Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:6:p1
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 6 (pt 1/4)
Character Range: 875201–878428

6                                                                                                                                                                                                                    RRC = 12.9                                              RRC = 11.2                                              RRC = 8.5
* For Level 1A only: In case the actual RRC value is lower than this value, the actual rolling resistance value of the tyre or any higher value up to the RRC value indicated here shall be used for interpolation.

              If the interpolation method is applied to rolling resistance, the actual rolling resistance values for the tyres fitted to the test vehicles L and H shall be used as input for the interpolation method. For an individual vehicle within an interpolation family, the RRC value for the energy efficiency class of the tyres fitted shall be used.

              In the case where individual vehicles can be supplied with a complete set of standard wheels and tyres and in addition a complete set of snow tyres (marked with 3 Peaked Mountain and Snowflake – 3PMS) with or without wheels, the additional wheels/tyres shall not be considered as optional equipment.

              4.2.2.2. Tyre condition

           Tyres used for the test shall:

           (a) Not be older than 2 years after the production date;

                  (b) Not be specially conditioned or treated (e.g. heated or artificially aged), with the exception of grinding in the original shape of the tread;
                  (c) Be run-in on a road for at least 200 km before road load determination;
                  (d) Have a constant tread depth before the test between 100 and 80 per cent of the original tread depth at any point over the full tread width of the tyre.
              After measurement of tread depth, the driving distance shall be limited to 500 km. If 500 km are exceeded, the tread depth shall be measured again.
              4.2.2.3. Tyre pressure
              The front and rear tyres shall be inflated to the lower limit of the tyre pressure range for the respective axle for the selected tyre at the coastdown test mass, as specified by the vehicle manufacturer.
              4.2.2.3.1. Tyre pressure adjustment
              If the difference between ambient and soak temperature is more than 5 °C, the tyre pressure shall be adjusted as follows:
                  (a) The tyres shall be soaked for more than 1 hour at 10 per cent above the target pressure;
                  (b) Prior to testing, the tyre pressure shall be reduced to the inflation pressure as specified in paragraph 4.2.2.3. of this annex, adjusted for difference between the soaking environment temperature and the ambient test temperature at a rate of 0.8 kPa per 1 °C using the following equation:
              where:
                      is the tyre pressure adjustment added to the tyre pressure defined in paragraph 4.2.2.3. of this annex, kPa;
                  0.8 is the pressure adjustment factor, kPa/°C;
                  Tsoak is the tyre soaking temperature, °C;
                  Tamb is the test ambient temperature, °C.
                  (c) Between the pressure adjustment and