40 CFR § 86.405-78 - Measurement system.

---
identifier: "/us/cfr/t40/s86.405-78"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 86.405-78 - Measurement system."
title_number: 40
title_name: "Protection of Environment"
section_number: "86.405-78"
section_name: "Measurement system."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "86"
part_name: "CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401-7671q."
cfr_part: "86"
---


# 86.405-78 Measurement system.

(a) This subpart and subpart F have been written using System International (SI) units. SI units will be used to determine compliance with these regulations. English equivalents have been indicated solely for the user's convenience.

(b) [Reserved]