SASO STANDARD   SASO  FDS /ECE 117 :2023  
السعودية للمواصفات و المقاييس و الجودة  
Saudi Standards, Metrology and Quality Org . (SASO)  
 
 
 
 
 
 
SASO  FDS /ECE 117 :2023  
 
 
 
الأحكام الموحدة المتعلقة بالموافقة على الإطارات فيما يتعلق بالانبعاثات الصوتية و/أو 
التماسك على الأسطح الرطبة و/أو مقاومة الدوران 
 Uniform provisions concerning the approval of tyres with regard to 
rolling sound emissions and/or to adhesion on wet surfaces and/or to 
rolling resistance  
 
 
 
 
 
 
 
 
 
 
ICS: 83.160.10  
 
SASO STANDARD   SASO  FDS /ECE 117 :2023  
 
مقدمة  
 
ﻗﺎﻤﺕ ﺍﻟﻬﻴﺌـﺔ ﺍﻟﺴـﻌﻭﺩﻴﺔ ﻟﻠﻤﻭﺍﺼـﻔﺎﺕ ﻭﺍﻟﻤﻘـﺎﻴﻴﺱ ﻭﺍﻟﺠـﻭﺩﺓ ﺒتحدﻴث اﻟمواﺼﻔﺔ ﺍﻟﺴـﻌﻭﺩﻴﺔ رﻗم SASO  ECE 
117:2015 الأحكﺎم اﻟموحدة اﻟمتﻌﻠﻘﺔ بﺎﻟموافﻘﺔ عﻠى الإطﺎرات فيمﺎ ﻴتﻌﻠق بﺎلانبﻌﺎثﺎت  اﻟصوتيﺔ و/أو اﻟتمﺎﺴك 
عﻠى الأﺴطح اﻟرطبﺔ و/أو ﻤﻘﺎوﻤﺔ اﻟدوران  و ذﻟك ﺒتبني اﻟلاﺌحﺔ اﻟﻔنيﺔ اﻟصﺎدرة عن اﻟﻠ جنﺔ الاﻗتصﺎديﺔ الأوروبيﺔ 
في الأﻤم اﻟمتحدة رﻗم  ECE 117:201 6  إﻟىECE 117:201 6/Amd7:2023   عﻠى أن تﻠغىاﻟمواﺼﻔﺔ  
اﻟسﻌوديﺔ رﻗم  SASO  ECE 117:2015  وتحل ﻤحﻠﻬﺎ . 
 
     Foreword   
  
Saudi Standards, Metrology and Quality Organization (SASO) has updated  the 
Saudi standard  No. SASO  ECE 117:2015  Uniform provisions concerning the 
approval of tyres with regard to rolling sou nd emissions and/or to adhesion on wet 
surfaces and/or to rolling resistance  by adopti on of the Technical regulation issued 
by the European Economic Commission at the United Nations  No. ECE 117:2016 
until ECE 117:2016/Am d7:2023. The approved Saudi standard  will replace and 
supersede the Saudi standard  No. SASO  ECE 117:2015 . 
 
  
  Agreement  
  Concerning the Adoption of Uniform Technical Prescriptions for 
Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be 
Used on Wheeled Vehicles and the Conditions for Reciprocal 
Recognition of Approvals Granted on the Basis of these Prescriptio ns* 
(Revision 2, including the amendments which entered into force on 16 October 1995)  
_________  
  Addendum 116 – Regulation No.  117 
  Revision 4 - Amendment  1 
Supplement 9 to the 02 series of amendments  – Date of entry into force: 9 February 2017  
  Uniform provisions concerning the approval of tyres with regard to 
rolling sound emissions and/or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. The authentic and legal binding text is:  
ECE/TRA NS/WP.29/2016 /60. 
_________  
 
UNITED NATIONS  
  
 * Former title of the Agreement: Agreement Concerning the Adoption of Uniform Conditions of 
Approval and Reciprocal Recognition of  Approval for Motor Vehicle Equipment and Parts, done at 
Geneva on  20 March  1958 .  E/ECE/324 /Rev.2/Add.11 6/Rev. 4/Amend. 1−E/ECE/TRANS/505 /Rev.2/Add.11 6/Rev. 4/Amend. 1 
   
 
22 February 2017  
 
E/ECE/324 /Rev.2/Add.11 6/Rev. 4/Amend. 1 
E/ECE/TRANS/505 /Rev.2/Add.11 6/Rev. 4/Amend. 1 
 
2 Paragraph 1.1., amend  to read:  
"1.1.  This Regulation applies to new pneumatic tyres * of Classes C1, C2 and C3 
with regard to their sound emissions, rolling resistance and to adhesion 
performance on wet surfaces (wet adhesion). It does not, however, apply to:  
                                                           
*  For the purpose of this Regulation  "tyres" means "pneumatic tyres"  
Paragraph 2.1., amend  to read:  
"2.1.  "Type of tyre " means  which do not differ in such essential characteristics as:  
(a) The manufacturer's name;  
(b) …." 
Add a new paragraph 2.2. to read:  
"2.2.  "Manufacturer " means the person or body who is responsible to the Type 
Approval Authority (TAA) for all aspects of the type -approval and for 
ensuring the conformity of production."  
Paragraph 2. 3., amend  to read:  
"2.3. "Brand name /trademark " means the identification of the brand or trademark  
as defined by the tyre manufacturer and marked on the sidewall(s) of the tyre. 
The Brand name/trademark may be the same as that of the  Manufacturer."  
Renumber paragraph 2.3. as 2.5.  
Add a new paragraph 2.4. to read:  
"2.4.  Trade description/commercial name: means an identification of a range of 
tyres as given by the tyre manufacturer. It may coincide with the brand 
name/trademark."  
Renumber 2.4. to 2.8. as paragraphs 2.6. to 2.10.  
Paragraph 2.9. (former) , amend  to read:  
"2.11 . "Reinforced tyre " or " extra -load tyre " of Class C1 means a tyre structure 
designed…"  
Renumber paragraphs 2.10. to 2.18. as paragraphs 2.12. to 2.20.  
Paragraph 3.1.2., amend  to read:  
"3.1.2.  Manufacturer's name;"  
Paragraph 3.1.5., amend  to read:  
"3.1.5.  Brand name(s )/trademark(s),  trade description(s )/commercial name(s) ;" 
Paragraph 3.5. , shall be deleted  
Paragraph 4.2.1., amend  to read:  
"4.2.1.  The manufacturer's name or the Brand name/ trademark;"  
Paragraph 4.2.2., amend  to read:  
"4.2.2.  The trade description /commercial name  (see paragraph 2. 4. of this 
Regulation). However, the trade description is not required when it coincides 
with the Brand name/ trademark;"  E/ECE/324/ Rev. 2/Add.11 6/Rev. 4/Amend. 1 
E/ECE/TRANS/505/ Rev. 2/Add.11 6/Rev. 4/Amend. 1 
 
3 Paragraph 7., amend  to read:  
"7. Modifications of the type of tyre and extension of 
approv al" 
Paragraph 10., amend  to read:  
"10. Production  definitively discontinued  
If the holder of an approval completely ceases to manufacture a type of tyre 
approved in accordance…"  
Add a number of a paragraph to the first alinea and amend to read:  
"11.1 . The Contracting Parties to the  1958  Agreement which apply this Regulation 
shall communicate to the United Nations Secretariat, the names and addresses 
of the Technical Services  responsible for conducting  approval tests  and, 
where applicable, of the approved te st laboratories   and of the Type Approval 
Authorities which grant approval and to which forms certifying approval or 
extension of approval or refusal  of approval  or withdrawal of approval, or 
production definitively discontinued,  issued in other countries, are to be 
sent."  
Add a new paragraph 11.2. to read:  
"11.2.  The Contracting Parties to the 1958 Agreement which apply this Regulation 
may designate laboratories of tyre manufacturers as approved test 
laboratories."  
Add a new par agraph 11.3. to read:  
"11.3.  Where a Contracting Party to the 1958 Agreement applies paragraph 11.2. 
Above, it may, if it so desires, be represented at the tests by one or more 
persons of its choice."  
Annex 1,  
Item 1. amend  to read:  
"1. Manufacturer's name  and address:"  
Item 4. amend  to read:  
"4. Tyre type designation:  
4.1. Brand  name(s)/trademark(s) of the type of tyre:  
4.2. Trade description(s)/ Commercial name(s) of the type of tyre:"  
Item 5. amend  to read:  
"5. Technical service and, where applicable, test laboratory approved for purposes of 
approval or of verification of conformity tests:"  E/ECE/324 /Rev.2/Add.11 6/Rev. 4/Amend. 1 
E/ECE/TRANS/505 /Rev.2/Add.11 6/Rev. 4/Amend. 1 
 
4 Item 14.2. amend  to read:  
"14.2.  A list of tyre size designations: Specify for each brand name /trademark  and/or each  
trade description/  Commercial name the list of tyre size designations, adding…"  
Annex 2,  
Appendix 1, Example 1 , amend to read:  
"The above approval mark, affixed to a tyre shows that a tyre concerned…"  
Annex 3,  
Paragraph 2.5.3. , amend to read:  
"2.5.3.  Tyre inflation pressure  
Each tyre  fitted on the test vehicle shall have a test pressure P t not higher than 
the reference pressure P r and within the interval:  
𝑃𝑟∙(𝑄𝑡
𝑄𝑟)1.25
≤𝑃𝑡≤1.1∙𝑃𝑟∙(𝑄𝑡
𝑄𝑟)1.25
 
For Class C2 and Class C3 the reference pressure P r is the inflation pressure 
corresponding to the pressure in kPa or to the pressure index marked on the 
sidewall.    
For Class C1 the reference pressure is P r = 250 kPa for "standard" tyres 
and 290 kPa for "reinforced" or "extra load" tyres; the minimum test  pressure 
shall be P t = 150 kPa."  
      
 
GE.20-01317 (E) 

  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nations Regulations * 
(Revision 3, including the ame ndments which entered into force on 14 September 2017)  
_________  
  Addendum 116 – UN Regulation No.  117 
  Revision 4 - Amendment  2 
Supplement 10 to the 02 series of amendments  – Date of entry into force: 11 January 2020  
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. The authentic and legal binding text is:  
ECE/TRANS/WP. 29/201 9/54. 
_________  
UNITED NATIONS  
  
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical P rescriptions for Wheeled Vehicles, 
Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision  2).  E/ECE/324 /Rev.2/Add.116/Rev.4/Amend.2 −E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend.2  
   
 
29 January  2020 
E/ECE/324 /Rev.2/Add.116/Rev.4/Amend.2  
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend.2  
 
2 Paragraph 2.1., amend  to read:  
"2.1.  "Type of tyre " means  tyres  which do not differ in such essential characteristics 
as:"  
Paragraph 5. and its subparagraphs,  amend to read:  
"5. Approval  
5.1. If the representative tyre size of the type of tyre submitted for approval 
pursuant to this Regulation meets the requirements of paragraphs  6. and  7. 
below, approval of that type of tyre shall be granted.  
5.2. An approval number according to Schedule 4 to the Revision 3 of the 1958 
Agreement shall be assigned to the type of tyre approved. The same 
Contracting Party may not assign the same number to another type of tyre.  
5.2.1.  Instead of granting the original type approval number pursuant to UN 
Regulation No. 117, upon the reque st of the manufacturer, the Type Approval 
Authority may grant the type approval number, which had been granted before 
to that type of tyre pursuant to UN Regulations Nos.  30 or 54 with the 
subsequent extension number.  
5.2.2.  The communication form mentioned in paragraph 5.3. below shall identify 
specific performance parameters of UN Regulation No. 117 by the following 
suffixes:  
S To identify additional conformity to the requirements on tyre rolling 
sound emissions;  
W To identify additional conformit y to the requirements on tyre adhesion 
on wet surfaces;  
R To identify additional conformity to the requirements on tyre rolling 
resistance.  
 Taking into account that two stages are defined for rolling sound and rolling 
resistance specifications in paragrap hs 6.1. and 6.3. below, S and R will be 
followed either by the suffix "1" for compliance to stage 1 or by the suffix "2" 
for compliance to stage 2.  
5.3. Notice of approval or extension of approval or refusal of approval of a type of 
tyre pursuant to this R egulation shall be communicated to the Parties to the 
Agreement, which apply this Regulation by means of a form conforming to the 
model in Annex  1 to the Regulation.  
5.3.1.  With reference to paragraph 5.2.1. above, ty re manufacturers are entitled to 
submit  an application for extension of type approval to the requirements of 
other Regulations relevant to the tyre type. In that case, a copy of the relevant 
type approval communication(s), as issued by the relevant Type Approval 
Authority, shall be attached to the application for extension of approval. All 
applications for extension of approval(s) shall only be granted by the Type 
Approval Authority which issued the original approval for the tyre.  
5.3.1.1.  When extension of approval is granted to incorporate int o the communication 
form (see Annex  1 to this Regulation) certification(s) of conformity to other 
Regulations, (all) the specific type approval number(s) and the Regulation 
itself shall be added to item  9. of Annex 1  "Communication form ". E/ECE/324/ Rev.2/Add.116/Rev.4/Amend.2  
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend.2  
 
3 5.3.1.2.  The suff ix(es) mentioned in paragraph 5.2.2. above shall be preceded by the 
two digits identifying the series of amendments of the prescription on tyre 
performances for UN Regulation No. 117, e.g. 02S2 to identify the second 
series of amendments on tyre road rolli ng sound emissions at stage  2 or 
02S1WR1 to identify the second series of amendments on tyre road rolling 
sound emissions at stage 1, tyre adhesion on wet surfaces and rolling resistance 
at stage  1 (see paragraph 6.1. below for stage 1 and stage 2 definiti ons).  
5.4. In the space referred to in paragraph  4.3. and in accordance with the 
requirements of paragraph  4.4. above  there shall be affixed to every tyre size, 
conforming to the type of tyre approved under this Regulation, an international 
approval mark c onsisting of:  
5.4.1.  A circle surrounding the letter "E" followed by the distinguishing number of 
the country which has granted approval ;12 and 
5.4.2.  The part of the approval number specified in paragraph 3 Section 3 of Schedule 
4 to the Revision 3 of the  1958 Agreement, which shall be placed close to the 
circle prescribed in paragraph  5.4.1. above either above or below the "E" or to 
the left or right of that letter.  
5.4.3.  ... " 
(Footnote 12 remains unchanged).  
Annex 1  "Communication ", introductory part, amend to read:  
"Annex 1  
  Communication  
(Maximum format: A4 (210 x 297 mm))  
 Issued by:  Name of administration:  
......................................  
......................................  
......................................  
11 
Concerning :2  Approval  granted  
    Approval extended  
    Approval refused  
    Approval withdrawn  
    Production definitively discontinued  
of a type of tyre with regard to "rolling sound emission level " and/or "adhesion performance 
on wet surfaces"  and/or "rolling resistance" pu rsuant to UN Regulation No.  117 
Approval No3.......................                       Suffix(es)4 .......................  
1. …  
… 
_________________________  
 1 Distinguishing number of the country which has granted/extended/refused/withdrawn approval (see 
approval provisions in this Regulation).  
 2 Strike out what does not apply.  
 3 According to Schedule 4 to Revision 3 of the 1958 Agreement.  
 4 According to para graphs 5.2.2. and 5.3.1.2. of this Regulation."  
E/ECE/324 /Rev.2/Add.116/Rev.4/Amend.2  
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend.2  
 
4 Annex 7 , Appendix 2, Part 2, paragraph 5.,  amend to read:  
"5. Test results: mean fully developed decelerations (m/s²) / traction coefficient1 
Run number  Specification  SRTT  
(1st test)  Candidate  Candidate  SRTT  
(2nd test)  
1      
2      
3      
4      
5      
6      
      
      
      
Mean       
Std-deviation       
CV (%)  < 6 %      
Validation 
SRTT  (SRTT) ≤ 5 %     
SRTT 
average       
Snow grip 
index   1.00    
" 
     
 
  
 1 Strike out what does not apply.   
  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nations Regulations * 
(Revision 3, including the amendments which entered into force on 14 Septembe r 2017)  
_________  
  Addendum 116 – UN Regulation No.  117 
  Revision 4 - Amendment  3 
Supplement 11 to the 02 series of amendments  – Date of entry into force: 25 September  2020  
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. The authentic and legal binding text is:  
ECE/TRANS/WP.29/20 20/6 (as amended by paragraph 85 of the report 
ECE/TRANS/WP.29/1151) . 
_________  
UNITED NATIONS  
  
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, 
Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision 2).   E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3−E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
   
