Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:6:p3
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 6 (pt 3/4)
Character Range: 880890–884013

High3 + Extra High3  118 km/h                      NA
Low3 + Medium3 + High3  88 km/h                               Extra High (118 km/h)

              4.2.4.1.3. Criterion for stable condition
           Refer to paragraph 4.3.1.4.2. of this annex.
              4.3. Measurement and calculation of road load using the coastdown method
              The road load shall be determined by using either the stationary anemometry (paragraph 4.3.1. of this annex) or the on-board anemometry (paragraph 4.3.2. of this annex) method.
              4.3.1. Coastdown method using stationary anemometry
              4.3.1.1. Selection of reference speeds for road load curve determination
              Reference speeds for road load determination shall be selected according to paragraph 2.2. of this annex.
              4.3.1.2. Data collection
              During the test, elapsed time and vehicle speed shall be measured at a minimum frequency of 10 Hz.
              4.3.1.3. Vehicle coastdown procedure
              4.3.1.3.1. Following the vehicle warm-up procedure described in paragraph 4.2.4. of this annex and immediately prior to each coastdown run, the vehicle shall be accelerated to 10 to 15 km/h above the highest reference speed and shall be driven at that speed for a maximum of 1 minute. After that, the coastdown run shall be started immediately.
              4.3.1.3.2. During a coastdown run, the transmission shall be in neutral. Any movement of the steering wheel shall be avoided as much as possible, and the vehicle brakes shall not be operated.
              4.3.1.3.3. The test shall be repeated until the coastdown data satisfy the statistical precision requirements as specified in paragraph 4.3.1.4.2. of this annex.
              4.3.1.3.4. Although it is recommended that each coastdown run should be performed without interruption, if data cannot be collected in a single run for all the reference speed points, the coastdown test may be performed with coastdown runs where the first and last reference speeds are not necessarily the highest and lowest reference speeds. In this case, the following additional requirements shall apply:
                  (a) At least one reference speed in each coastdown run shall overlap with the immediately higher speed range coastdown run. This reference speed shall be referred to as a split point;
                  (b) At each overlapped reference speed, the average force of the immediately lower speed coastdown run shall not deviate from the average force of the immediately higher speed coastdown run by ±10 N or ± 5 per cent, whichever is greater;
                  (c)  Overlapped reference speed data of the lower speed coastdown run shall be used only for checking criterion (b) and shall be excluded from evaluation of the statistical precision as defined in paragraph 4.3.1.4.2. of this annex;
                  (d)  The overlapped speed may be less than 10 km/h but shall not be less than 5 km/h. In this case, overlap criterion (b) shall be checked by either extrapolating the polynomial curves for the lower and higher speed segment to