# Regulation (EC) No 1222/2009 of the European Parliament and of the Council of 25 November 2009 on the labelling of tyres with respect to fuel efficiency and other essential parameters (Text with EEA relevance), Division 2: The wet grip class of C2 and C3 tyres must be determined on the basis of the wet grip index ( G ) according to the ‘A’ to ‘G’ scale specified in the table below, calculated in accordance with point (3) and measured in accordance with ISO 15222:2011 whereby the following Standard Reference Test Tyres (SRTT) must be used:

Extent: E+W+S+N.I.

(i) for C2 tyres, the SRTT 225/75 R 16 C, ASTM F 2872-11;
(ii) for C3 tyres having Nominal Section Width lower than 285 mm, the SRTT 245/70R19.5, ASTM F 2871-11;
(iii) for C3 tyres having Nominal Section Width greater than or equal to 285 mm, the SRTT 315/70R22.5, ASTM F 2870-11.

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Source: https://www.legislation.gov.uk/eur/2009/1222/annex/I/part/2/division/2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-1222/annex-I/part-2/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.