Division 3.4.1 F1
Road load and dynamometer settings shall be as specified in Sub-Annex 4, including the requirement for the room temperature to be at 23 °C.
To take account of the difference in air density at 14 °C when compared to the air density at 20 °C, the chassis dynamometer shall be set as specified in paragraphs 7. and 8. of Sub-Annex 4 with the exception that f2_TReg from the following equation shall be used as the target coefficient Ct.
f2_TReg = f2 × (Tref + 273)/(Treg + 273)
where:
is the second order road load coefficient, at reference conditions, N/(km/h)2;
is the road load reference temperature as specified in paragraph 3.2.10. of this Annex, C;
is the regional temperature, as defined in paragraph 3.1.1., C.
In the case that a valid chassis dynamometer setting of the 23 °C test is available, the second order chassis dynamometer coefficient of Cd shall be adapted in accordance with the following equation:
Cd_Treg = Cd + (f2_TReg – f2)