 
4 November  2020 
E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
2 Paragraph 2.1.,  amend to read:  
"2.1.  "Type of tyre " means tyres which do not differ in such essential characteristics 
as: 
(a) The manufacturer's name;  
(b) The tyre class (see paragraph 2.4. below);  
(c) The tyre structure;  
(d) The category of use: normal tyre, snow tyre and special use tyre;  
(e) Whether tyre for use in severe snow conditions or not;  
(f) For Classes C2 and C3 tyres, wh ether traction tyre or not;  
(g) The tread pattern (see paragraph  3.2.1. of this Regulation)."  
Paragraph 2.18.,  amend to read:  
"2.18.  "Standard Reference Test Tyre (SRTT) " means a tyre that is produced, 
controlled and stored in accordance with the American Society for Testing and 
Materials (ASTM) standards  
(a) E1136 – 17 for the size P195/75R14 and referred to as “SRTT14”,  
(b) F2872 – 16 for the size 225/75R16C and referred to as “SRTT16C”,  
(c) F2871 – 16 for the size 245/70R19.5 and referred to as “SRTT19.5”,  
(d) F2870 – 16 for the size 315/70R22.5 and referred to as “SRTT22.5”,  
(e) F2493 – 18 for the size P225/60R16 and referred to as “SRTT16”."  
Paragraph 2.19.1.,  amend to read:  
"2.19.1.  "Adhesion on wet surfaces " means the relative braking perform ance, on a wet 
surface, of a test vehicle equipped with the candidate tyre in comparison to that 
of the same test vehicle equipped with a Standard Reference Test Tyre 
(SRTT). " 
Paragraph 2.20.1.,  amend to read:  
"2.20.1.  "Rolling resistance F r"  means the lo ss of energy (or energy consumed) per unit 
of distance travelled.³ " 
Paragraph 2.20.3.,  amend to read:  
"2.20.3.  "New test tyre " means a tyre which has not been previously used in a rolling 
deflected test which elevates the tyre’s temperature to higher than that 
generated in rolling resistance tests, and which has not previously been 
exposed to a temperature above 40 °C.5,6" 
Paragraph 2.20.5.,  amend to read:  
"2.20.5.  "Capped inflation " means the process of inflating the tyre to the required cold 
inflation pressure and allowing the inflation pressure to build up, as the tyre is 
warmed up while running. " 
Paragraph 2.20.8.,  amend to read:  
"2.20.8.  "Inertia " or " moment of  inertia " means the ratio of the torque applied to a 
rotating body, such as a tyre assembly or machine drum, to the rotational 
acceleration of this body.8" 
Paragraphs 3.1.2. to 3.1.10.,  amend to read and renumber:  
"3.1.2.  Manufacturer’s name and address;  
3.1.3.  If applicable, name and address of manufacturer's representative;  
3.1.4.  Tyre class (Class C1, C2 or C3) (see paragraph 2.6. of this Regulation);  E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
3 3.1.5.  Category of use (normal, snow, or special);  
3.1.5.1.  Whether tyre for use in severe snow conditions or not;  
3.1.5.2.  For Class C2 and C3 tyres, whether traction tyre or not;  
3.1.6.  Tyre structure;  
3.1.7.  Brand name(s)/trademark(s), trade description(s)/commercial name(s);  
3.1.8.  A list of tyre size designations covered by this application and specifying for 
each brand name/trademark and/or each trade description/commercial name 
the applicable tyre size designations and service descriptions, adding in case 
of Class C1 tyres whether "reinforced" (or "extra load") or not."  
Paragraph 3.4.,  amend to read:  
"3.4. With regard to the application, testing may be confined to a representative tyre 
size of the type of tyre, at the discretion of the Type Approval Authority. " 
Paragraph 6.2.,  amend to read:  
"6.2. The wet grip performance will be based on a procedure that compare s either 
peak brake force coefficient ("pbfc") or mean fully developed deceleration 
("mfdd") against values achieved by a Standard Reference Test Tyre (SRTT). 
The relative performance shall be indicated by a wet grip index  (G)." 
Paragraph 6.4.,  amend to re ad: 
"6.4. In order to be classified as a "snow tyre for use in severe snow conditions" the tyre 
shall meet the performance requirements of paragraph 6.4.1. below. The tyre shall 
meet these requirements based on a test method of Annex 7 by which:  
 (a) The mean fully developed deceleration ("mfdd") in a braking test;  
(b) Or alternatively an average traction force in a traction test;  
(c) Or alternatively the average acceleration in an acceleration test  
 of the candidate tyre is compared to that of a Stan dard Reference Test Tyre 
(SRTT).  
The relative performance shall be indicated by a snow grip index."  
Paragraph 6.4.1.1.,  amend to read:  
"6.4.1.1.  Class C1, C2 and C3 tyres  
 The minimum snow grip index value, as calculated in the procedure described 
in Annex  7 and compared with the respective Standard Reference Test Tyre 
(SRTT) shall be as follows:  
Class  
of tyre  Snow grip index  
(brake on snow method) (a) Snow grip index  
(spin traction method) 
(b) Snow grip index  
(acceleration method) (c) 
 Ref. = SRTT14  Ref.= SRTT16C  Ref. = SRTT14  Ref.s = SRTT19.5, 
SRTT22.5  
C1  1.07 No 1.10 No 
C2 No 1.02 1.10 No 
C3 No No No 1.25 
  (a) See paragraph 3. of Annex 7 to this Regulation  
  (b) See paragraph 2. of Annex 7 to this Regulation  
  (c) See paragraph 4. of Annex 7 to this Regulation " E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
4 Insert a new paragraph 12.9. to read:  
"12.9.  Until 3 months after the date of entry into force of Supplement 11 to the 02 
series of amendments to this Regulation, Contracting Parties applying this 
Regulation can continue to gran t type approvals according to the 02 series of 
amendments to this Regulation, without taking into account the provisions of 
Supplement 11."  
Annex 1  
Item 3., amend to read:  
"… 
3. "Tyre class" of the type of tyre:  ................................ ................................ ...................  " 
Items 3.1. and 3.2. , renumber to 4.1. and  4.2. 
Insert  new items 4. and 5. to read:   
"4. "Category of use" of the type of tyre:  ................................ ................................ ..........   
4.1. Snow tyre for use in severe snow conditions (Yes/No)2 
4.2. Traction tyre (Yes/No)2 
5. Tyre structure:  ................................ ................................ ................................ ..............  " 
Items 4. to 14.2., renumber as 6. to 16.2., respectively.   
Items 8.1. to 8.4. (new), amend to read:  
"8.1. Sound level of the representative tyre size, see paragraph  2.7. of this Regulation, 
as per item  7. of the test report in Appendix 1 to Annex  3: ................ dB(A) a t 
reference speed of  70/80  km/h2 
8.2. Wet adhesion level of the representative tyre size, see paragraph 2.7.  of this 
Regulation, as per item  7. of the test report in the appendix to Annex  5: 
……………………… (G) using the vehicle or trailer method2 
8.3. Rolling r esistance level of the representative tyre size, see paragraph 2.7.  of this 
Regulation, as per item 7. of the test report in Appendix 1 to Annex  6 ................   
8.4. Snow grip level of the representative tyre size, see paragraph 2.7.  of Regulation 
No. 117, as per item 7. of the test report in the appendix3 to 
Annex  7:………………. (Snow grip index) using the brake on snow method2, 
spin traction method2 or acceleration method.2" 
Item 16.2. (new), amend to read:  
"16.2.  A list of tyre size designations: Specify for each brand na me/trademark and/or 
each trade description/Commercial name the list of tyre size designations and 
service descriptions, adding in case of Class C1 tyres whether "reinforced" 
(or "extra load") or not. " 
Annex 2  
Appendix 2, example 2, figure, amend to read:  
" 
 
 0212345 S2 0236378   
E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
5 " 
Annex 3  
Paragraph 1.1., amend to read:  
"1.1. Acoustic measurements  
The sound level meter or the equivalent measuring system, including the 
windscreen recommended by the manufacturer shall meet or exceed the 
requirements of Type  1 instruments in accordance with IEC  61672 -1:2013. " 
Paragraph 1.1.1., amend to read:  
"1.1.1.  Calibration  
 At the beginning and at the end of every measurement session, the entire 
measurement system shall be checked b y means of a sound calibrator that 
fulfils the requirements for sound calibrators of at least precision Class 1 
according to IEC 60942:2017. Without any further adjustment the difference 
between the readings of two consecutive checks shall be less than or equal to 
0.5 dB(A). If this value is exceeded, the results of the measurements obtained 
after the previous satisfactory check shall be discarded. " 
Paragraph 4.3 ., renumber as 4.2. and amend to read:   
"4.2. Temperature correction  
 For Class C1 and Class C2 tyres, the rolling sound levels Li(i) obtained at the 
test surface temperature i (where i denotes the number of the single 
measurement) shall be normalized to a test surface reference temperature ref 
by applying a temperature c orrection,  according to the following formula:  
𝐿𝑖(𝜗ref)=𝐿𝑖(𝜗𝑖)+𝐾(𝜗ref−𝜗𝑖) 
where:  
 ref = 20 °C,  
 For Class C1 tyres, the coefficient K is: 
− 0.03 dB(A)/°C  when i > ref and 
− 0.06 dB(A)/°C  when i < ref. 
 For Class C2 tyres, the coefficient K is − 0.02 dB(A)/°C . 
 Notwithstanding the above procedure, the temperature correction may be made 
only on the final reported tyre rolling sound level LR, utilizing the arithmetic 
mean value of the measured temperatures,  if the measured test surface 
temperature does not change more than  5 °C within all measurements 
necessary for the determination of the sound level of one set of tyres. In this 
case the regression analysis below shall be based on the uncorrected rolling 
sound levels Li(i). 
 There will be no temperature correction for Class C3 tyres. " 
Paragraph 4.2. (former) , renumber as 4.3. and amend to read:   
"4.3. Regression analysis of rolling sound measurements  
 The tyre -road rolling sound level LR(ref) in dB(A) is determined by a 
regression analysis according to:  
𝐿𝑅(𝜗ref)=𝐿̅−𝑎∙𝜏̅  Or  
 
 0212345 S2WR2  
0236378   
E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
6 where:  
𝐿̅  is the mean value of the temperature -corrected rolling sound 
levels Li(ref), measured in  dB(A):  
  
𝐿̅=1
𝑛∑𝐿𝑖(𝜗ref)𝑛
𝑖=1 
   
n  is the number of measurements ( n ≥ 16),  
𝜏̅   is the mean value of logarithms of speeds Vi: 
  𝜏̅=1
𝑛∑ 𝜏𝑖𝑛
𝑖=1   with   𝜏𝑖=log 10(𝑉𝑖
𝑉ref) 
a  is the slope of the regression line in dB(A):  
  𝑎=∑ [(𝜏𝑖−𝜏̅)(𝐿𝑖(𝜗ref)−𝐿̅)]𝑛
𝑖=1
∑ (𝜏𝑖−𝜏̅)2 𝑛
𝑖=1 
" 
Paragraph 4.4 ., amend to read:   
"4.4. In order to take account of any measuring instrument inaccuracies, the 
temperature corrected tyre rolling sound level LR(ref) in dB(A) shall be 
reduced by 1  dB(A) and then rounded down to the nearest lower whole value 
to obtain the final result. " 
Paragraph 4.5 . shall be delete d.  
Annex 3 - Appendix 1, amend to read:  
"… 
Part 1 – Report  
… 
2. Name and address of manufacturer:  ................................ ................................ .............   
… 
4. Brand name and trade description:  ................................ ................................ ...............   
… 
6. Category of use:  ................................ ................................ ................................ ...........   
6.1. Tyre for use in severe snow conditions (Yes/No)1 
6.2. Traction tyre (Yes/No)1 
7. Sound level according to paragraph 4.4. of Annex  3:  ................................ ......  dB(A)  
 at reference speed of 70/80 km/h1  
… 
Part 2 – Test data  
… 
4.3. Reference (test) inflation pressure2:  ................................ ................................ .....  kPa 
… 
5. Valid test results:  ................................ ................................ ................................ ..........   E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
7 Run 
No. Test 
speed  
km/h  Direction 
of run  Sound level lefta 
measured dB(A)  Sound level 
righta 
measured  
dB(A)  Air temp.  
oC Test surface 
temp.  
oC Sound level lefta 
temp. correctedb 
dB(A)  Sound level righta 
temp. correctedb 
dB(A)  Comments  
1          
2          
3          
4          
5          
6          
7          
8          
a Relative to the vehicle.  
b Omit, if regression according to paragraph 4.3. of Annex 3 is made on the uncorrected rolling sound level values.  
5.1. Regression line slope:  ................................ ................................ ................................ ..  
5.2. Sound level according to paragraph 4.3. of Annex 3:  
   dB(A)"  
Annex 3 - Appendix 1, add a new footnote 2:  
"2 for C2 and C3 tyres, corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation " 
Annex 5, part A  
Paragraphs 1.4 and 1.5.,  delete.  
Paragraph 2.4.,  amend to read:  
"2.4.  "Reference tyre(s) (R)" means a tyre or a tyre set of Standard Reference Test 
Tyres SRTT16."  
Paragraphs 2.12. and 2.13.  shall be  delete d.  
Paragraph 3.2.2.,  amend to read:  
"3.2.2.  Standard  Reference Test Tyre method  
This method uses the Standard Reference Test Tyre SRTT14.  
Perform at least six (6) valid measurements of the peak braking force 
coefficient with the SRTT14 using the trailer towed by a vehicle or a tyre test 
vehicle test procedure as specified in clause 4.2. (at 65 km/h and 180  kPa).  
The average  (µpeak,ave ) of the measured peak braking force coefficients shall be 
corrected for the effects of temperature as follows:  
𝜇peak,corr =𝜇peak,ave +0.0035 ∙(𝑡−20) 
where t is the wetted road surface temperature in degrees Celsius.  
The temperature corrected ave rage peak braking force coefficient  (µpeak,corr ) 
shall be 0.7 ± 0.1."  
Paragraph 4.1.6.2., first sentence,  amend to read:   
" The AD coefficient of variation CV AD is calculated as follows:  
𝐶𝑉𝐴𝐷=100% ∙𝜎𝐴𝐷
𝐴𝐷̅̅̅̅ E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
8 where  
𝜎𝐴𝐷=√1
𝑁−1∑ (𝐴𝐷 𝑖−𝐴𝐷̅̅̅̅)2 𝑁
𝑖=1  denotes the corrected sample standard 
deviation and  
𝐴𝐷̅̅̅̅ the arithmetic mean of the Average Decelerations ( 𝐴𝐷 𝑖) of N test runs. " 
Paragraph 4.1.7.3.,  amend to read:  
"4.1.7.3.  Storage and preservation  
It is necessary that all the tyres of a control tyre  set have been stored in the 
same conditions . As soon as the control tyre set has been tested in comparison 
with the reference tyre, the specific storage conditions defined in ASTM E1136 
– 17 shall be applied."  
Paragraph 4.2.8.2., first sentence,  amend to read:  
" The µpeak coefficient of variation CV µ is calculated as follows:  
𝐶𝑉𝜇=100% ∙𝜎𝜇
𝜇peak̅̅̅̅̅̅ 
where  
𝜎µ=√1
𝑁−1∑ (𝜇peak ,𝑖−𝜇peak̅̅̅̅̅̅)2𝑁
𝑖=1  denotes the corrected sample standard 
deviation and  
𝜇peak̅̅̅̅̅̅ the arithmetic mean of the peak braking force coefficients ( 𝜇peak ,𝑖) of N 
test runs. " 
Annex 5, part B  
Paragraph 1.1.1.,  amend to read:  
"1.1.1.  Standard Reference Test Tyre (SRTT) method  
This method uses the Standard Reference Test Tyre SRTT14.  
Perform at least six (6) valid measurements of the peak braking force 
coefficients with the Standard Reference Test Tyre SRTT14 using the trailer 
or special purpose tyre evaluation vehicle test procedure as specified in clause 
2.1. (at 65 km/h and 180  kPa). 
The average ( µpeak,ave ) of the measured peak braking force coefficients shall be 
corrected for the effects of temperature as follows:  
𝜇peak,corr =𝜇peak,ave +0.0035 ∙(𝑡−20) 
where t is the wetted track surface temperature in degrees Celsius.  
The temperature  corrected average peak braking force coefficient  (µpeak,corr ) 
shall be 0.7 ± 0.1.  
The test shall be conducted using the lanes and length of the track to be used 
for the wet grip test.  
For the trailer method, testing is run in such a way that braking occur s within 
10 meters distance of where the surface was characterized."  
Paragraph 1.4.,  amend to read:  
"1.4. In order to cover the range of the tyre sizes fitting the commercial vehicles, the  
Standard Reference Test Tyre s (SRTT) shall be used to measure the relative 
wet index as shown in the following table:  
For C3 tyres  
Narrow family  Wide family  E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
9 SNominal  < 285 mm  SNominal  > 285 mm  
SRTT19.5  SRTT22.5  
For C2 tyres  
SRTT16C  
SNominal = Tyre nominal section width  
" 
Paragraph 2.1.2.1.,  amend to read:  
"2.1.2.1.  …  
Pr = Inflation pressure corresponding to the the indication of the inflation 
pressure marked on the sidewall  as required by paragraph 4.1. of this 
Regulation.… " 
Paragraph 2.1.2.12.,  amend to read:  
"2.1.2.12 . …  
Analogue signals should be filtered to remove noise. … " 
Paragraph 2.1.2.13.,  amend to read:  
"2.1.2.13.  …   
For the reference tyre:  
If the coefficient of variation of the peak braking coefficient CV µ of the 
reference tyre, which is calculated by the formula given in 4.2.8.2. of part (A) 
of this Annex, is higher than five per cent, discard all data and repeat the test 
for this reference  tyre.  
For the candidate tyres:  
The coefficients of variation CV µ are calculated for all the candidate tyres 
according to the formula in 4.2.8.2. of part (A) of this Annex. If one coefficient 
of variation is greater than five per cent, discard the data fo r this candidate tyre 
and repeat the test. … " 
Paragraph 2.2.2.3.,  amend to read:  
"2.2.2.3.  …  
Pr = Inflation pressure corresponding to the indication of the inflation pressure 
marked on the sidewall  as required by paragraph 4.1. of this Regulation.  
… 
Pr = Inflation pressure corresponding to the indication of the inflation 
pressure marked on the sidewall as required by paragraph 4.1. of this 
Regulation.  
Check the tyre pressure just prior to testing at  ambient temperature. " 
Paragraph 2.2.2.8.1.,  amend to read:  
"2.2.2.8.1.  …  
All conditions are in conformity with paragraphs 2.2.1. to 2.2.2.5. above. " E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
10 Annex 5 – Appendix, Example 1 , amend to read:  
"… 
No. 1 2 3 4 5 6 7 8 9 10 
Size           
Service description            
Reference (test) inflation 
pressure(1) (kPa)            
Tyre identification            
…           
Wet Grip Index            
Surface temp. (°C)            
…           
… 
(1) for C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation " 
Annex 5 – Appendix, Example 2 , amend to read:  
"… 
No. 1 2 3 4 5 
Brand name  Uniroyal  TYRE B  TYRE C  TYRE D  Uniroyal  
Pattern/Trade description  ASTM F 2493 
SRTT16  PATTERN B  PATTERN C  PATTERN D  ASTM F 2493 
SRTT16  
Size P225/60R16  SIZE B  SIZE C  SIZE D  P225/60R16  
Service description  97S LI/SS  LI/SS  LI/SS  97S 
Reference (test) inflation 
pressure(1) (kPa)       
Tyre identification  XXXXXXXXX  YYYYYYYYY  ZZZZZZZZZ  NNNNNNNNN  XXXXXXXXX  
… 
(1) for C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation " 
Annex 6  
Paragraph 2.2.,  amend to read:  
"2.2. Measuring rim  
The tyre shall be mounted on a steel or light alloy measuring rim, as follows:  
(a) For Class C1 tyres, the width of the rim shall be as defined in ISO  4000 -
1:2015,  
(b) For Class C2 and C3 tyres, the width of the rim shall be as defined in 
ISO 4209  1:2001.  
In cases where the width is not defined in the above mentioned ISO Standards, 
the rim width as defined by one of the standards organizations as specified in 
Appendix 4 may be used. " 
Paragraph 2.4.3.  shall be  delete d. 
Paragraph 3.1 ., amend to read:  
"3.1. General  E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
11  The test consists of a measurement of rolling resistance in which the tyre is 
inflated to the required cold inflation pressure and the inflation pressure 
allowed to build up, i.e., "capped inflation".  
Paragra ph 3.2,  amend to read:  
"3.2. Test speeds  
 The rolling resistance coefficient value shall be obtained at the appropriate 
drum speed specified in Table  1." 
Table 1,  amend to read:  
"Table 1  
Test Speeds (in km/h)  
Tyre Class  C1 C2 and C3  C3 
Load index  All LI ≤ 121  LI > 121  
Speed symbol  All All J (100 km/h ) and lower  K (110 km/h ) 
and higher  
Test speed 
(km/h)  80 80 60 80 
" 
Table 2,  amend to read:  
"Table 2  
Test loads and inflation pressures  
Tyre Class  C1 C2, C3  
 Standard 
load Reinforced or extra load   
Load  
% of maximum load 
capacity as indicated 
by the load capacity 
index   
80  
80  
85 
(refer to single application)  
Inflation pressure  
kPa  
210  
250  
Test inflation pressure corresponding 
to the indication of the inflation 
pressure marked on the sidewall as 
required by paragraph 4.1. of this 
Regulation.  
Note : The inflation pressure shall be capped with the accuracy specified in paragraph  4. of 
 Appendix  1 to this annex.  
" 
Paragraph 4.6.2.,  amend to read:  
"4.6.2.  Deceleration method  
  The deceleration method follows the procedure below:  
(a) Remove the tyre from the test surface while running at a speed greater 
than test speed;  
(b) Record the deceleration of the test drum D0/t and that of the 
unloaded tyre T0/t or record the decelerati on of the test drum j D0 and E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
12 that of the unloaded tyre j T0 in exact or approximate form in accordance 
with paragraph  3.5. above.  
  The speed range for measurement includes the test speed and does not exceed 
10 km/h above and 10 km/h below the test speed. " 
Paragraph 5.1.5.,  amend to read:  
"5.1.5.  Deceleration method  
 Calculate the parasitic losses Fpl, in newton.  
𝐹pl=𝐼𝐷
𝑅(∆𝜔D0
∆𝑡0)+𝐼𝑇
𝑅𝑟(∆𝜔T0
∆𝑡0) 
  where: …  
 
