{
  "url": "https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/4/division/division-4./division-4.3./division-4.3.2./division-4.3.2.4.",
  "json_url": "https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/4/division/division-4./division-4.3./division-4.3.2./division-4.3.2.4..json",
  "legislation": "eur/2017/1151",
  "legislation_title": "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)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2017-1151",
  "path": "annex/Sub/4/division/division/4./division/4.3./division/4.3.2./division/4.3.2.4.",
  "kind": "division",
  "number": "4.3.2.4",
  "heading": "Vehicle coastdown procedure",
  "text": "The measurements shall be carried out in opposite directions until a minimum of ten consecutive runs (five in each direction) have been obtained. Should an individual run fail to satisfy the required on-board anemometry test conditions, that run and the corresponding run in the opposite direction shall be rejected. All valid pairs shall be included in the final analysis with a minimum of 5 pairs of coastdown runs. See paragraph 4.3.2.6.10. of this Sub-Annex for statistical validation criteria.\nThe anemometer shall be installed in a position such that the effect on the operating characteristics of the vehicle is minimised.\nThe anemometer shall be installed according to one of the options below:\n(a)Using a boom approximately 2 metres in front of the vehicle’s forward aerodynamic stagnation point;\n(b)On the roof of the vehicle at its centreline. If possible, the anemometer shall be mounted within 30 cm from the top of the windshield.\n(c)On the engine compartment cover of the vehicle at its centreline, mounted at the midpoint position between the vehicle front and the base of the windshield.\nIn all cases, the anemometer shall be mounted parallel to the road surface. In the event that positions (b) or (c) are used, the coastdown results shall be analytically adjusted for the additional aerodynamic drag induced by the anemometer. The adjustment shall be made by testing the coastdown vehicle in a wind tunnel both with and without the anemometer installed in the same position as used on the track., The calculated difference shall be the incremental aerodynamic drag coefficient CD combined with the frontal area, which shall be used to correct the coastdown results.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/4/division/division/4./division/4.3./division/4.3.2./division/4.3.2.4.",
    "retrieved_at": "2026-11-01T14:44:48.753743+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}