration identification.

(a) A separate vehicle configuration shall be determined by each combination of the following parameters:

(1) *Exhaust system configuration.* (i) Single vertical.

(ii) Dual vertical.

(iii) Single horizontal.

(iv) Dual horizontal.

(2) *Air induction system* (*engine*). (i) Natural.

(ii) Turbocharged.

(3) *Fan.* (i) Diameter.

(ii) Drive.

(*a*) Direct.

(*b*) Thermostatic.

(iii) Max fan rpm.

(4) *Engine manufacturer's horsepower rating.*

(5) *Cab characteristic.* (i) Sleeper.

(ii) Non sleeper.

(6) *Category parameters listed in § 205.55-2.*