# 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 6.6.3: Correcting measured chassis dynamometer forces to those on a flat surface


The measured forces on the chassis dynamometer shall be corrected to a reference equivalent to the road (flat surface) and the result shall be referred to as fj.
fj=fjDyno×c1×1RWheelRDyno×c2+1+fjDyno×1−c1
where:
c1is the tyre rolling resistance fraction of fjDyno;
c2is a chassis dynamometer-specific radius correction factor;
fjDynois the force calculated in paragraph 6.5.2.3.3. for each reference speed j, N;
RWheelis one-half of the nominal design tyre diameter, m;
RDynois the radius of the chassis dynamometer roller, m.
The manufacturer and the approval authority shall agree on the factors c1 and c2 to be used, based on correlation test evidence provided by the manufacturer for the range of tyre characteristics intended to be tested on the chassis dynamometer.
As an alternative the following conservative equation may be used:
fj=fjDyno×1RWheelRDyno×0,2+1
C2 shall be 0,2 except that 2,0 shall be used if the road load delta method (see paragraph 6.8.) is used and the road load delta calculated in accordance with paragraph 6.8.1. is negative.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/4/division/division/6./division/6.6./division/6.6.3. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/4/division/division-6./division-6.6./division-6.6.3.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.