# 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 8.2.2: Downscaling procedure for Class 2 vehicles


Since the driveability problems are exclusively related to the extra high speed phases of the Class 2 and Class 3 cycles, the downscaling is related to those time periods of the extra high speed phases where driveability problems are expected to occur (see Figures A1/15 and A1/16).
Figure A1/15
Downscaled extra high speed phase of the class 2 WLTC
For the Class 2 cycle, the downscaling period is the time period between second 1520 and second 1742. Within this time period, the acceleration for the original cycle shall be calculated using the following equation:
aorigi=vi+ 1− vi3,6where:
viis the vehicle speed, km/h;
iis the time between second 1520 and second 1742.
The downscaling shall be applied first to the time period between second 1520 and second 1725. Second 1725 is the time when the maximum speed of the extra high speed phase is reached. The downscaled speed trace shall be subsequently calculated using the following equation:
vdsci+ 1=vdsci+ aorigi×1− fdsc× 3,6for i = 1520 to 1724.
For i = 1520, vdsci=vorigi
In order to meet the original vehicle speed at second 1743, a correction factor for the deceleration shall be calculated using the following equation:
fcorr_dec=vdsc_1725− 90,4vorig_1725− 90,490,4 km/h is the original vehicle speed at second 1743.
The downscaled vehicle speed between second 1726 and second 1742 shall be calculated using the following equation:
vdsci=vdsci− 1+ aorigi− 1× fcorr_dec× 3,6for i = 1726 to 1742.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/1/division/division/8./division/8.2./division/8.2.2. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/1/division/division-8./division-8.2./division-8.2.2.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.