Proposal to correct the code 19 rim diameter. The value of the rim diameter is calculated by multiplying the rim diameter code by 25.4 and rounding to the nearest integer. For the code 19 rim, the value should be 483 (482.6 rounded).

Proposal to modify the marking requirements to replace PSI with kilopascals (“kPa”). The intent is to harmonize the pressure indication and avoid confusion between UN Regulation No. 54 and US FMVSS 119 or FMVSS 139.

Proposal to change the measurement units for drum speed from min^-1 to km.h^-1 in alignment with the requirements with other tyre regulations. The proposed text also aligns wording in Annex 7, Appendix 1 with the text of the Regulation.

Proposal to amend the tyre dimension requirements. The current rules for calculating the dimensional limits are not consistent among the UN Regulations for tyres and within the Regulations themselves. Hence they lead to uncertainty in the correct calculation. The current proposal aims at unifying the calculation rules to those used in ISO 4000-1 and all major tyre standards, e.g. ETRTO, Tyre & Rim Association (T&RA), Japan Automobile Tyre Manufacturers Association (JATMA).

Proposal to:
a) Align definitions and content with the other tyre regulations (UN Regulations Nos. 30, 117, 75 etc.);
b) Include a definition of “manufacturer” extracted from the resolution “R.E.3”;
c) Adopt a common definition and use of the terms “Manufacturer’s name”, “Brand name”, “Trademark”, “Trade description” and “Commercial name” and their links; and
d) Add information in the certificate to enable approval authorities to more easily understand the products the certificate addresses.