§1037.527. Aerodynamic measurements for vocational vehicles.
40 C.F.R. § 1037.527
This section describes an optional methodology for determining improved aerodynamic drag area, CdA, for vocational vehicles, as described in § 1037.520(m), rather than using the assigned values. A vocational vehicle's aerodynamic performance is based on a DCdA value relative to a baseline vehicle. Determine a DdA value by performing A to B testing as follows:
Use any of the procedures described in this subpart, with appropriate adjustments, for calculating drag area.
Determine a baseline CdA value for a vehicle representing a production configuration without the aerodynamic improvement. Repeat this testing and measure CdA for a vehicle with the improved aerodynamic design.
Use good engineering judgment to perform paired tests that accurately demonstrate the reduction in aerodynamic drag associated with the improved design.
Measure <I>C</I><I>d</I><I>A</I> in m 2 to two decimal places. Calculate DdA by subtracting the drag area for the test vehicle from the drag area for the baseline vehicle.
Notes, amendments, and revision history
Amendments
[89 FR 29783, Apr. 22, 2024]
Authority
Authority: 42 U.S.C. 7401—7671q.
Source
Source: 81 FR 74048, Oct. 25, 2016, unless otherwise noted.
Amendments
[89 FR 29783, Apr. 22, 2024]