ΔD0  is the test drum angular speed increment, drum without tyre, in 
radians per second,  
   
ΔT0  is the tyre angular speed increment, unloaded tyre, in radian per 
second. …"  
Paragraph 5.2.1.,  amend to read:  
"5.2.1.  General  
 The rolling resistance Fr, expressed in newton, is calculated using the values 
obtained by testing the tyre to the conditions specified in this Regulation and 
by subtracting the appropriate parasitic losses Fpl, obtained according to 
paragraph  5.1. above. " 
Paragraph 6.4,  amend to read:  
"6.4. Measurement result  
 Where n measurements are greater than 1, if required by paragraph  4.6. above, 
the measurement result shall be the average of the Cr values obtained for the n 
measurements, after the corrections described in paragraphs  6.2. and 6.3. 
above have been made. Following this method, final Cr results shall be 
expressed in N/kN and rounded to the first decimal place according to 
ISO 80000 -1:2009, B.3, rule B. " 
Annex 6 - Appendix 1  
Paragraph 1, amend to read:  
"1. Purpose  
 The limits specified in this appendix a re necessary, but may not be sufficient, 
in order to achieve suitable levels of repeatable test results, which can also be 
correlated among various test laboratories. " 
"2.2. Run-out 
 In case vehicle rims are used, the run -out shall meet the following criteria:  
 (i)  for C1 tyres, C2 tyres and for C3 tyres with LI ≤ 121:  
  (a) Maximum radial run -out: 0.5 mm,  
  (b) Maximum lateral run -out: 0.5 mm;  
 (ii)  for C3 tyres with LI ≥ 122:  
  (a) Maximum radial run -out: 2.0 mm,  
  (b) Maximum lateral run -out: 2.0 mm. " E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
13 Paragraph 3.1.,  amend to read:  
"3.1. Load application  
 The direction of tyre loading application shall be kept normal to the test surface 
and sh all pass through the wheel centre within:  
 (a) 1 mrad for the force method;  
 (b) 5 mrad for the torque, power and deceleration methods. " 
Paragraph 4.(a) , amend to read:  
"(a) Tyre loading:  
(i) For C1 tyres, C2 tyres and for C3 tyres with LI ≤ 121: ±20 N or 
±0.5 per cent, whichever is greater;  
(ii) For C3 tyres with LI ≥ 122 : ±45 N or ±0.5 per cent whichever is 
greater; " 
Paragraph 5., amend to read:  
"… 
Parameter  C1 tyres, C2 tyres and C3 tyres with 
LI ≤ 121 C3 tyres with LI ≥ 122  
Tyre load  ±10 N or  ±0.5 % (a) ±30 N or ±0.5  % (a) 
…" 
Paragraph 7. , amend to read:  
"7. Test surface roughness  
 The roughness, measured laterally, of the new smooth steel drum surface shall 
have a maximum centreline average height value of 6.3  m. This value should 
be reconfirmed in case visible damage should occur. … " 
Annex 6 - Appendix 2, amend to read:  
"Annex 6 - Appendix 2  
(omitted) " 
Annex 6 - Appendix 3, amend to read and add a footnote (1) : 
"… 
Part1: Report  
… 
2. Name and address of manufacturer:  ................................ ................................ .............   
… 
4. Brand name and trade description:  ................................ ................................ ...............   
… 
6. Category of use:  ................................ ................................ ................................ ...........   
6.1. Tyre for use in severe snow conditions (Yes/No)2 ................................ ........................   
Part 2: Test data  
… 
3.3. Reference (test) inflation pressure(1):  ................................ ................................ .. kPa 
  (1) for C2 and C3 tyres, cor responding to the indication of the inflation pressure marked on the 
sidewall as required by paragraph 4.1. of this Regulation as indicated on the sidewall.  " E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
14 Annex 7  
Paragraph 3.4.1.1., amend to read:  
"3.4.1.1.  For each tyre and each braking test, the arithmetic mean 𝑎̅ and corrected 
sample standard deviation 𝜎𝑎 of the mfdd shall be computed and reported.  
 The coefficient of variation CV a of a tyre braking test shall be computed as:  
𝐶𝑉𝑎=100% ∙𝜎𝑎
𝑎̅ 
with 
𝜎𝑎=√1
𝑁−1∑(𝑎𝑖−𝑎̅)2𝑁
𝑖=1 
" 
Paragraph 3.4.1.2., amend to read:  
"3.4.1.2  Weighted averages waSRTT of two successive tests of the SRTT shall be 
computed taking into account the number of candidate tyres in between:  
 In the case of the order of testing R1 – T – R2, the weighted average of the 
SRTT to be used in the comparison of the performance of the candidate tyre 
shall be taken to be:  
𝑤𝑎 SRTT =1
2(𝑎𝑅1̅̅̅̅̅+𝑎𝑅2̅̅̅̅̅) 
Where:  
𝑎𝑅𝑛̅̅̅̅̅ is the arithmetic mean of the mfdd for the n -th test of the SRTT.  
In the case of the order of testing R1 – T1 – T2 – R2, the weighted averages 
waSRTT of the SRTT to be used in the comparison of the performance of the 
candidate tyre shall be taken to be:  
𝑤𝑎 SRTT =2
3𝑎𝑅1̅̅̅̅̅+1
3𝑎𝑅2̅̅̅̅̅  for comparison with the candidate tyre T1 and  
𝑤𝑎 SRTT =1
3𝑎𝑅1̅̅̅̅̅+2
3𝑎𝑅2̅̅̅̅̅  for comparison with the candidate tyre T2.  " 
Paragraph 3.4.1.3., amend to read:  
"3.4.1.3.  The snow grip index (SG) of a candidate tyre Tn shall be computed as the 
quotient of the arithmetic mean 𝑎Tn̅̅̅̅̅ of the mfdd of the tyre  Tn and the 
applicable weighted average wa SRTT of the SRTT:  
𝑆𝐺(Tn)=𝑎Tn̅̅̅̅̅
𝑤𝑎 SRTT 
 " 
Paragraph 3.4.2., amend to read:  
"3.4.2.  Statistical validations  
 The sets of repeats of measured or computed mfdd for each tyre should be 
examined for normality, drift, eve ntual outliers.  
 The consistency of the arithmetic means 𝑎̅ and corrected sample standard 
deviations 𝜎𝑎 of successive braking tests of SRTT should be examined.  
In addition and in order to take in account possible test evolution, the 
coefficient of valida tion CVal a(SRTT) is calculated on the basis of the average 
values of any two consecutive groups of the minimum 6 runs of the Standard 
Reference Test Tyre according to  E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
15 𝐶𝑉𝑎𝑙 𝑎(SRTT )=100 % × |𝑎𝑅2̅̅̅̅̅− 𝑎𝑅1̅̅̅̅̅
𝑎𝑅1̅̅̅̅̅| 
The coefficient of validation CVal a(SRTT) shall not differ by more than  5 per 
cent.  
 The coefficient of variation CV a , as defined in paragraph 3.1.1. of this annex, 
of any braking test shall be less than 6  per cent.  
 If those conditions are not met, tests  shall be performed again after re -
grooming the test course."  
Paragraph 4.1., amend to read:  
"4.1.  (omitted)"  
Paragraph 4.2., amend to read:  
"4.2. Methods for measuring snow grip index  
Snow performance is based on a test method by which the average acceleration 
in an acceleration test, of a candidate tyre is compared to that of a standard 
reference tyre.  
The relative performance shall be indicated by a snow grip index (SG).  
When tested in accordance with the acceleration test in paragraph 4.7. below,  
the average acceleration of a candidate snow tyre shall be at least 1.25 
compared to one of the two equivalent Standard Reference Test Tyres 
SRTT19.5 and SRTT22.5. " 
Paragraph 4.7., amend to read:  
"4.7. Acceleration on snow test procedure for snow grip ind ex of Class C3 " 
Paragraph 4.7.5.4., amend to read:  
"4.7.5.4.  For every candidate tyre and the standard reference tyre, the acceleration test  
runs shall be repeated a minimum of 6 times and the coefficients of variation  
CV AA shall be lower than or equal to 6 per cent. CV AA shall be calculated for 
minimum 6 valid runs according to  
𝐶𝑉𝐴𝐴=100% ∙𝜎𝐴𝐴
𝐴𝐴̅̅̅̅ 
where  
𝜎𝐴𝐴=√1
𝑁−1∑ (𝐴𝐴 𝑖−𝐴𝐴̅̅̅̅)2 𝑁
𝑖=1  denotes the corrected sample standard 
deviation and  
  𝐴𝐴̅̅̅̅ the arithmetic mean of the Average Accelerations ( 𝐴𝐴 𝑖) of N test runs. " 
Paragraph 4.8.1., amend to read:  
"4.8.1.  Calculation of the average acceleration AA  
Each time the measurement is repeated , the average acceleration AA (m ∙ s-2) 
is calculated by  
𝐴𝐴= 𝑆𝑓2−𝑆𝑖2
2𝐷 
Where D (m) is the distance covered between the initial speed Si (m ∙ s-1) and 
the final speed Sf (m ∙ s-1)."  E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
16 Paragraphs 4.8.2. and 4.8.3., amend to read:  
"4.8.2.  Validation of results  
For the candidate tyres:  
The coefficient of variation CV AA of the average acceleration is calculated 
according to the formula in 4.7.5.4. of this Annex for all the candidate tyres. If 
one coefficient of variation is greater than 6 per cent, discard the data for this 
candidate tyre and repeat the test.  
For the ref erence tyre:  
If the coefficient of variation CV AA of the average acceleration calculated 
according to the formula in 4.7.5.4. of this Annex for each group of min 6 runs 
of the reference tyre is higher than 6 per cent, discard all data and repeat the 
test f or all tyres (the candidate tyres and the reference tyre).  
In addition and in order to take in account possible test evolution, the 
coefficient of validation CVal AA(SRTT) is calculated on the basis of the 
average values of any two consecutive groups of min imum 6 runs of the 
reference tyre according to  
𝐶𝑉𝑎𝑙 𝐴𝐴(SRTT )=100 % × |𝐴𝐴 2̅̅̅̅̅− 𝐴𝐴 1̅̅̅̅̅
𝐴𝐴 1̅̅̅̅̅| 
If the coefficient of validation is greater than 6 per cent, discard the data for all 
the candidate tyres and repeat the test.  
4.8.3.  Calculation of the weighted ave rages  
Weighted averages waSRTT of the average accelerations of two successive tests 
of the SRTT are calculated according to Table 1:  
Table 1  
If the number of sets of candidate 
tyres between two successive runs 
of the reference tyre is:  and the set of candidate 
tyres to be qualified is:  then 𝑤𝑎SRTT is calculated by applying the 
following:  
1    R – T1 – R T1 𝑤𝑎 SRTT =1
2(𝐴𝐴 𝑅1̅̅̅̅̅̅̅+𝐴𝐴 𝑅2̅̅̅̅̅̅̅) 
 
2    R – T1 – T2 – R T1 
T2 𝑤𝑎 SRTT =2
3𝐴𝐴 𝑅1̅̅̅̅̅̅̅+1
3𝐴𝐴 𝑅2̅̅̅̅̅̅̅ 
𝑤𝑎 SRTT =1
3𝐴𝐴 𝑅1̅̅̅̅̅̅̅+2
3𝐴𝐴 𝑅2̅̅̅̅̅̅̅ 
 
3    R – T1 – T2 – T3 – R T1 
T2 
T3 𝑤𝑎 SRTT =3
4𝐴𝐴 𝑅1̅̅̅̅̅̅̅+1
4𝐴𝐴 𝑅2̅̅̅̅̅̅̅ 
𝑤𝑎 SRTT =1
2(𝐴𝐴 𝑅1̅̅̅̅̅̅̅+𝐴𝐴 𝑅2̅̅̅̅̅̅̅) 
𝑤𝑎 SRTT =1
4𝐴𝐴 𝑅1̅̅̅̅̅̅̅+3
4𝐴𝐴 𝑅2̅̅̅̅̅̅̅ 
 
 
where 𝐴𝐴 𝑅𝑛̅̅̅̅̅̅̅ is the arithmetic mean of the average accelerations in the n -th test 
of the Standard Reference Test Tyre."  
Paragraph 4.8.4., shall be  delete d.  
Paragraph 4.8.5., renumber as 4.8.4. and amend to read:  E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
17 "4.8.4.  Calculation of the relative snow grip index of the tyre  
The snow grip index represents the relative performance of the candidate tyre 
compared to the reference tyre.  
𝑆𝐺(Tn)=𝐴𝐴 Tn̅̅̅̅̅̅̅
𝑤𝑎 SRTT 
where 𝐴𝐴 𝑇𝑛̅̅̅̅̅̅̅ is the arithmetic mean of the average accelerations of the n -th 
candidate tyre " 
Paragraph 4.8.6., renumber as 4.8.5.  
Annex 7 - Appendix 2, amend to read:  
"… 
Part 1 - Report  
… 
2. Name and address of manufacturer:  ................................ ................................ .............   
… 
4. Brand name and trade description:  ................................ ................................ ...............   
… 
7. Snow grip index relative to SRTT according to paragraph 6.4.1.1.  
… 
Part 2 - Test data  
… 
4. Test tyre details and data:  
 SRTT (1st test)  Candidate 1 Candidate 2 SRTT (2nd test)  
Brand name      
Trade description/ 
commercial name      
Tyre size designation      
Service description      
Test rim width code      
Reference (test) inflation 
pressure(1) (kPa)      
Tyre loads F/R (kg)      
Tyre loads F/R (% of load 
associated to LI(2))     
Tyre pressure F/R (kPa)      
5. Test results: mean fully developed decelerations (m  ∙ s-2) / traction coefficient(3) 
Run number  Specification  SRTT (1st test)  Candidate 1  Candidate 2  SRTT (2nd test)  
1      
2      
3      E/ECE/324 /Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505 /Rev.2/Add.116/Rev.4/Amend. 3 
 
18 Run number  Specification  SRTT (1st test)  Candidate 1  Candidate 2  SRTT (2nd test)  
4      
5      
6      
      
      
      
Mean       
Standard 
deviation       
Coefficient of 
variation  CV a ≤ 6 %     
Coefficient of 
Validation  CVal a(SRTT) 
≤ 5 %     
SRTT weighted 
average       
Snow grip index   1.00    
" 
Annex 7 - Appendix 2, add new footnotes (1) and (2) and renumber the former footnote (1) 
to (3):  
"(1) for C2 tyres, corresponding to the indication of the inflation pressure marked on the sidewall as 
required by paragraph 4.1. of this Regulation  
(2) for C2 tyres, refer to single load 
(3) Strike out what does not apply. " 
Annex 7 - Appendix 3, amend to read:  
"… 
Part 1 - Report  
… 
2. Name and address of manufacturer:  ................................ ................................ ..................   
… 
4. Brand name and trade description:  ................................ ................................ ....................   
… 
Part 2 - Test data  
… 
4. Test tyre details and data:  
 SRTT (1st test)  Candidate 1  Candidate 2  Candidate 3  SRTT (2nd test)  
Brand name       
Trade description/ 
commercial name       
Tyre size designation       
Service description       E/ECE/324/ Rev.2/Add.116/Rev.4/Amend. 3 
E/ECE/TRANS/505/ Rev.2/Add.116/Rev.4/Amend. 3 
 
19 Test rim width code       
Reference (test) inflation 
pressure(1) (kPa)       
Tyre loads F/R (kg)       
Tyre loads F/R ( % of load 
associated to LI(2))      
Tyre pressure F/R (kPa)       
5. Test results: average accelerations (m  ∙ s-2) 
Run number  Specification  SRTT  
(1st test)  Candidate 1  Candidate 2  Candidate 3  SRTT (2nd test)  
1       
2       
3       
4       
5       
6       
       
       
       
Mean        
Standard  
deviation        
Slip ratio  
(per cent)        
Coefficient of 
variation  CV AA ≤ 6 %      
Coefficient of 
Validation  CVal AA(SRTT
) ≤ 6 %      
SRTT weig hted 
average        
Snow grip 
index   1.00     
…" 
Annex 7 - Appendix 3, add new footnotes (1) and (2):  
"(1) corresponding to the indication of the inflation pressure marked on the sidewall as required by 
paragraph 4.1. of this Regulation  
(2) refer to single load " 
      
