Document ID: chunk:federal_register_of_legislation:F2024C00356:reg:21:p33
Version: federal_register_of_legislation:F2024C00356
Segment Type: reg
Provision Reference: reg 21 (pt 33/35)
Character Range: 378814–381803

than ±2 per cent.

              3. Specification
              3.1. The mass of the simulated total inertia I shall remain the same as the theoretical value of the equivalent inertia (see Appendix 1) within the following limits:
              3.1.1. 5 per cent of the theoretical value for each instantaneous value;
              3.1.2. 2 per cent of the theoretical value for the average value calculated for each sequence of the cycle.
               The limit given in paragraph 3.1.1. above is brought to 50 per cent for one second when starting and, for vehicles with manual transmission, for two seconds during gear changes.
              4. Verification procedure
              4.1. Verification is carried out during each test throughout the cycle defined in paragraph 6.1. of Annex 4a.
              4.2. However, if the requirements of paragraph 3. above are met, with instantaneous accelerations which are at least three times greater or smaller than the values obtained in the sequences of the theoretical cycle, the verification described above will not be necessary.
Annex 4a - Appendix 7
  Measurement of vehicle road load

  Resistance to progress of a vehicle measurement method on the road simulation on a chassis dynamometer
              1. Object of the methods
               The object of the methods defined below is to measure the resistance to progress of a vehicle at stabilized speeds on the road and to simulate this resistance on a dynamometer, in accordance with the conditions set out in paragraph 6.2.1. of Annex 4a.
              2. Definition of the road
               The road shall be level and sufficiently long to enable the measurements specified in this appendix to be made. The slope shall be constant to within ±0.1 per cent and shall not exceed 1.5 per cent.
              3. Atmospheric conditions
              3.1. Wind
               Testing shall be limited to wind speeds averaging less than 3 m/s with peak speeds of less than 5 m/s. In addition, the vector component of the wind speed across the test road shall be less than 2 m/s. Wind velocity shall be measured 0.7 m above the road surface.
              3.2. Humidity
               The road shall be dry.
              3.3. Pressure and Temperature
               Air density at the time of the test shall not deviate by more than ±7.5 per cent from the reference conditions, P = 100 kPa and T = 293.2 K.
              4. Vehicle preparation[8]
              4.1. Selection of the test vehicle
               If not all variants of a vehicle type are measured, the following criteria for the selection of the test vehicle shall be used.
              4.1.1. Body
               If there are different types of body, the test shall be performed on the least aerodynamic body. The manufacturer shall provide the necessary data for the selection.
              4.1.2. Tyres
               The widest tyre shall be chosen. If there are more than three tyre sizes, the widest minus