# Commission Regulation (EU) 2017/1151 of 1 June 2017 supplementing Regulation (EC) No 715/2007 of the European Parliament and of the Council on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, amending Directive 2007/46/EC of the European Parliament and of the Council, Commission Regulation (EC) No 692/2008 and Commission Regulation (EU) No 1230/2012 and repealing Commission Regulation (EC) No 692/2008 (Text with EEA relevance), Division 3.4.1


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:
f2is the second order road load coefficient, at reference conditions, N/(km/h)2;
Trefis the road load reference temperature as specified in paragraph 3.2.10. of this Annex, C;
Tregis 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)

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/6a/division/division/3./division/3.4./division/3.4.1. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/6a/division/division-3./division-3.4./division-3.4.1.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.