 
GE.21 -01326(E)  
  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nations Regulations * 
(Revision 3, including the amendments which entered into force on 14 September 2017)  
_________  
  Addendum 116 – UN Regulation No. 117 
  Revision 4 - Amendment 4 
Supplement 12 to the 02 series of amendments  – Date of entry into force: 3 January  2021 
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. The authentic and legal binding text is:  
ECE/TRANS/WP.2 9/2020/75. 
_________  
UNITED NATIONS   
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, 
Equipment and Parts which can be Fitted and/or b e Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision 2).   E/ECE/324/Rev. 2/Add. 116/Rev.4/Amend. 4−E/ECE/TRANS/505/Rev. 2/Add. 116/Rev. 4/Amend. 4 
   
 
2 February  2021 
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 4 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 4 
2 Annex 3 
Paragraph 2.5.1., amend to read:  
"2.5.1.  General  
Four identical tyres shall be fitted on the test vehicle. In the case of C3 tyres 
with a load capacity index in excess of 121 and without any dual fitting 
indication, two of these tyres of the same type and range shall be fitted to the 
rear axle of the test vehicle; the front axle shall be fitted with tyres of size 
suitable for the axle load  and planed down to the minimum depth in order to 
minimize t he influence of tyre/road contact noise while maintaining a 
sufficient level of safety.  
In the case of C2 tyres with a load capacity index lower or equal to 121, with 
a section width wider than 200 mm, an aspect ratio lower than 55, a rim 
diameter code lo wer than 15 and without any dual fitting indication, two of 
these tyres of the same type and range shall be fitted to the rear axle of the test 
vehicle; the front axle shall be fitted with tyres of a size suitable for the axle 
load and planed down to the m inimum depth in order to minimize the influence 
of tyre/road contact noise while maintaining a sufficient level of safety.  
Tyres with special fitting requirements shall be tested in accordance with these 
requirements (e.g. rotation direction). The tyres s hall have full tread depth 
before being run -in. 
Tyres are to be tested on rims permitted by the tyre manufacturer. " 
     
 
GE.21 -18618(E)  
  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nat ions Regulations * 
(Revision 3, including the amendments which entered into force on 14 September 2017)  
_________  
  Addendum 116 – UN Regulation No. 117 
  Revision 4 - Amendment 5 
Supplement 13 to the 02 series of amendments  – Date of entry into force: 30 September  2021 
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool.  The authentic and legal binding text is:  
ECE/TRANS/WP.29/20 21/8 (as amended by paragraph 78 of the report 
ECE/TRANS/WP.29/1157) . 
_________  
UNITED NATIONS   
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, 
Equipment and Parts whic h can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision 2).   E/ECE/324/Rev. 2/Add. 116/Rev.4/Amend. 5−E/ECE/TRANS/505/Rev. 2/Add. 116/Rev. 4/Amend. 5 
   
