Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p15
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 15/108)
Character Range: 925592–928677

that paragraph and corrected according to paragraph 4.5.5. of this annex. The coastdown test result of a test vehicle shall be the arithmetic average of the road load coefficients of its two separate coastdown tests. If more than two coastdown tests are necessary to fulfil the approval of facilities' criteria, all valid tests shall be averaged.

              6.2.3. Measurement with the wind tunnel method according to paragraphs 6.3. to 6.7. inclusive of this annex shall be performed on the same three vehicles as selected in paragraph 6.2.1. of this annex and in the same conditions, and the resulting road load coefficients, f0, f1 and f2, shall be determined.

              If the manufacturer chooses to use one or more of the available alternative procedures within the wind tunnel method (i.e. paragraph 6.5.2.1. on preconditioning, paragraphs 6.5.2.2. and 6.5.2.3. on the procedure, including paragraph 6.5.2.3.3. on dynamometer setting), these procedures shall also be used also for the approval of the facilities.

              6.2.4. Approval criteria

              The facility or combination of facilities used shall be approved if both of the following two criteria are fulfilled:

                  (a) The difference in cycle energy, expressed as εk, between the wind tunnel method and the coastdown method shall be within ±0.05 for each of the three vehicles k according to the following equation:

              where:

                     εk is the difference in cycle energy over a complete Class 3 WLTC for vehicle k between the wind tunnel method and the coastdown method, per cent;

                     Ek,WTM is the cycle energy over a complete Class 3 WLTC for vehicle k, calculated with the road load derived from the wind tunnel method (WTM) calculated according to paragraph 5. of Annex B7, J;

                     Ek,coastdown is the cycle energy over a complete Class 3 WLTC for vehicle k, calculated with the road load derived from the coastdown method calculated according to paragraph 5. of Annex B7, J.; and

                  (b) The arithmetic average  of the three differences shall be within 0.02.

              The approval shall be recorded by the responsible authority including measurement data and the facilities concerned.

              The facility may be used for road load determination for a maximum of two years after the approval has been granted.

              Each combination of roller chassis dynamometer or moving belt and wind tunnel shall be approved separately.

              Every combination of wind speeds (see paragraph 6.4.3. of this annex) used for the determination of road load values shall be validated separately.

              6.3. Vehicle preparation and temperature

              Conditioning and preparation of the vehicle shall be performed according to paragraphs 4.2.1. and 4.2.2. of this annex and applies to both the flat belt or roller chassis dynamometers and the wind tunnel measurements.

              In the case that the alternative warm-up procedure described in paragraph 6.5.2.1. of