---
kind: "section"
citation: "40 C.F.R. § 1066.805"
title: "40"
number: "1066.805"
heading: "Road-load power, test weight, and inertia weight class determination."
url: "https://uscodex.org/cfr/40/1066.805"
---

# §1066.805. Road-load power, test weight, and inertia weight class determination.

- (a) Simulate a vehicle's test weight on the dynamometer using the appropriate equivalent test weight shown in Table 1 of this section. Equivalent test weights are established according to each vehicle's test weight basis, as described in [paragraph (b)](#b) of this section. Table 1 also specifies the inertia weight class corresponding to each equivalent test weight; the inertia weight class allows for grouping vehicles with a range of equivalent test weights. Table 1 follows:
- (b) **The test weight basis for non-MDPV heavy-duty vehicles is “adjusted loaded vehicle weight”.** For all other vehicles, the test weight basis for establishing equivalent test weight is “loaded vehicle weight”. These load terms are defined in [40 CFR 86.1803](/cfr/40/86.1803.md).
- (c) For FTP, US06, SC03, New York City Cycle, HFET, and LA-92 testing, determine road-load forces for each test vehicle at speeds between 9.3 and 71.5 miles per hour. The road-load force must represent vehicle operation on a smooth, level road with no wind or calm winds, no precipitation, an ambient temperature of approximately 20 °C, and atmospheric pressure of 98.21 kPa. You may extrapolate road-load force for speeds below 9.3 mi/hr.

## Notes

### Amendments

[79 FR 23823, Apr. 28, 2016, as amended at 81 FR 74213, Oct. 25, 2016; 89 FR 18214, Apr. 18, 2024]

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 79 FR 23823, Apr. 28, 2014, unless otherwise noted.

### Amendments

[79 FR 23823, Apr. 28, 2016, as amended at 81 FR 74213, Oct. 25, 2016; 89 FR 18214, Apr. 18, 2024]