 
10 December  2021 
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
2 Paragraph 2.18 ., amend to read:  
"2.18.  "Standard Reference Test Tyre " or " SRTT " means a tyre that is produced, 
controlled and stored in accordance with the standards of ASTM International:  
 (a) E1136 – 17 for the size P195/75R14 and referred to as "SRTT14",  
(b) F2872 – 16 for the size 225/75R16C and referred to as "SRTT16C",  
(c) F2871 – 16 for the size 245/70R19.5 and referred to as "SRTT19.5",  
 (d) F2870 – 16 for the size 315/70R22.5 and referred to as "SRTT22.5",  
(e) F2493 – 19 for the size  P225/60R16 and referred to as "SRTT16"."  
Paragraph 2.19.3 ., amend to read:  
"2.19.3.  "Control tyre " means a normal production tyre that is used to establish the wet 
grip or snow grip performance of tyre sizes unable to be fitted to the same 
vehicle as the standard reference test tyre — see paragraph  2.2.2.8. of Annex  5, 
part (B) and paragra ph 3.4.3. of Annex  7 to this Regulation."  
Paragraph 2.19.4 ., amend to read:  
"2.19.4.  "Wet grip index " (G) means the wet grip performance of a candidate tyre 
relative to that of the applicable standard reference test tyre."  
Paragraph 2.19.5.,  amend to read:  
"2.19.5.  "Snow grip index ("SG") " means the snow grip performance  of a candidate tyre 
relative to the performance of the applicable SRTT."  
Insert a new paragraph 4.3.1 . to read:  
"4.3.1.  In case the approval of a tyre  pursuant to this Regulation has been granted by 
the same Type Approval Authority than that granting the approval pursuant to 
UN Regulation No.  30 or UN Regulation No.  54, the approval mark pursuant 
to UN Regulation No. 30 or UN Regulation No.  54 can be co mbined with an 
indication of the applicable series of amendments to which the tyre was 
approved pursuant to UN Regulation No.  117 on the form of 2 digits (example 
"02" indicating that the UN Regulation No.117 approval was granted following 
the 02 series of  amendments) and the suffixes according to paragraph 5.2.2. 
using the addition sign "+", as described in Annex  2, Appendix  3 of this 
Regulation, for example "0236378 + 02S1WR2". " 
Paragraph 4.4., amend to read:  
"4.4.  The markings referred to in paragraph 4. 2. and the approval mark prescribed 
in paragraph 5.4. of this Regulation shall be clearly legible, indelible and raised 
above or sunk below the tyre surface."  
Paragraph 4.4.1., amend to read:  
"4.4.1.  The approval mark  shall be situated in the lower area of the tyre on at least one 
of its sidewalls. However, in the case of tyres identified by the "tyre to rim 
fitment configuration" symbol "A" or "U", the markings may be located 
anywhere on the outside sidewall of the tyre."   
Paragraph 5.4.4.,  amend to  read:  
"5.4.4.  The marking on the tyre sidewalls of suffix(es) to the approval number 
removes the requirement for any additional marking on the tyre of the specific 
type approval number for conformity to the Regulation(s) to which the suffix 
refers as per paragraph  5.2.2. above ." 
Paragraph 6.4.1.1., amend to read:  
"6.4.1.1.  Class C1, C2 and C3 tyres  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
3  The minimum snow grip index value, as calculated in the procedure described 
in Annex 7 and compared with the respective Standard Reference Test Tyre 
(SRTT ) shall be as follows:  
Class  
of tyre  Snow grip index  
(brake on snow method) (a) Snow grip index  
(spin traction method) 
(b) Snow grip index  
(acceleration method) (c) 
 Ref.s = SRTT14, 
SRTT16  Ref. =  
SRTT16C  Ref.s = SRTT14, 
SRTT16  Ref.s  = SRTT19.5, 
SRTT22.5  
C1  1.07 No 1.10 No 
C2 No 1.02 1.10 No 
C3 No No No 1.25 
  (a) See paragraph 3. of Annex 7 to this Regulation  
  (b) See paragraph 2. of Annex 7 to this Regulation  
  (c) See paragraph 4. of Annex 7 to this Regulation  " 
Paragraphs 7.1.3. and 7.1.4.,  renumber as 7.2. and 7.3.  
Insert new paragraphs 12.10. to 12.12. to read:  
"12.10.  Until 3 months after the date of entry into force of Supplement 13 to the 02 
series of amendments to this Regulation, Contracting Parties applying this 
Regulation can continue to grant type approvals according to the 02 series of 
amendments to this Regulation, without taking into account the provisions of 
Supplement 13.  
12.11.  Until 1 September 2024, Contracting Parties applying this Regulat ion may 
continue to grant type approvals according to the 02 series of amendments to 
this Regulation, based on snow performance test described in Annex 7 to this 
Regulation using SRTT14 as reference tyre.  (a) 
12.12.  Until 1 September 2024, Contracting Part ies applying this Regulation may 
continue to grant type approvals according to the 02 series of amendments to 
this Regulation, based on the test procedures for measuring wet grip described 
in Annex 5 of this Regulation, without taking into account the prov isions of 
Supplement 13."  
Add a new footnote (a) to read:  
  " (a) SRTT14 will be available  from the supplier until end of October 2021."  
Annex 1   
Item 8.4.,  amend to read:  
"8.4. Snow grip level of the representative tyre size,  see paragraph 2.7. of UN 
Regulation No. 117, as per item 7. of the test report in the appendix5 to 
Annex  7:………………. (Snow grip index) using the brake on snow method ,2 
spin traction method2 or acceleration method.2" 
Footnote 3,  renumber to 5.   E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
4 Item 16.1.,  amend to read:  
"16.1.  A list of documents in the approval file deposited at the Type Approval 
Authorities having delivered the approval and which can be obtained upon 
request.6" 
Footnote 4,  renumber to 6 and amend to read:  
"6  In the case of "snow tyre for use in severe snow conditions" a test report according to 
Appendix 2 or Appendix 3, as applicable,  to Annex  7 shall be submitted. " 
Annex 2  
Appendix 3, amend to read:  
"Combinations of markings of approvals issued in 
accordance with UN Regulations Nos. 117, 30 or 54  
Example 1  
… 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to UN Regulation No.  30 according to its  02 series of 
amendments (indicated by the first two digits of the approval number, "02") under approval 
number 0236378. It is also marked by "+ 02S1" which indicates that the tyre was also 
approved pursuant to UN Regulation No.  117 (02 series of amendment s) for rolling sound at 
stage 1.  
Example 2  
[…] 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to Regulation No.  30 according to its 02 series of amendments 
(indicated by the first two digits of the  approval number, "02") under approval number 
0236378. It is also marked by "+ 02S1WR2" which indicates that the tyre was also approved 
pursuant to Regulation No. 117 (02 series of amendments) for S1 (rolling sound at stage  1) 
W (wet adhesion) and R2 (roll ing resistance at stage 2)."  
Footnote 1 , delete.   
Annex 5  
Title, amend to read:  
"Test procedures for measuring the wet grip index of new 
tyres"  
Part (A),  
Paragraphs 1.1. and 1.2. , delete .  
Paragraph 1.3. , renumber  as 1.1.  
Insert new paragraphs 2.2 . and 2.3 . to read:  
"2.2.  "Braking test " means a series of a specified number of test runs of the same 
test tyre (set) repeated within a short time frame.  
2.3. "Test cycle " means a sequence of braking tests of the test tyres."  
Paragraph 2.2 ., renumber as 2. 4. and amend to read:  
"2.4.  "Test tyre " or "test tyre set " means a tyre or a tyre set whose wet grip braking 
performance is measured in a braking te st." 
  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
5 Paragraph 2.3 ., renumber as 2.5. and amend to read:  
"2.5.  "Candidate tyre " or "candidate tyre set " means a tyre or a tyre set whose wet 
grip braking performance is evaluated relative to that of a reference tyre or 
reference tyre set ." 
Paragraph 2.4 ., renumber as 2.6. and amend to read:  
"2.6.  "Reference tyre " or " Reference tyre set " means a tyre or a ty re set of Standard 
Reference Test Tyres SRTT16."  
Paragraph 2.5.  (former), delete .  
Paragraph 2.6 ., renumber as 2.7. and amend to read:  
"2.7.  "Braking force " means the longitudinal force, expressed in newtons, resulting  
from braking torque application."  
Paragraph 2.7 ., renumber as 2.8. and amend to read:  
"2.8.  "Average Braking Force Coefficient " (BFC) means, for the vehicle method, 
the ratio of the average deceleration in a braking test to the acceleration due to 
gravity  (rounded to 9.81  m∙s−2)." 
Insert a new paragraph 2.9. to read:  
"2.9.  "Dynamic braking force coefficient " (µ(t)) means, for the trailer (or tyre test 
vehicle) method, the ratio of the braking force to the vertical load acquired in 
real time."  
Paragraph 2.8 ., renumber as 2.10. and amend to read:  
"2.10.  "Peak braking force coefficient " (µpeak) means, for the trailer (or tyre test 
vehicle) method, the maximum value of the dynamic braking force coefficient 
that occurs prior to lockup of the wheel as the braking torque is progressively 
increased."  
Paragraph 2.9., renumber  as 2.11.  
Paragraph 2.10 ., renumber as 2.12. and amend to read:  
"2.12.  "Vertical load " means the normal force, expressed in newtons, exerted on the 
road resulting from the mass supported b y the tyre."  
Paragraph 2.11., renumber  as 2.13.  
Insert a  new paragraph 2.14. to read:  
"2.14.  "Tyre set " means, for the trailer (or tyre test vehicle) method, one (1) tyre and, 
for the vehicle method, four (4) tyres."  
Insert a new paragraph 2.15. to read:  
"2.15.  "Instrumented passenger car " means a commercialized passenger car 
equipped with an Antilock Braking System (ABS) and the measuring 
equipment listed in paragraph  4.1.2.2. of this Annex."  
Paragraph 3.1.1 ., amend t o read:  
"3.1.1.  The surface shall have a dense asphalt surface with a uniform gradient of not 
more than 2 per cent in both longitudinal and lateral directions and shall not 
deviate more than 6  mm when tested with a 3  m straight edge."  
Paragraph 3.1.4 ., ame nd to read:  
"3.1.4.  The average macro texture depth as measured in accordance with ASTM E965 -
96 (Reapproved 2006) by a sand patch shall be 0.7  ± 0.3) mm. In case the 
vehicle method is used, the average macro texture depth shall be determined 
in both lanes where the tyres are going to brake. " 
  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
6 Paragraph 3.1.5 ., amend to read:  
"3.1.5.  The wetted frictional properties of the surface shall be measured using the 
Standard Reference Test Tyre SRTT16 either with the method described in 
paragraph  3.2.1. of this Ann ex in case the vehicle method (according to 
paragraph  4.1. below) is used, or with the method described in  paragraph  3.2.2. 
in this Annex in case the trailer (or tyre test vehicle) method is used."  
Paragraph 3.2.1. , amend to read : 
"3.2.1.  Using the procedu re described in paragraph  4.1. of this Annex, perform two 
braking tests of the reference tyre, each consisting of at least six (6) valid test 
runs in the same direction on aligned segments of the track. The braking tests 
shall cover the entire potential br aking area, including where the texture depth 
was measured.  
Evaluate the braking tests as described in paragraphs  4.1.6.1. and 4.1.6.2. of 
this Annex. If the coefficient of variation of one braking test CV BFC exceeds 
4 per cent, dismiss the results and repeat the braking tests.  
For each braking test, the arithmetic mean 𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅ of the average Braking Force 
Coefficients shall be corrected for effects of temperature as follows:  
𝐵𝐹𝐶 ave,corr =𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
where  
ϑ is the wetted surface temperature in degrees Celsius,  
𝑎= 0.002  ℃ −1 and 𝜗0=20 ℃ . 
For each braking test, the temperature -corrected average Braking Force 
Coefficient ( BFC ave,corr ) shall be not less than 0.57 and not greater than 0.79.  
The arith metic means of the temperature -corrected average Braking Force 
Coefficients of the two braking tests shall not differ by more than 10  per cent 
of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 ave,corr )=2∙|𝐵𝐹𝐶 ave,corr,1 −𝐵𝐹𝐶 ave,corr,2
𝐵𝐹𝐶 ave,corr,1 +𝐵𝐹𝐶 ave,corr,2|≤10 % 
" 
Paragraph 3.2.2 ., amend to read:  
"3.2.2. Using the procedure described in paragraph  4.2. of this Annex, perform in the 
same area where the average macro texture depth was measured one braking 
test of the reference tyre, consisting of at least six (6) valid test runs in the same 
direction.  
 Evaluate the braking test as described in paragraphs  4.2.8.1. and 4.2.8.2. of this 
Annex. If the coefficient of variation CV µ exceeds 4 per cent, dismiss the 
results and repeat the braking test.  
 The arithmetic mean ( 𝜇peak̅̅̅̅̅̅) of the measured peak braking force  coefficients 
shall be corrected for effects of temperature as follows:  
𝜇peak,corr =𝜇peak̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
 where  
ϑ is the wetted road su rface temperature in degrees Celsius,  
𝑎= 0.002  ℃ −1  and  𝜗0=20 ℃ . 
The temperature -corrected average peak braking force coefficient  (µpeak,corr ) 
shall be not less than 0.65 and not greater than 0.90."  
  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
7 Paragraph 3.3 ., amend to read:  
"3.3.  Atmospheric conditions  
The wind conditions shall not interfere with wetting of the surface (wind -
shields are allowed).  
The wetted surface temperature and the ambient temperature shall be between:  
Category of use  Wetted surface 
temperature  Ambient tempera ture 
Normal tyres  12 °C – 35 °C  12 °C – 40 °C  
Snow tyres  5 °C – 35 °C  5 °C – 40 °C  
 Snow tyres for use in severe 
snow conditions  5 °C – 20 °C  5 °C – 20 °C  
Special use tyres  not applicable  not applicable  
Moreover, the wetted surface temperature shall not vary during the test by 
more than 10  °C. 
The ambient temperature shall remain close to the wetted surface temperature; 
the difference between the ambient and the wetted surface temperatures shall 
be less than 10  °C." 
Paragraph 4.1.1 ., amend to read:  
"4.1.1.  Principle  
The testing method covers a procedure for measuring the deceleration 
performance of C1 tyres during braking, using an instrumented passenger car.  
Starting with a defined initial speed, the brakes are applie d hard enough on 
four wheels at the same time to activate the ABS. The average deceleration is 
calculated between two pre -defined speeds."  
Paragraph 4.1.2.1 ., amend to read:  
"4.1.2.1.  Vehicle  
Any commercialized passenger car, preferably not older than 5 years, type 
approved pursuant to UN Regulation No. 13 -H with regards to its braking 
system, which is fitted with an anti -lock system (ABS), shall be considered as 
suitable for the purpose of the test provided that the mechanical conditions of 
the passenger  car meet the car manufacturer’s recommendations and no 
warning from ABS (e.g. warning lights) is displayed.  
Permitted modifications on the passenger car are as follows:  
(a) Those allowing the number of tyre sizes that can be mounted on the 
vehicle to be i ncreased;  
(b) Those permitting automatic activation of the braking device to be 
installed;  
(c) Those permitting the vehicle to be guided or accelerated externally.  
Any other modification of the vehicle and specifically of the  braking system is 
prohibited."  
Paragraph 4.1.2.2 ., amend to read:  
"4.1.2.2.  Measuring equipment  
The exposed portions of the system shall tolerate 100  per cent relative 
humidity (rain or spray) and all other conditions, such as dust, shock and 
vibrations, which may be encountered in regular operation.  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
8 The vehicle shall be fitted with a sensor suitable  for measuring speed on a wet 
surface and distance covered between two speeds.  
To measure vehicle speed, a fifth wheel or non -contact precision (including 
e. g. radar, GPS, etc.) speed -measuring system shall be used.  
The following tolerances shall be resp ected:  
(a) For speed measurement: ±  1 % or ±  0.5 km/h, whichever is greater;  
(b) For distance: ±  1 ∙ 10–1 m." 
Paragraph 4.1.3., amend to read:  
"4.1.3.  Conditioning of the test track and wetting condition  
 The test track surface shall be watered at least h alf an hour prior to testing in 
order to equalize the surface temperature and water temperature. External 
watering should be supplied continuously throughout testing. For the whole 
testing area, the water depth shall be (1.0 ± 0.5) mm, measured from the pe ak 
of the pavement.  
 The test track should then be conditioned by conducting at least ten test runs 
with tyres not involved in the test programme at 90 km/h."  
Paragraph 4.1.4.1 ., amend to read:  
"4.1.4.1.  Tyre preparation and stabilization, rims and fitment  on the vehicle  
The test tyres shall be trimmed to remove all protuberances on the tread surface 
caused by mould air vents or flashes at mould junctions.  
Fit the test tyres on rims specified by a recognized tyre and rim standards 
organization as listed in Appendix 4 to Annex 6 to this Regulation. Rim width 
code shall not differ by more than 0.5 from the measuring rim width code. 
Ensure proper bead seating b y the use of a suitable lubricant. Excessive use of 
lubricant should be avoided to prevent slipping of the tyre on the wheel rim.  
The tyres should be stabilized in performance prior to testing, which means 
that no evolution of the BFC value in test runs sh ould be detectable; in any 
case there will be an ex -post verification according to paragraph  4.1.6.2. of this 
Annex. In all cases, tyre designed tread depth and designed tread block or rib 
integrity shall not change significantly with break -in, which means  the pace 
and "severity" of the break -in needs to be carefully controlled to avoid such 
changes.  
Place the fitted test tyres in a location such that they all have the same ambient 
temperature prior to testing and shield them from the sun to avoid excessive  
heating by solar radiation.  
Maximum spacer (adapter) width allowed to mount tyres on the vehicle is 
60 mm."  
Paragraph 4.1.4.2 ., amend to read:  
"4.1.4.2.  Tyre load  
The static load on each axle tyre shall lie between 60 per cent and 90 per cent 
of the teste d tyre load capacity. Tyre loads on the same axle should not differ 
by more than 10 per cent.  
It is prohibited to exceed the maximum axle load of the vehicle."  
Paragraph 4.1.4.3 ., amend to read:  
"4.1.4.3.  Tyre inflation pressure  
On the front axle, the infl ation pressures p shall be calculated as follows:  
𝑝=𝑝ref∙(1.3∙𝑄
𝑄ref)1.25
 E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
9 where  
pref  is the reference inflation pressure (250  kPa for standard -load and 
290 kPa for extra -load versions, regardless of the reference pressure in 
the applicable standard);  
Q is the average tyre vertical load on the front axle;  
Qref is the reference vertical load associated with the load -capacity index.  
On the rear axle, the inflation pressure shall be 220  kPa (for both standard -load 
and extra -load versions). The tyre pressure should be checked just prior to 
testing at ambient temperature and adjusted if required."  
Paragraph 4.1.5.1.1., amend to read:  
"4.1.5.1.1.  The passenger car is driven in a straight line up to (85  ± 2) km/h."  
Paragraph 4.1.5.1.2 ., amend to rea d: 
"4.1.5.1.2.  Once the passenger car has reached (85 ± 2) km/h , the brakes shall always be 
activated at the same place on the test track referred to as "braking starting 
point", with a longitudinal tolerance of 5  m and a transverse tolerance of 0.5 m. 
Braking tests shall occur on the same lanes and in the same direction that was 
used to examine the surface, including where the macro texture depth was 
measured,  in accordance with paragraphs  3.1.4. and 3.1.5. above  (with a 
transverse tolerance of 0 .5 m)." 
Paragraph 4.1.5.1.3.2 ., amend to read:  
"4.1.5.1.3.2.  The manual activation of the brakes depends on the type of transmission as 
follows. In both cases, the pedal effort shall be high enough to activate the 
ABS.  
For manual transmission, as soon as t he driver is in the measuring zone and 
having reached (85  ± 2) km/h, the driver should release the clutch and depress 
the brake pedal sharply, holding it down as long as necessary to perform the 
measurement.  
For automatic transmission, as soon as the drive r is in the measuring zone and 
having reached (85  ± 2) km/h, the driver should select neutral gear and then 
depress the brake pedal sharply, holding it down as long as necessary to 
perform the measurement.  
For each braking test and for tyres not tested bef ore, the first two runs shall be 
discarded."  
Paragraph 4.1.5.1.4 ., amend to read:  
"4.1.5.1.4.  If any of the specifications listed above (including speed tolerance, 
longitudinal and transverse tolerance for the braking starting point, and braking 
time) are not met when a test run is made, the test run is invalidated  and a new 
test run is made."  
Paragraph 4.1.5.2 ., amend to read:  
"4.1.5.2.  Braking test and test cycle  
Within the same test cycle, each test run of each braking test shall be made in 
the same dire ction and in accordance with paragraph  4.1.5.1. of this Annex. 
Several test cycles may be performed consecutively, where the final braking 
test of the reference tyre set of a test cycle may serve as the initial braking test 
of the reference test tyre set f or the next test cycle.  
Up to three different candidate tyre sets may be measured within the same test 
cycle according to the following procedure:"  
Paragraph 4.1.5.2.1 ., amend to read:  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
10 "4.1.5.2.1.  Initial braking test of the reference tyre (R i): First, the reference tyre set is 
mounted on the instrumented passenger car and at least four (4) valid test runs 
shall be made."  
Paragraph 4.1.5.2.2 ., amend to read:  
"4.1.5.2.2.  Braking test of a candidate tyre set (T n): The reference tyre set is replaced by 
a candidate tyre set (T n) and at least six (6) valid test runs of the candidate tyres 
shall be performed."  
Paragraph 4.1.5.2.3 ., amend to read:  
"4.1.5.2.3.  After the braking test of the first candidate tyre set, up to two more candidate 
tyre sets may be measured."  
Paragraph 4.1.5.2.4 ., amend to read:  
"4.1.5.2.4.  Final braking test of the reference tyres ( Rf): The test cycle is closed by at least 
four (4) valid test runs of the same reference tyre set as at the beginning of the 
test cycle.  
Examples:  
(a) The run order for a test cycle of three candidate tyre sets (T 1 to T 3) 
would be the following:  
Ri – T1 – T2 – T3 – Rf 
(b) The run order for a braking test (consisting of two test cycles) of five  
candidate tyre sets (T 1 to T 5) would be the following:  
Ri – T1 – T2 – T3 – Rf/Ri – T4 – T5 – Rf" 
Paragraph 4.1.6.1. , amend to read:  
"4.1.6.1.  Calculation of the average Braking Force Coefficient  
For each valid test run j, the average Braking Force Coefficient BFC ave,j is 
calculated from the distance dj covered between 80  km/h and 20  km/h as 
follows:  
𝐵𝐹𝐶 𝑎𝑣𝑒 ,𝑗=𝑣𝑖2−𝑣𝑓2
2∙𝑑𝑗∙𝑔 
where  
vf is the final speed  in m/s; vf = 20 km/h = 5.556 m/s 
vi is the initial speed in m/s; vi = 80 km/h = 22.222 m/s  
dj is the distance covered  in test run j between vi and vf in meters;  
g is the acceleration due to gravity = 9.81 m∙s−2." 
Paragraph 4.1.6.2. , amend to read:  
"4.1.6.2.  Validation  of results  
The coefficient of variation  CV BFC is calculated as follows:  
𝐶𝑉𝐵𝐹𝐶 =100% ∙𝜎𝐵𝐹𝐶
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅ 
where  
𝜎𝐵𝐹𝐶 =√1
𝑁−1∑ (𝐵𝐹𝐶 𝑎𝑣𝑒 ,𝑗−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample 
standard deviation and  
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅ the arithmetic mean of the average Braking Force Coefficients BFC ave,j 
of N test runs.  
For the reference tyre:  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
11 (a) The coefficient of variation CV BFC of the initial and the final braking 
test of the reference tyre within one test cycle shall be less than or equal 
to 4 per cent.  
(b) The arithmetic means of the average Braking Force Coefficients of the 
initial and the final braking test shall not differ by more than 5  per cent 
of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 𝑎𝑣𝑒)=100% ∙ 2∙|𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)|≤5% 
where  
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri) / 𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf) is the arithmetic mean of the average Braking 
Force Coefficients in the initial/final braking test of the reference tyre 
within a test cycle.  
(c) The temperature -corrected average Braking Force Coefficients 
(BFC ave,corr , see paragraph  3.2.1. of this Annex) as calculated from the 
initial and from the final braking tests of the reference tyre within a test 
cycle shall be not less than 0.57 and not greater than 0.79.  
If one or more of the above conditions is not met, the complete test cycle shall 
be performed again.  
For the candidate tyres (T):  
The coefficient of variation CV BFC is calculated for each candidate tyre set. If 
one coefficient of variation is higher than 4  per cent, the data shall be discarded 
and the braking test repeated for that candidate tyre set."  
Paragraph 4.1.6.3. , amend to read:  
"4.1.6.3.  Calculation of adjusted average Braking Force Coefficient  
 The average Braking Force Coefficient of the reference tyre set used for the 
calculation of its braking force coefficient is adjusted according to the 
positioning of each candidate tyre set in a gi ven test cycle.  
 This adjusted average Braking Force Coefficient of the reference tyre  
𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅) is calculated in accordance with Table 1 where 𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(𝑅𝑖) is the 
arithmetic mean of the average Braking Force Coefficients in the initial 
braking test of the reference tyre set (R i) and 𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(𝑅𝑓) is the arithmetic 
mean of the average Braking Force Coefficients in the final braking test of the 
same reference tyre set (R f) within the test cycle.  
Table 1  
If the number and the sequence 
of candida te tyre sets within one 
test cycle is:  and the candidate tyre 
set to be qualified 
within this test cycle is:  the corresponding adjusted average Braking Force Coefficient of 
the reference tyre is calculated as follows:  
1 Ri – T1 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=12⁄∙[𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓)] 
2 Ri – T1 – T2 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=23⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+13⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
T2 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=13⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+23⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
3 Ri – T1 – T2 – T3 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=34⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+14⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
T2 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=12⁄∙[𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓)] 
T3 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=14⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+34⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
" 
Paragraph 4.1.6.4. , delete . 
Paragraph 4.1.6.5. , renumber as 4.1.6.4. and amend to read:  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
12 "4.1.6.4.  Calculation  of the wet grip index of the candidate tyre  
 The wet grip index G(T n) of the candidate tyre T n (n = 1, 2 or 3) is calculated 
as follows:  
𝐺(T𝑛)=𝐾vehicle ∙{𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛)−[𝑎∙∆𝐵𝐹𝐶 (R)+𝑏∙∆𝜗+𝑐∙(∆𝜗)2+𝑑∙∆𝑀𝑇𝐷 ]} 
where : 
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛) is the arithmetic mean of the average Braking Force Coefficients 
of the candidate tyre T n within a braking test;  
∆𝐵𝐹𝐶 (𝑅)=𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)−𝐵𝐹𝐶 (𝑅0) 
BFC adj(R) is the adjusted average Braking Force Coefficient in accordance 
with Table  1; 
BFC (R0) = 0.68 is fixed as the Braking Force Coefficient for the reference tyre 
in the reference conditions;  
∆𝜗=𝜗−𝜗0 
ϑ is the measured wet surface temperature in degrees Celsius when 
the candidate tyre T n is tested;  
ϑ0 is the wetted surface reference temperat ure for the candidate tyre 
according to its category of use as listed in Table  2; 
∆𝑀𝑇𝐷 =𝑀𝑇𝐷 −𝑀𝑇𝐷 0 
MTD  is the measured macro texture depth in mm of the track (see 
paragraph  3.1.4. of this Annex);  
MTD 0 = 0.8  mm is the macro texture depth of the reference track;  
Kvehicle  = 1.87  is a factor to grant consistency between previous calculation of 
the wet grip index and this one, and to ensure convergence 
between vehicle and trailer method and  
coefficients a, b, c and d are given in Table  2. 
Table  2 
Category of use  ϑ0 
(°C) a 
 b 
(°C−1) c 
(°C−2) d 
(mm−1) 
Normal tyre  20 +0.99382  +0.00269  −0.00028  −0.02472  
Snow tyre  15 +0.92654  −0.00121  −0.00007  −0.04279  
 Snow tyre for use in 
severe snow conditions  10 +0.72029  −0.00539  +0.00022  −0.03037  
Special -use tyre  not defined  
" 
Paragraph 4.1.7. , amend to read:  
"4.1.7.  When a direct comparison between a candidate tyre and a reference tyre on the 
same vehicle is not possible the test method using a trailer or a tyre test vehicle 
(paragraph  4.2. of this Annex) shall be used."  
Paragraphs 4.1.7.1. to 4.1.7.3. , delete .  
Paragraph 4.1.7.4 . renumber as 3.4. and amend to read:  
"3.4.  Replacement of reference tyres  
 When  irregular wear or damage results from tests, or when wear or aging 
influences the test results, the use of the reference tyre shall be discontinued."  
Paragraph 4.2.2.1. , amend to read:  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
13 "4.2.2.1.  Tow vehicle and trailer or tyre test vehicle  
 The tow vehicle or the tyre test vehicle shall have the capability of maintaining 
the specified speed of (65  ± 2) km/h even under the maximum braking forces.  
 The trailer  or the tyre test vehicle shall be equipped with one place where the 
tyre can be fitted for me asurement purposes, hereinafter called "test position", 
and the following accessories:  
(a) Equipment  to activate brakes in the test position;  
(b) A water tank to store sufficient water to supply the road surface wetting 
system, unless external watering is used;  
(c) Recording equipment to record signals from transducers installed at the 
test position and to monitor water application rate if the self -watering 
option is used.  
In the case of the one axle trailer, in order to reduce "pitch disturbance", the 
longitudinal distance from the centre line of the articulation point of  the 
coupling to the transverse centre line of the axle of the trailer shall be at least 
ten times the "hitch height" or the "coupling (hitch) height".  
In order to reduce "lateral disturban ce", the trailer or the tyre test vehicle should 
be technically designed to minimize lateral displacement during the application 
of maximum braking force. Visual lateral displacement should be avoided 
during braking manoeuvre.  
The maximum variation of toe -settings and camber angle for the test position 
shall be within ±0.5° with maximum vertical load. Suspension arms and 
bushings shall have sufficient rigidity necessary to minimize free play and 
ensure compliance under application of maximum braking forces.  The 
suspension system shall provide adequate load -carrying capacity and be of 
such a design as to isolate suspension resonance.  
The test position shall be equipped with a typical or special automotive brake 
system which can apply sufficient braking torque  to produce the maximum 
value of braking test wheel longitudinal force at the conditions specified.  
The brake application system shall be able to control the time interval between 
initial brake application and peak longitudinal force as specified in paragr aph 
4.2.7.1. below.  
The trailer or the tyre test vehicle shall be designed to accommodate the range 
of candidate tyre sizes to be tested.  
The trailer or the tyre test vehicle shall have provisions for adjustment of 
vertical load as specified in paragraph 4 .2.5.2. below."  
Paragraph 4.2.2.2. , amend to read:  
"4.2.2.2.  Measuring equipment  
… 
(a) The minimum frequency response shall be flat from 0 Hz to 100  Hz 
within ±1  per cent full scale;  
…" 
Paragraph 4.2.3. , amend to read:  
"4.2.3.  Conditioning of the test track  
 The test track should be conditioned by conducting at least ten test runs with 
tyres not  involved in the test program at (65  ± 2) km/h."  
  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
14 Paragraph 4.2.4. , amend to read:  
"4.2.4.  Wetting  conditions  
The surface may be wetted from the track -side ("external watering") or by a 
wetting system incorporated in the test vehicle or the trailer ("self -watering").  
4.2.4.1.  If "external watering" is used, the test track surface shall be watered at least 
half an hour prior to testing in order to  equalize the surface temperature and 
water temperature. External watering should be supplied continuously 
throughout testing. For the braking lanes used, the water depth shall be 
between 0.5  mm and 1.5  mm, measured from the peak of the pavement.  
4.2.4.2.  For "self -watering" systems, the tow  vehicle and trailer or the tyre test vehicle 
is equipped with a pavement -wetting system, less the storage tank, which, in 
the case of the trailer, is mounted on the tow vehicle. The water being applied 
to the pavement a head of the test tyres shall be supplied by a nozzle suitably 
designed to ensure that the water layer encountered by the test tyre has a 
uniform cross section at the test speed with a minimum splash and overspray.  
 The nozzle configuration and position sha ll ensure that the water jets are 
directed towards the test tyre and pointed towards the pavement at an angle of 
20° to 30°.  
 The water shall strike the pavement 250 mm to 450 mm ahead of the centre of 
tyre contact. The nozzle shall be located 25 mm above the pavement or at the 
minimum height required to clear obstacles which the tester is expected to 
encounter, but in no case more than 100 mm above the pavement.  
 The water layer shall be at least 25 mm wider than the test tyre tread and 
applied so the tyre  is centrally located between the edges. Water delivery rate 
shall ensure a water depth of (1.0  ± 0.5) mm and shall be consistent throughout 
the test to within ±10  per cent. The volume of water per unit of wetted width 
shall be directly proportional to the  test speed. The quantity of water applied 
at 65 km/h shall be 18  l/s per meter of width of wetted surface in case of a 
water depth of 1.0 mm."  
Paragraph 4.2.5.1. , amend to read:  
"4.2.5.1.  Tyre preparation and stabilization and rims  
 The test tyres shall be trimmed to remove all protuberances on the tread surface 
caused by mould air vents or flashes at mould junctions.  
 The test tyre shall be mounted on a rim specified by a recognized tyre and rim 
standards organization as listed in Appendix 4 to Ann ex 6 to this Regulation. 
The rim width code shall not differ by more than 0.5 from the measuring rim 
width code.  
 A proper bead seat should be achieved by the use of a suitable lubricant. 
Excessive use of lubricant should be avoided to prevent slipping of  the tyre on 
the wheel rim.  
 The tyres should be stabilized in performance prior to testing, which means 
that no evolution of the μpeak value in test runs should be detectable; in any case 
there will be an ex -post verification according to paragraph 4.2.8. 2. of this 
Annex. In all cases, tyre designed tread depth and designed tread block or rib 
integrity shall not change significantly with break -in, which means the pace 
and "severity" of the break -in needs to be carefully controlled to avoid such 
changes.  
The test tyres/rim assemblies shall be stored in a location for a minimum of 
two hours such that they all have the same ambient temperature prior to testing. 
They should be shielded from the sun  to avoid excessive heating by solar 
radiation."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
15 Paragraph 4.2.5 .2., amend to read:  
"4.2.5.2.  Tyre load  
 The test load on the test tyre is (75  ± 5) per cent of the tyre load capacity."  
Paragraph 4.2.6.1. , amend to read:  
"4.2.6.1.  The test tyre set shall be installed on the measuring device and loaded to the 
specified test load according to paragraph 4.2.5.2. of this Annex.  
 For one -axle trailers , the hitch height and transverse position shall be adjusted  
in order to avoid any disturbance of the measuring results."  
Paragraph 4.2.7.1.1. , amend to read:  
"4.2.7.1 .1. The tow vehicle or the tyre test vehicle is driven onto the test track in a straight 
line at the specified test speed (65  ± 2) km/h."  
Paragraph 4.2.7.1.3. , amend to read:  
"4.2.7.1.3.  For self -watering system, water shall be delivered to the pavement ahead of the 
test tyre approximately 0.5 s prior to brake application."  
Paragraph 4.2.7.1.4. , amend to read:  
"4.2.7.1.4.  The brakes shall be activated within an area of six (6) meters in the longitudinal 
direction and 0.5 meters in the transversal  direction of a measurement point of 
the wetted frictional properties of the surface and sand depth in accordance 
with paragraphs  3.1.4. and 3.1.5. above. The test shall be run in the same 
direction as in paragraph  3.2.2. of this Annex. The rate of braking  application 
shall be such that the time interval between initial application of force and peak 
longitudinal force is in the range 0.2 s to 0.5 s."  
Paragraph 4.2.7.2. , amend to read:  
"4.2.7.2.  Test cycle  
 Within the same test cycle, each test run of each braking test shall be made in 
the same direction and in accordance with paragraph  4.2.7.1. of this Annex. 
Several test cycles may be performed consecutively, where the final braking 
test of the reference tyre set of a test cycle may serve as the initi al braking test 
of the reference tyre set for the next test cycle.  
  Up to three candidate tyre sets may be measured within the same test cycle, 
provided that the tests are completed within one day."  
Paragraph 4.2.7.2.1. , amend to read:  
"4.2.7.2.1.  Initial  braking test of the reference tyre set (R i): first, the reference tyre set is 
mounted and at least six (6) valid test runs shall be made in accordance with 
paragraph  4.2.7.1. above."  
Paragraph 4.2.7.2.2. , amend to read:  
"4.2.7.2.2.  Braking test of a candi date tyre set (T n): the reference tyre set is replaced by  a 
candidate tyre set and at least six (6) valid test runs with the candidate tyre set 
shall be performed."  
Paragraph 4.2.7.2.3. , amend to read:  
"4.2.7.2.3.  After the braking test of the first candid ate tyre set, up to two more candidate  
tyre sets may be measured."  
Paragraph 4.2.7.2.4. , amend to read:  
"4.2.7 .2.4. Final braking test of the reference tyre set (R f): the test cycle shall be closed by 
at least six (6) more valid test runs of the same reference tyre set as at the 
beginning of the test cycle.  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
16 Examples:  
(a) The run order for a test cycle with three candidate tyre sets (T 1 to T 3) 
would be the following:  
 Ri – T1 – T2 – T3 – Rf 
(b) The run order for a braking test (consisting of two test cycles) of five 
candidate tyre sets (T 1 to T 5) would be the following:  
 Ri – T1 – T2 – T3 – Rf/Ri – T4 – T5 – Rf " 
Paragraph 4.2.8.1. , amend to read:  
"4.2.8.1.  Calculation of the peak braking force coefficient  
For each test run, the peak braking force coefficient ( µpeak) is the highest value 
of µ(t) before lockup occurs calculated as follows for each test run. Analogue 
signals should be filtered to remove noise. Digitally recorded signals must be 
filtered using a moving average technique.  
𝜇(𝑡)=|𝑓ℎ(𝑡)
𝑓𝑣(𝑡)| 
where:  
 µ(t)  is the dynamic tyre braking force coefficient in real time;  
 fh(t) is the dynamic braking force in real time, in N;  
 fv(t) is the dynamic vertical load in real time, in N."  
Paragraph 4.2.8.2. , amend to read:  
"4.2.8.2.  Validation of results  
 The µpeak coefficient of variation CV µ is calculated as follows:  
𝐶𝑉𝜇=100% ∙𝜎𝜇
𝜇peak̅̅̅̅̅̅ 
where  
𝜎µ=√1
𝑁−1∑ (𝜇peak ,𝑗−𝜇peak̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample standard 
deviation and  
𝜇peak̅̅̅̅̅̅ the arithmetic mean of the peak braking force coefficients ( 𝜇peak ,𝑗) of N 
test runs.  
 For the reference tyre (R):   
(a) The coefficients of variation CVμ of the initial and the final braking tests 
of the reference tyre within one test cycle shall be less than or equal to 
4 per cent;  
(b) The arithmetic mean of the peak braking force coefficients of initial and 
the final braking test of the reference tyre wi thin one test cycle shall not 
differ by more than 5  per cent of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝜇𝑝𝑒𝑎𝑘 )=100% ∙2∙|𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)−𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)|≤5 % 
where  
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri) / 𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri) is the arithmetic mean of the peak braking 
force coefficients in the initial/final braking test of the reference tyre  
within a test cycle;  
(c) The temperature -corrected average peak braking force coefficients 
(µpeak,corr , see paragraph 3.2.2. of this Annex) as calculated from the E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
17 initial and from the final braking test of the reference tyre within a test 
cycle shall be not less than 0.65 and not greater than 0.90.  
If one or more of the above conditions is not met, the complete test cycle shall 
be performed again.  
 For the candidate tyre (s) (T n): 
  The coefficient of variation of the peak braking force coefficient CV µ is 
calculated for each candidate tyre. If one coefficient of variation is greater than 
5 per cent, the data shall be discarded and the braking test repeated for this 
candidate tyre."  
Paragraph 4.2.8.3. , amend to read:  
"4.2.8.3.  Calculation of the adjusted  average peak braking force coefficient of the 
reference tyre  
 The average peak braking force coefficient of the reference tyre used for the 
calculation of its braking force coefficient is adjusted according to the 
positioning of each candidate tyre in a g iven test cycle.  
 This adjusted average peak braking force coefficient of the reference tyre  
𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R) is calculated in accordance with Table 3 where 𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri) is the 
arithmetic mean of the peak braking force coefficients in the initial test of the 
reference tyre (R i) and 𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) is the arithmetic mean of the peak  braking 
force coefficients in the final test of the same reference tyre (R f) within one 
test cycle.  
Table 3  
If the number and the sequence of 
candidate tyre sets within one test 
cycle is:  and the candidate tyre 
set to be qualified within 
this test cycle is:  the corresponding adjusted peak braking force coefficients of the 
reference tyre is calculated as follows:  
1 Ri – T1 – Rf T1 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)=12⁄∙[𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)] 
2 Ri – T1 – T2 – Rf T1 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)=23⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+13⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) 
T2 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)=13⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+23⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) 
3 Ri – T1 – T2 – T3 – Rf T1 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)=34⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+14⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) 
T2 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(𝑅)=12⁄∙[𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)] 
T3 𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)=14⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+34⁄∙𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) 
" 
Paragraph 4.2.8.4. , delete . 
Paragraph 4.2.8.5. , renumber as 4.2.8.4. and amend to read:  
"4.2.8.4.  Calculation of the wet grip index of the candidate tyre  
 The wet grip index G(Tn) of the candidate tyre T n (n = 1, 2, 3) is calculated as 
follows:  
𝐺(T𝑛)=𝐾trailer ∙{𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(T𝑛)−[𝑎∙∆𝜇𝑝𝑒𝑎𝑘 (R)+𝑏∙∆𝜗+𝑐∙(∆𝜗)2+𝑑∙∆𝑀𝑇𝐷 ]} 
 where:  
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(T𝑛) is the arithmetic mean of the peak braking force coefficients of 
the candidate tyre T n within a braking test;  
∆𝜇𝑝𝑒𝑎𝑘 (R)=𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)−𝜇𝑝𝑒𝑎𝑘 (𝑅0) 
µpeak,adj (R) is the adjusted peak braking force coefficient in accordance with 
Table  3; E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
18 µpeak(R0) = 0.85 is fixed as the peak braking force coefficient for the reference 
tyre in the reference conditions;  
∆𝜗=𝜗−𝜗0 
ϑ  is the measured wet surface temperature in degrees Celsius when 
the candidate tyre T n is tested;  
ϑ0  is the wetted surface reference tempe rature for the candidate tyre 
according to its sidewall marking as listed in Table 4;  
∆𝑀𝑇𝐷 =𝑀𝑇𝐷 −𝑀𝑇𝐷 0 
MTD  is the measured macro texture depth of the track  
MTD 0 = 0.8  mm is fixed as the macro texture depth of the reference track;  
Ktrailer = 1.50  is a factor to grant consistency between previous calculation of 
the wet grip index and this one, and to ensure convergence 
between vehicle and trailer method and  
coefficient a, b, c and d are given in Table 4.  
Table 4  
Category of use  ϑ0 
(°C) a 
 b 
(°C−1) c 
(°C−2) d 
(mm−1) 
Normal tyre  20 +0.99757  +0.00251  −0.00028  +0.07759  
Snow tyre  15 +0.87084  −0.00025  +0.00004  −0.01635  
 Snow tyre for use in 
severe snow conditions  10 +0.67929  +0.00115  −0.00005  +0.03963  
Special -use tyre  not defined  
" 
Part (B),  
Paragraph 1.1.,  amend to read:  
"1.1.  Track characteristics  
The surface shall be a dense asphalt surface with a uniform gradient of not 
more than two per cent and shall not deviate more than 6 mm when tested with 
a 3 m straight edge.  
The test surface shall have a pavement of uniform age, composition, and wear. 
The test surface shall be free of loose material or foreign deposits.  
The maximum chipping size shall be from 8 mm to 13 mm.  
The average macro texture depth measured as specified in ASTM E 965 -96 
(reap proved 2006) shall be (0.7 ± 0.3) mm.   
The surface friction value for the wetted track shall be established by one or 
other of the following methods according to the discretion of the Contracting 
Party."  
Paragraph 1. 1.1., amend to read:  
"1.1.1.   Standard Reference Test Tyre (SRTT) method  
This method uses the Standard Reference Test Tyre SRTT16.  
Using the procedure described in paragraph  4.2. of part (A) of this Annex, 
perform in the same area where the average macro texture depth was measured 
one braking test of the reference tyre, consisting of at least six (6) valid test 
runs in the same direction.  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
19 Evaluate the braking test as described in paragraphs  4.2.8.1. and 4.2.8.2. of 
part (A) of this Annex. If the coefficient of variation CV µ exceeds 4  per cent, 
dismiss the results and repeat the braking test.  
The arithmetic mean ( 𝜇peak̅̅̅̅̅̅) of the measured peak braking force coefficients 
shall be corrected for the effects of temperature as follows:  
𝜇peak,corr =𝜇peak̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
where  
ϑ is the wetted track sur face temperature in degrees Celsius,  
𝑎= 0.002  ℃−1 and 𝜗0=20 ℃. 
The temperature corrected average peak braking force coefficient  (µpeak,corr ) 
shall be not less than 0.65 and not greater than 0.90.  
The test shall be conducted using the lanes and length of the track to be used 
for the wet grip test.  
For the trailer method, testing is run in such a way that braking occurs within 
10 meters distance of where the surface was characterized."  
Paragraph 1.1.2. , delete.   
Paragraph 1.1.3., renumber as 1.1.2 . 
Annex 5 – Appendix, amend to read : 
"Annex 5 – Appendix  
Test reports examples of wet grip index  
Example 1:  Test report of wet grip index using trailer or tyre test vehicle method  
Test report number:    Test date:   
      
Track:     Minimum:  Maximum:  
Texture depth (mm):    Wetted surface temp. (°C):    
µpeak,corr :   Ambient temp (°C):    
Water depth (mm):       
      
Speed (km/h):       
 
No. 1 2 3 4 5 
Brand       
Pattern/Trade 
description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) 
inflation pressure(1) 
(kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       
Rim      E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
20 Load (kg)       
Pressure (kPa)       
µpeak 1      
2      
3      
4      
5      
6      
7      
8      
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅       
Standard deviation, σµ      
CV µ ≤ 4 %       
CVal (µpeak) ≤ 5 %       
µpeak,corr (R)      
µpeak,adj (R)      
Wet grip index       
Wetted surface temp. 
(°C)      
Ambient temp. (°C)       
Remarks       
(1) for C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall as 
required by paragraph 4.1. of this Regulation  
Example 2:  Test report of wet grip index using vehicle method  
Test report number:    Test date:    Driver:   
         
Track:     Minimum:  Maximum:   Vehicle   
Texture depth (mm):    Wetted surface temp. (°C):     Brand:   
BFC ave,corr,1 :   Ambient temp (°C):     Model:   
BFC ave,corr,2 :       Type:   
CVal (BFC ave,corr ):       Year of registration:   
Water depth (mm):        Maximum axle load:  Front  Rear  
         
Initial speed (km/h):    Final speed (km/h):      
 
No. 1 2 3 4 5 
Brand       
Pattern/Trade 
description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) 
inflation pressure(1) 
(kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
21 Rim      
Front axle pressure 
(kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle pressure 
(kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Front axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
 Braking 
distance  
(m) BFC i Braking 
distance 
(m) BFC i Braking  
distance 
(m) BFC i Braking 
distance 
(m) BFC i Braking 
distance 
(m) BFC i 
Measurement  1           
 2           
 3           
 4           
 5           
 6           
 7           
 8           
 9           
 10           
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅       
Standard deviation, 
σBFC      
CV BFC ≤ 4 %       
CVal (BFC ave) ≤ 5 %       
BFC ave,corr (R)      
BFC adj(R)      
Wet grip index       
Wetted surface temp. 
(°C)      
Ambient temp. (°C)       
Remarks       
(1) for C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation."  
Annex 7  
Paragraph 1.3. , amend to read:  
"1.3. "Traction test " means a series of a specified number of spin -traction test runs 
according to ASTM s tandard:  
(a) F1805 -06 in case SRTT14 is used as reference tyre or  
(b) F1805 -20 in case SRTT16 is used as reference tyre  
of the same tyre repeated within a short time frame. " 
Paragraph 2. , amend to read:  
"2. Spin traction method for Class C1 and C2 tyres (traction force test per 
paragraph 6.4. (b) of this Regulation)  
 The test procedure of ASTM standard F1805 -06 or F1805 -20, as applicable 
according to paragraph 1.3., shall be used to assess snow performance t hrough 
the traction performance index (TPI) on medium pack snow (The snow E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
22 compaction index measured with a CTI penetrometer1 shall be between 70  and 
80)."  
Paragraph 2.1. , amend to read:  
"2.1.  The test course surface shall be composed of a medium pack snow surface, as 
characterized in table A2.1 of ASTM standard F1805 -06 or ASTM F1805 -20, 
as applicable."  
Paragraph 2.2. , amend to read:  
"2.2.  The tyre load for testing shall be as per option 2 in paragraph 11.9.2. of ASTM 
standard F1805 -06 or ASTM F1805 -20, as applicable. When the SRTT16 is 
used as reference tyre, it shall be tested with a load of 531 kg at an inflation 
pressure of 240 kPa (cold)."  
Insert a new paragraph 2.3.  to read:  
"2.3.  The snow grip index (SG) of a candidate tyre Tn shall be computed as follows:  
𝑆𝐺(𝑇𝑛)=𝑓∙𝑇𝑃𝐼
100 
where  
(a) 𝑓=1.000  when using SRTT14 as reference tyre per 
ASTM F1805 -06, and  
(b) 𝑓=0.987  when using SRTT16 as reference tyre per 
ASTM F1805 -20, 
and 
TPI denotes the traction performance index as defined in ASTM F1805 -06 
or ASTM F1805 -20, as applicable."  
Insert a new paragraph 3.1.6.  to read:  
"3.1.6.  In order to run this test, the Standard Reference Test Tyres (SRTT) as shown 
in the following table shall be used:  
Class C1 tyres  Class C2 tyres  
SRTT14 or SRTT16  SRTT16C  
" 
Paragraph 3.4.1.3., amend to read:  
"3.4.1.3.  The snow grip index (SG) of a candidate tyre Tn shall be computed from the 
arithmetic mean 𝑎Tn̅̅̅̅̅ of the mfdd  of the tyre Tn and the applicable weighted 
average waSRTT of the SRTT as shown in the table:  
𝑆𝐺(Tn)=𝑓∙𝑎Tn̅̅̅̅̅
𝑤𝑎 SRTT 
where f is given in the following table  
Tyre class  Reference tyre  Factor  
C1 SRTT14  𝑓=1.000 
SRTT16  𝑓=0.980 
C2 SRTT16C  𝑓=1.000 
" 
Paragraph 3.4.3.1.,  amend to read:  
"3.4.3.1  The snow grip index of the control tyre C relative to the SRTT (SG1) is given 
by E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 5 
 
23 𝑆𝐺1=𝑆𝐺(C)=𝑓∙𝑎C̅̅̅
𝑤𝑎 SRTT 
where f is given in paragraph 3.4.1.3., and snow grip index of the candidate 
tyre Tn relative to the control tyre (SG2) is given by  
𝑆𝐺2=𝑎Tn̅̅̅̅̅̅
𝑤𝑎 C  
where 𝑤𝑎 C is the applicable weighted average of the control tyre, shall be 
established using the procedure in pa ragraphs 3.1. to 3.4.2. above.  
The snow grip index of the candidate tyre relative to the SRTT SG(Tn) shall 
be the product of the two resulting snow grip indices that is given by  
𝑆𝐺(𝑇𝑛)=𝑆𝐺1∙𝑆𝐺2." 
Appendix 2  
Part 1, Report,  amend to read:  
"… 
5. Tyre class:  ................................ ................................ ................................ .........   
6. Category of use:  ................................ ................................ ................................   
7. Snow grip index SG  
7.1. Test procedure and SRTT used  ................................ ................................ .........   
8. Comments (if any):  ................................ ................................ ...........................   
…" 
Part 2, Test data,  amend to read:  
" … 
5. Test results: mean fully developed decelerations (m  ∙ s-2) / traction coefficient(3) 
Run number  Specification  SRTT (1st test)  Candidate 1  Candidate 2  SRTT (2nd test)  
1      
2      
3      
4      
5      
6      
      
      
      
Mean       
Standard 
deviation       
Coefficient of 
variation  CV a ≤ 6 %     
Coefficient of 
Validation  CVal a (SRTT) 
≤ 5 %     
SRTT weighted 
average       
Factor f      
Snow grip 
index   1.00    E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 5 
 
24 (1) for C2 tyres, corresponding to the indication of the inflation pressure marked on the sidewall as 
required by paragraph 4.1. of this Regulation  
…" 
     
  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nations Regulations * 
(Revision 3, including the amendments which entered into force on 14 Septembe r 2017)  
_________  
  Addendum 116 – UN Regulation No. 117 
  Revision 4 - Amendment 6 
Supplement 14 to the 02 series of amendments  – Date of entry into force: 8 October 2022.  
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. The authentic and legal binding text is:  
ECE/TRANS/WP.2 9/2022 /8. 
_________  
UNITED NATIONS   
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, 
Equipment and Parts whic h can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision 2).   E/ECE/324/Rev. 2/Add. 116/Rev.4/Amend. 6−E/ECE/TRANS/505/Rev. 2/Add. 116/Rev. 4/Amend. 6 
   
 
23 Nove mber 2022  
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
2 Table of c ontents , Annexes,  amend to read:** 
"Annexes  
1 Communication  ................................ ................................ ................................ ................................ .....  ...........   
2 Arrangements of approval marks  ................................ ................................ ................................ ..........   ...........   
Appendix 1   Example of separate Regulation No. 117 approval marks  ................................ ......  ...........   
Appendix 2   Approval according to Regulation No. 117 coincident with  
approval of Regulation No.  30 or 54  ................................ ................................ ......  ...........   
Appendix 3  Combinations of markings approvals issued in accordance with  
Regulations Nos. 117, 30 or 54  ................................ ................................ ...............   ...........   
Appendix 4   Extensions to combine approvals issued in accordance with  
Regulation No. 117  ................................ ................................ ................................ .  ...........   
3 Coast -by test method for measuring tyre -rolling sound emission  ................................ .........................   ...........   
Appendix 1   Test report  ................................ ................................ ................................ ...............   ...........   
4 Specifications for the test site  ................................ ................................ ................................ ................   ...........   
5 Test procedures for measuring wet adhesion of new tyres  ................................ ................................ ....  ...........   
Appendix  Test reports examples of wet grip index  ................................ ................................ .  ...........   
6 Test procedure for measuring rolling resistance  ................................ ................................ ....................   ...........   
Appendix 1  Test equipment tolerances  ................................ ................................ ......................   ...........   
Appendix 2  (omitted)  ................................ ................................ ................................ .................   ...........   
Appendix 3   Test report and test data (Rolling resistance)  ................................ ..........................   ...........   
Appendix 4   Tyre standards organizations  ................................ ................................ ..................   ...........   
Appendix 5   Deceleration method: Measurements and data processing for deceleration  
value obtaining in differential form dω/dt.  ................................ .............................   ...........   
7 Procedures for snow performance testing relative to snow tyre for use in severe  snow conditions  ......  ...........   
Appendix 1  Pictogram definition of "Alpine Symbol"  ................................ ...............................   ...........   
Appendix 2   Test reports and test data for classes C1 and C2 tyres  ................................ ............   ...........   
Appendix 3   Test reports and test data for class C3 tyres  ................................ ............................   ...........   
8 Procedures for  ice performance testing relative to ice grip tyre of class C1 ................................ ..........   ...........   
Appendix 1   Pictogram definition of "Ice Grip Symbol"  ................................ ............................   ...........   
Appendix 2   Test reports and test data for class C1 tyres  ................................ ............................   ........   " 
  
  
 **  Page numbers will be indicated at a later stage (note by the secretariat) .    E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
3 Paragraph 1.1. , amend to read:  
"1.1.  This Regulation applies to new p neumatic tyres* of classes C1, C2 and C3 with 
regard to their sound emissions, rolling resistance and to adhesion performance 
on wet surfaces (wet adhesion). It does not, however, apply to:  
 
*  For the purpose of this Regulation  "tyres" means "pneumatic tyres"  
Paragraph 1.1.3. , amend to read:  
"1.1.3.  Tyres designed for competition;"  
Paragraph 1.1.6. , amend to read:  
"1.1.6.  Tyres with a speed category less than 80  km/h (speed category symbol F);"  
Paragraph 2.1. , amend to read:  
2.1. "Type of tyre " means tyres which do not differ in such essential characteristics 
as: 
(a) The manufacturer's name;  
(b) The tyre class (see paragraph 2.6. below);  
(c) The tyre structure;  
(d) The category of use: normal tyre, snow tyre  and special use tyre;  
(e) Whether snow tyre for use in severe snow conditions or not;  
(f) For class C1 tyres, whether ice grip tyre or not;  
(g) For classes C2 and C3 tyres, whether traction tyre or not;  
(h) The tread pattern (see paragraph  3.2.1. of this Regulation)."  
Paragraph 2.3. , amend to read:  
"2.3.  "Brand name/trademark " means the identification of the brand or trademark 
as defined by the tyre manufacturer and marked on the sidewall(s) of the tyre. 
The brand name/trademark may be the same as that of the manufactur er." 
Paragraphs 2.6.1. to 2.6.3. , amend to read:  
"2.6.1.  Class C1 tyres : tyres conforming to UN Regulation No.  30; 
2.6.2.  Class C2 tyres : tyres conforming to UN Regulation No.  54 and identified by a 
load capacity index in single formation lower or equal to  121 and a speed 
category symbol higher or equal to "N";  
2.6.3.  Class C3 tyres : tyres conforming to UN Regulation No.  54 and identified by:  
(a) A load capacity index in single formation higher or equal to 122; or  
(b) A load capacity index in single formati on lower or equal to 121 and a 
speed category symbol lower or equal to "M"."  
Paragraph 2.7. , amend to read:  
"2.7.  "Representative tyre size " means the tyre size which is submitted to the test 
described in Annex  3 to this Regulation with regard to rolling s ound emissions, 
or Annex  5 for adhesion on wet surfaces or Annex  6 for rolling resistance to 
assess the conformity for the type approval of the type of tyre, or Annex  7 for  
measuring snow performance, or Annex  8 for measuring ice performance."  
Paragraph 2 .11., amend to read:  
"2.11.  "Reinforced tyre " or " extra load tyre " of class C1 means a tyre structure 
designed to carry more load at a higher inflation pressure than the load carried E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
4 by the corresponding standard version tyre at the standard inflation pres sure as 
specified in ISO  4000 -1:20102" 
Paragraph 2.12. , amend to read:  
"2.12.  "Traction tyre " means a tyre in classes C2 or C3 bearing the inscription 
TRACTION and intended to be fitted primarily to the drive axle(s) of a vehicle 
to maximize force transmission in various circumstances."  
Paragraph 2.13.1. , amend to read:  
"2.13.1.  "Snow tyre for use in severe snow conditions " means a snow tyre whose tread 
pattern, tread compound or structure is specifically designed to be used in 
severe snow condition s and that fulfils the requirements of paragraphs 6.4. and 
6.4.1. of this Regulation."  
Insert a new paragraph 2.13.1.1. , to read:  
"2.13.1.1.  "Ice grip tyre " means a class C1 snow tyre for use in severe snow conditions 
that is additionally designed to be us ed on road surfaces covered with ice and 
that fulfils the requirements of paragraph 6.4.2. of this Regulation."  
Paragraph 2.18. , amend to read:  
"2.18.  "Standard Reference Test Tyre " or " SRTT " means a tyre that is produced, 
controlled and stored in accordance with the standards of ASTM International:  
(a) E1136 – 17 for the size P195/75R14 and referred to as "SRTT14",  
(b) F2493 – 20 for the size P225/60R16 and referred to as "SRTT16",  
(c) F2872 – 16 for the size 225/75R16C and referred to as "SRTT16C" , 
(d) F2871 – 16 for the size 245/70R19.5 and referred to as "SRTT19.5",  
(e) F2870 – 16 for the size 315/70R22.5 and referred to as "SRTT22.5".  
Paragraph 2.19. , amend to read:  
"2.19.  Wet adhesion or snow performance or ice performance measurements – 
Speci fic definitions"  
Paragraph 2.19.1. , amend to read:  
"2.19.1.  "Adhesion on wet surfaces " or " wet adhesion " means the relative braking 
performance, on a wet surface, of a test vehicle equipped with the candidate 
tyre in comparison to that of the same test veh icle equipped with a Standard 
Reference Test Tyre (SRTT)."  
Paragraph 2.19.2. , amend to read:  
"2.19.2.  "Candidate tyre " or "candidate tyre set " means a tyre or a tyre set, 
representative of the type that is submitted for approval in accordance with this 
Regulation and whose performances are evaluated relative to that of a 
reference tyre or reference tyre set."  
Insert a new paragraph 2.19.3. , to read:  
"2.19.3.  "Reference tyre " or " reference tyre set " means a tyre or a tyre set of Standard 
Reference Test Tyres  as defined in the respective annex."  
Paragraph 2.19.3. , renumber as 2.19.4. and amend to read:  
"2.19.4." Control tyre " or " control tyre set " means a normal production tyre or a normal 
production tyre set that is used to establish the wet adhesion level or snow 
performance level or ice performance level of tyre sizes unable to be fitted to 
the same vehicle as the reference tyre or reference tyre set – see 
paragraph  2.2.2.8. of Annex  5, part (B) , paragraph  3.4.3. of Annex  7 and 
paragraph  2.4.5.1.1. o f Annex  8 to this Regulation."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
5 Insert a new paragraph 2.19.5. , to read:  
"2.19.5.  "Test tyre" means a candidate tyre, reference tyre or control tyre."  
Paragraph 2.19.4. , renumber as 2.19.6. and amend to read:  
"2.19.6.  "Wet grip index " (G) means the dimensio nless unit for expressing the wet 
adhesion level of a candidate tyre relative to that of the applicable SRTT."  
Paragraph 2.19.5. , renumber as 2.19.7. and amend to read:  
"2.19.7.  "Snow grip index " (SG)  means the dimensionless unit for expressing the snow 
performance level of a candidate tyre relative to the performance of the 
applicable SRTT."  
Insert a new paragraph 2.19.8. , to read:  
"2.19.8 . "Ice grip index " (GI) means the dimensionless unit for expressing the ice 
performance level of a candidate tyre relat ive to the performance of the 
applicable SRTT."  
Paragraphs 2.19.6. to 2.19.8. , renumber as 2.19.9. to 2.19.11.  
Insert new paragraphs 2.19.12. to 2.19.16. , to read:  
"2.19.12.  "Test run " means a single pass of a loaded tyre over a given test surface.  
2.19.1 3. "Braking test " means a series of a specified number of test runs of the same 
test tyre repeated within a short time frame.  
2.19.14.  "Traction test " means a series of a specified number of spin -traction test runs 
of the same tyre repeated within a short time frame.  
2.19.15.  "Acceleration test " means a series of specified number of traction controlled 
acceleration test runs of the same tyre repeated within a short timeframe.  
2.19.16.  "Test cycle " means a series of braking tests, traction tests or acc eleration tests 
that consist of an initial test of the reference tyre or the control tyre, of tests of 
candidate tyres and/or control tyres and a final test of the same reference tyre 
or control tyre."  
Paragraph 2.20.1. , amend to read:  
"2.20.1.  "Rolling re sistance " (Fr) means the loss of energy (or energy consumed) per 
unit of distance travelled.3" 
Footnote 3 , amend to read:  
"3 The International System of Units (SI) unit conventionally used for the rolling resistance is the  
newton -metre per metre, which is equivalent to a drag force in newton. " 
Paragraph 2.20.2. , amend to read:  
"2.20.2.  "Rolling resistance coefficient " (Cr) means the ratio of the rolling resistance to 
the load on the tyre.4" 
Paragraph 2.20.4. , amend to read:  
"2.20.4.  "Laboratory control tyre " means a tyre used by an individual laboratory to 
control machine behaviour as a function of time.7" 
Paragraph 2.20.5. , amend to read:  
"2.20.5.  "Capped inflation " means the process  of inflating the tyre to the required cold 
inflation pressure and allowing the inflation pressure to build up, as the tyre is 
warmed up while running."  
Paragraph 2.20.6. , amend to read:  
"2.20.6.  "Parasitic loss " means the loss of energy (or energy consumed) per unit 
distance excluding internal tyre losses, attributable to aerodynamic loss of the E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
6 different rotating elements of the test equipment, bearing friction and other 
sources of systematic lo ss which may be inherent in the measurement."  
Paragraph 2.20.7. , amend to read:  
"2.20.7.  "Skim test reading " means a type of parasitic loss measurement, in which the 
tyre is kept rolling without slippage, while reducing the tyre load to a level at 
which en ergy loss within the tyre itself is virtually zero."  
Paragraph 2.20.8. , amend to read:  
"2.20.8.  "Inertia " or " moment of inertia " means the ratio of the torque applied to a 
rotating body, such as a tyre assembly or machine drum, to the rotational 
accelerati on of this body.8" 
Paragraph 2.20.9. , amend to read:  
"2.20.9.  "Measurement reproducibility " (σm) means the capability of a machine to 
measure rolling resistance.9" 
Paragraph 3.1.1. , amend to read: 
"3.1.1.  The performance characteristics to be assessed for the type of tyre; "rolling 
sound emissions level" and/or "adhesion performance level on wet surfaces" 
and/or "rolling resistance level" ; "snow performance level" in case of "snow 
tyre for use in severe snow conditions" and additionally "ice performance 
level" in case of ice grip tyre ;" 
Paragraph 3.1.5.1. , amend to read:  
"3.1.5.1.  Whether snow tyre for use in severe snow conditions or not;"  
Paragraph 3.1.5.2. , amend to read:  
"3.1.5.2.  For classes C2 and C3 tyres, whether traction tyre or not;"  
Insert a new paragraph 3.1.5.3. , to read:  
"3.1.5.3.  For class C1 tyres, whether ice grip tyre or not;"  
Paragraph 3.1.8. , amend to read:  
"3.1.8.  A list of tyre size designations covered by this application and specifying for 
each brand name/trademark and/or each trade description/commercial name 
the applicable tyre size designations and service descriptions, adding in case 
of class C1 tyres whether " reinforced" (or "extra load") or not."  
Paragraph 3.2.1. , amend to read:  
"3.2.1.  Details of the major features, with respect to the effects on the performance 
(i.e. rolling sound emission level, adhesion on wet surfaces, rolling resistance,  
snow performanc e and ice performance ) of the tyres, including the tread 
pattern, included in the designated range of tyre sizes. This may be by means 
of descriptions supplemented by technical data, drawings, photographs or 
Computer Tomography (CT) scans, and must be suff icient to allow the Type 
Approval Authority or Technical Service to determine whether any subsequent 
changes to the major features will adversely affect the tyre performance. The 
effects of changes to minor details of tyre construction on tyre performances  
will be evident and determined during checks on conformity of production;"  
Paragraph 3.2.2. , amend to read:  
"3.2.2.  Drawings or photographs of the tyre sidewall, showing the approval marks 
referred to in paragraph  4., shall be submitted once the productio n has been 
established, but no later than one year after the date of granting of type  
approval;"  
Paragraph 4.2.1. , amend to read:  
"4.2.1.  The manufacturer's name or the brand name/trademark;"  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
7 Paragraph 4.2.2. , amend to read:  
"4.2.2.  The trade description/c ommercial name (see paragraph  2.4. of this 
Regulation). However, the trade description is not required when it coincides 
with the brand name/trademark;"  
Paragraph 4.2.6. , amend to read:  
"4.2.6.  The "Alpine Symbol" ("3 -peak -mountain with snowflake" conformi ng to the  
pictogram described in Annex  7, Appendix  1) if the snow tyre is classified as 
"snow tyre for use in severe snow conditions";"  
Insert a new paragraph 4.2.6.1. , to read:  
"4.2. 6.1. The "Ice Grip Symbol" (conforming to the pictogram described in Anne x 8, 
Appendix  1) if the snow tyre for use in severe snow conditions is additionally 
classified as ice grip tyre;"  
Paragraph 4.3.1. , amend to read:  
"4.3.1.  In case the approval of a tyre pursuant to this Regulation has been granted by 
the same Type Approval  Authority than that granting the approval pursuant to 
UN Regulations Nos.  30 or  54, the approval mark pursuant to UN Regulations 
Nos. 30 or 54 can be combined with an indication of the applicable series of 
amendments to which the tyre was approved pursuan t to UN Regulation 
No. 117 on the form of 2 digits (example "02" indicating that the UN 
Regulation No.117 approval was granted following the 02 series of 
amendments) and the suffixes according to paragraph 5.2.2. using the addition 
sign "+", as described i n Annex  2, Appendix  3 of this Regulation, for example 
"0236378 + 02S1WR2"."  
Paragraph 5.2.1. , amend to read:  
"5.2.1.  Instead of granting the original type approval number pursuant to UN 
Regulation No. 117, upon the request of the manufacturer, the Type App roval 
Authority may grant the type approval number, which had been granted before 
to that type of tyre pursuant to UN Regulations Nos.  30 or 54 with the 
subsequent extension number. " 
Paragraph 5.2.2. , amend to read:  
"5.2.2.  The communication form mentioned  in paragraph 5.3. below shall identify 
specific performance parameters of UN Regulation No. 117 by the following 
suffixes: …"  
Paragraph 5.3.1. , amend to read:  
"5.3.1.  With reference to paragraph 5.2.1. above, tyre manufacturers are entitled to 
submit an a pplication for extension of type approval to the requirements of 
other Regulations relevant to the type of tyre. In that case, a copy of the 
relevant type approval communication(s), as issued by the relevant Type 
Approval Authority, shall be attached to th e application for extension of 
approval. All applications for extension of approval(s) shall only be granted by 
the Type Approval Authority which issued the original approval for the tyre."  
Paragraph 5.3.1.1. , amend to read:  
"5.3.1.1.  When extension of approval is granted to incorporate into the communication 
form (see Annex  1 to this Regulation) certification(s) of conformity to other 
Regulations, (all) the specific type approval number(s) and the Regulation 
itself shall be added to it em 9. of Annex 1 "Communication"."  
Paragraph 5.3.1.2. , amend to read:  
"5.3.1.2.  The suffix(es) mentioned in paragraph 5.2.2. above shall be preceded by the 
two digits identifying the series of amendments of the prescription on tyre 
performances for UN Regu lation No. 117, e.g. "02S2" to identify the second 
series of amendments on tyre road rolling sound emissions at stage  2 or E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
8 "02S1WR1" to identify the second series of amendments on tyre road rolling 
sound emissions at stage 1, tyre adhesion on wet surfaces and rolling resistance 
at stage  1 (see paragraph 6.1. below for stage 1 and stage 2 definitions)."  
Paragraph 5.4.3. , amend to read:  
"5.4.3.  The suffix(es), and the identification to the relevant series of amendments, if 
any, as specified in the communicati on form.  
 One of the suffixes listed below or any combination of them can be used.  
S1 Rolling sound emission level at stage 1  
S2 Rolling sound emission level at stage 2  
W Wet adhesion level  
R1 Rolling resistance level at stage 1  
R2 Rolling resistance level at stage 2  
 These suffixes shall be placed to the right or below the approval number, if 
part of the original approval.  
 If the approval is extended subsequent to UN Regulations Nos.  30 or 54 
approvals, the addition sign "+" and the serie s of amendment to UN Regulation 
No. 117 shall be placed in front of the suffix or any combination of suffixes to 
denote an extension to the approval.  
 If the approval is extended subsequent to the original approval under UN 
Regulation No.  117, the addition  sign "+" shall be placed between the suffix 
or any combination of suffixes of the original approval and the suffix or any 
combination of suffixes added to denote an extension to the approval."  
Paragraph 6.1.1. , amend to read:  
"6.1.1.  For class C1 tyres, the rolling sound emission value shall not exceed the values 
pertinent to the applicable stage given below. These values refer to the nominal 
section width as defined in UN Regulation No.  30: …"  
Paragraph 6.1.2. , amend to read:  
"6.1.2.  For class C2 tyres, the rolling sound emission value with reference to its 
category of use (see paragraph  2.1., subparagraph (d) above)  shall not exceed 
the values pertinent to the applicable stage given below: …"  
Paragraph 6.1.3. , amend to read:  
"6.1.3.  For class C3 t yres, the rolling sound emission value with reference to its 
category of use (see paragraph  2.1., subparagraph (d) above) shall not exceed 
the values pertinent to the applicable stage given below: …"  
Paragraph 6.2. , amend to read:  
"6.2.  The wet adhesion wi ll be based on a procedure that compares either peak brake 
force coefficient ("pbfc") or mean fully developed deceleration ("mfdd") 
against values achieved by a Standard Reference Test Tyre (SRTT). The 
relative performance shall be indicated by a wet grip index  (G)."  
Paragraph 6.2.1. , amend to read:  
"6.2.1.  For class C1 tyres, tested in accordance with either procedure given in Annex 
5, Part (A), to this Regulation, the tyre shall meet the following requirements:  
Category of use   Wet grip index 
(G) 
Normal tyre  ≥ 1.1  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
9 Category of use   Wet grip index 
(G) 
Snow tyre  ≥ 1.1  
"Snow tyre for use in severe snow conditions" 
and with a speed category symbol ("R" and 
above, including  "H") indicating a maximum 
permissible speed greater than  160 km/h  ≥ 1.0  
"Snow tyre for use in severe snow conditions" 
and with a speed category symbol ("Q" or 
below excluding  "H") indicating a maximum 
permissible speed not greater than  160 km/h  ≥ 0.9  
Special use tyre  Not defined  
" 
Paragraph 6.2.2. , amend to read:  
"6.2.2.  For class C2 tyres, tested in accordance with either procedure given in 
Annex  5, Part (B), to this Regulation, the tyre shall meet the following 
requirements: …"  
Paragraph 6.2.3. , amend to read:  
"6.2.3.  For class C3 tyres, tested in accordance wit h either procedure given in 
Annex  5, Part (B), to this Regulation, the tyre shall meet the following 
requirements: …"  
Paragraphs 6.4.1. and 6.4.1.1. , merge and amend to read:  
"6.4.1.  Snow performance requirements for classes C1, C2 and C3 tyres  
 The minimum snow grip index value, as calculated in the procedure described 
in Annex 7 and compared with the respective Standard Reference Test Tyre 
(SRTT) shall be as follows: …"  
Insert a new paragraph 6.4.2. , to read:  
"6.4.2.  Ice performance requirements for  class C1 tyres classified as ice grip tyre  
In order to be classified as ice grip tyre, a snow tyre for use in severe snow 
conditions shall meet the minimum ice grip index value, as calculated in the 
procedure described in Annex 8 and compared with the res pective Standard 
Reference Test Tyre (SRTT) shall be as follows:  
Class of tyre  Ice grip index  
 Ref. = SRTT16  
C1 1.18 
 " 
Paragraph 6.5. , amend to read:  
"6.5.  In order to be classified as a "traction tyre", a tyre is required to meet the 
condition of paragraph  6.5.1. below."  
Paragraph 6.5.1. , amend to read:  
"6.5.1.  The tyre shall have a tread pattern with minimum two circumferential ribs, 
each containing a minimum of 30 block -like elements, separated by grooves 
and/or sipe elements the depth of which has to be minimum of one half of the 
tread depth. The use of an alternative option of a physical test will only apply 
at a later stage following a further amendment to the Regulation including a 
reference to appropriate test methods and limi t values."  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
10 Paragraph 6.6. , amend to read:  
"6.6.  In order to be classified as a "special use tyre" a tyre shall have a block tread 
pattern in which the blocks are larger and more widely spaced than for normal 
tyres and have the following characteristics:  
For class C1 tyres: a tread depth ≥ 11 mm and void to fill ratio ≥ 35  per cent;  
For class C2 tyres: a tread depth ≥ 11 mm and void to fill ratio ≥ 35  per cent;  
For class C3 tyres: a tread depth ≥ 16 mm and void to fill ratio ≥ 35  per cent."  
Paragraph 6.7. , amend to read:  
"6.7.  In order to be classified as a "professional off -road tyre", a tyre shall have all 
of the following characteristics:  
 (a) For classes C1 and C2 tyres:  
  (i) A tread depth ≥ 11 mm;  
  (ii) A void -to-fill ratio ≥ 35 per cent;  
  (iii) A maximum speed rating category symbol of ≤ Q.  
 (b) For class C3 tyres:  
  (i) A tread depth ≥ 16 mm;  
  (ii) A void -to-fill ratio ≥ 35 per cent;  
  (iii) A maximum speed category symbol of ≤ K."  
Paragraph 8. , amend to read:  
 "… The conformi ty of production procedures shall comply with those set out 
in the 1958 Agreement, Schedule 1 (E/ECE/324 -E/ECE/TRANS/505/Rev.3) 
with the following requirements:"  
Paragraph 8.2. , amend to read:  
"8.2.  The authority which has granted type approval may at any time verify the 
conformity control methods applied by the manufacturer. In general, the 
conformity control methods should take into consideration the production 
volumes of the type of tyre at each manufacturing facility. The normal 
frequency of these verif ications shall be at least once every two years."  
Insert a new paragraph 8.3. , to read:  
"8.3.  Verification tests shall be carried out on random samples of tyres bearing the 
approval mark required by this Regulation taken from the series production. 
Where t he test procedure involves testing a number of tyres at the same time, 
for example a set of four tyres for the purpose of measuring wet adhesion in 
accordance with the standard vehicle procedure given in Annex  5 to this 
Regulation, then the set shall be co nsidered as being one unit for the purposes 
of calculating the number of tyres to be tested. The Type Approval Authority 
shall satisfy itself that all tyres falling within an approved type comply with 
the approval requirement."  
Paragraph 8.2.1. , renumber a s 8.3.1. and amend to read:  
"8.3.1.  In the case of verification tests with regard to approvals in accordance with 
paragraph  6.2. of this Regulation, these shall be carried out using the same 
testing method (see  Annex  5 to this Regulation) as that adopted f or original 
approval."  
Insert a new paragraph 8.3.2. , to read:  
"8.3.2.  In the case of verification tests with regard to approvals in accordance with 
paragraph  6.4. of this Regulation, these shall be carried out using the same E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
11 testing method (see  Annex  7 to this Regulation) as that adopted for original 
approval."  
Paragraphs 8. 3. and 8.4. , renumber as 8.4. and 8.5. , respectively.  
Paragraph 9.1. , amend to read:  
"9.1. The approval granted in respect of a type of tyre pursuant to this Regulation 
may be withdrawn if the requirements laid down in paragraph  8. above are not 
complied with, or if any tyre of the type of tyre exceeds the limits given in  
paragraphs 8.4. or 8.5 . above. " 
Paragraph 12.1. , amend to read:  
"12.1.  As from the date of entry into force of the 02  series of amendments to this 
Regulation, Contracting Parties applying this Regulation shall not refuse to 
grant approval under this Regulation for a type of tyr e if the tyre complies with 
the requirements of the 02 series of amendments, including the stage  1 or stage 
2 rolling sound requirements set out in paragraphs  6.1.1. to  6.1.3. of this 
Regulation, the requirements for wet adhesion set out in paragraph  6.2.1 . of 
this Regulation, and the stage  1 or stage 2 rolling resistance requirements set 
out in paragraph  6.3.1. or 6.3.2. of this Regulation."  
Paragraph 12.2. , amend to read:  
"12.2.  As from 1 November 2012, Contracting Parties applying this Regulation shall 
refuse to grant approval if the type of tyre to be approved does not meet the 
requirements of this Regulation as amended by the 02 series of amendments, 
and shall, in addition, refuse to grant approval if the stage  2 rolling sound 
requirements set out in pa ragraphs  6.1.1. to  6.1.3.  of this Regulation , the 
requirements for wet adhesion set out in paragraph  6.2.1. of this Regulation, 
and the stage  1 rolling resistance requirements set out in paragraph  6.3.1. of 
this Regulation  are not complied with."  
Paragraph  12.3. , amend to read:  
"12.3.  As from 1 November 2014, Contracting Parties applying this Regulation may 
refuse to allow the sale or entry into service of a tyre which does not meet the 
requirements of this Regulation as amended by the 02 series, and which does 
not meet the requirements of this Regulation as amended by the 02 series of 
amendments including the wet adhesion requirements set out in 
paragraph  6.2.1.  of this Regulation."  
Paragraph 12.4. , amend to read:  
"12.4.  As from 1  November 2016, Contracting  Parties applying this Regulation shall 
refuse to grant approvals if the type of tyre to be approved does not meet the 
requirements of this Regulation as amended by the 02  series of amendments 
including the stage 2 rolling resistance requirements set out i n paragraph  6.3.2. 
of this Regulation and the wet adhesion requirements set out in paragraphs 
6.2.2. and 6.2.3. of this Regulation."  
Paragraph 12.7. , amend to read:  
"12.7.  As from the dates given below, any Contracting Party applying this Regulation 
may re fuse to allow the sale or entry into service of a tyre which does not meet 
the requirements of this Regulation as amended by the 02  series, and which 
does not meet the stage 2 rolling resistance requirements set out in 
paragraph  6.3.2. of this Regulation a nd the wet adhesion requirements set out 
in paragraphs 6.2.2. and 6.2.3. of this Regulation:  
Tyre class  Date  
C1 and C2  1 November 2018  
C3 1 November 2020  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
12  " 
Paragraph 12.12. , amend to read:  
"12.12.  Until 1 September 2024, Contracting Parties applying this Regulation may 
continue to grant type approvals according to the 02 series of amendments to 
this Regulation, based on the test procedures for measuring wet adhesion 
described in Annex 5 of this Regulation, without taking into account the 
provisions of Supplement 13."  
Insert a new paragraph 12.13. , to read:  
"12.13.  Until 3 months after the date of entry into force of Supplement 14 to the 02 
series of amendments to this Regulation, Contracting Parties applying this 
Regulation can continue to gra nt type approvals according to the 02 series of 
amendments to this Regulation, without taking into account the provisions of 
Supplement 14."  
Annex 1 ,  
Insert a new item 4.1.1. , to read:  
"4.1.1.    Ice grip tyre (Yes/No)2" 
Item 6. , amend to read:  
"6.   Type of tyre designation:"  
Item 6.2. , amend to read:  
"6.2.    Trade description(s)/commercial name(s) of the type of tyre: "  
  Item 8.2., amend to read:  
"8.2.  Wet adhesion level of the representative tyre size, see paragraph 2.7. of this 
Regulation, as per the test report examples shown in the appendix to Annex  5: 
……………………… (G) using the vehicle or trailer method2" 
Item 8.4. , amend to read:  
"8.4.  Snow performance level of the representative tyre size, see paragraph 2.7. of 
Regulation No. 1 17, as per item 7. of the test report in the appendix5 to 
Annex  7:………………. (snow grip index) using the brake on snow method2, 
spin traction method2 or acceleration method.2" 
Insert a new item 8.4.1. , to read:  
"8.4.1. Ice performance level of the representat ive tyre size, see paragraph 2.7. of 
Regulation No. 117, as per item 7. of the test report in the appendix 2 to 
Annex  8:…………………….…(ice grip index) using the brake on ice 
method.2" 
Footnote 5. , amend to read:  
"5 Appendix 2 for classes C1 and C2 tyres.  
Appen dix 3 for class C3 tyres."  
Item 16.2. , amend to read:  
"16.2.  A list of tyre size designations: Specify for each brand name/trademark and/or 
each trade description/commercial name the list of tyre size designations and 
service descriptions, adding in case o f class C1 tyres whether "reinforced" (or 
"extra load") or not."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
13 Annex 2  
Title, amend to read:  
"Annex 2  
  Arrangements of approval marks"  
Annex 2 - Appendix 1 , amend to read:  
"Annex 2 - Appendix 1  
  Examples of separate UN Regulation No. 117 approval marks  
Approval according to UN Regulation No.  117 (see paragraph  5.4. of this Regulation)  
  Example 1  
 
The above approval mark, affixed to a tyre shows that a tyre concerned has been 
approved in the Netherlands (E  4) pursuant to Regulation No.  117 (marked by "S2"), under 
approval number 0212345. This indicates that the approval is for rolling sound at stage 2 
(S2). The first two digits of the approval number (02) indicate that the approval was granted 
in accordance wit h this Regulation which included 02 series of amendments.  
  Example 2  
 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to Regulation No.  117 (marked by "S1WR1") under approval 
number 0212345. This indicates that the approval is for rolling sound at stage 1 (S1), wet 
adhesion (W) and rolling resistance at stage 1 (R1). The first two digits of the approval 
number ("02") indicate that the approval was granted in accordance  with this Regulation 
which included the 02  series of amendments."  
0212345 S2  
0212345 S1WR1  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
14 Annex 2 - Appendix 2 , delete footnote 1 and amend to read:  
"Annex 2 - Appendix 2  
  Approval according to UN Regulation No. 117 coincident 
with approval of UN Regulation s Nos. 30 or 54  
  Example 1  
 
            a/3      0212345 S2   0236378  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to UN Regulation No.  117 (marked by "S2"), under approval 
number  0212345 and UN Regulation No.  30, under approval number  0236378.  This 
indicates that  the approval is for rolling sound at stage 2 (S2). The first two digits of the 
approval number ("02") in conjunction with "S2" indicate that the approval was granted in 
accordance with UN Regulation No. 117 which included the 02 series of amendments. The 
first two digits of the UN Regulation No.  30 approval number ("02") indicate that this 
Regulation included the 02 series of amendments.  
Example 2  
 
0212345 S2WR2   0236378  
or 
0212345 S2WR2  
0236378  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to UN Regulation No.  117 (marked by "S2WR2"), under 
approval number 0212345 and UN Regulation No.  30, under approval number 0236378. This 
indicates th at the approval is for rolling sound at stage 2 (S2), wet adhesion (W) and rolling 
resistance at stage 2 (R2). The first two digits of the approval number ("02") in conjunction 
with "S2WR2" indicate that the first approval was granted in accordance with UN Regulation 
No. 117 which included the 02 series of amendments. The first two digits of the UN 
Regulation No.  30 approval number ("02") indicate that this Regulation included the 02 series 
of amendments.  
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
15   Example 3  
 
           a/3     0212345 S2   0054321  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to  UN Regulation No.  117 and the 02 series of amendments under 
approval number 0212345 (marked by "S2"), and UN Regulation No.  54, under appro val 
number 0054321. This indicates that the approval is for rolling sound stage  2 (S2). The first 
two digits of the UN Regulation No.  117 approval number ("02") in conjunction with "S2" 
indicate that the first approval was granted in accordance with UN Regulation No.  117 which 
included the 02 series of amendments. The first two digits of the UN Regulation No.  54 
approval number ("00") indicate that this Regulation was in its original form.  
  Example 4  
 
a/3     0212345 S2R2   0054321  
The above approval mar k shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to UN Regulation No.  117 and the 02 series of amendments under 
approval number 0212345 (marked by "S2R2"), and UN Regulation No.  54, under approval 
number 0054321. This ind icates that the approval is for rolling sound stage 2 (S2) and rolling 
resistance stage  2 (R2). The first two digits of the UN Regulation No.  117 approval number 
("02") in conjunction with "S2R2" indicate that the first approval was granted in accordance 
with UN Regulation No.  117 which included the 02  series of amendments. The first two 
digits of the UN Regulation No.  54 approval number ("00") indicate that this Regulation was 
in its original form."  
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
16 Annex 2 - Appendix 3 , amend to read:  
"Annex 2 - Appendix 3  
  Combinations of markings of approvals issued in accordance 
with UN Regulations Nos. 117, 30 or 54  
Example 1  
 
         a/3    0236378 + 02S1  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pur suant to UN Regulation No.  30 according to its 02 series of 
amendments (indicated by the first two digits of the approval number, "02") under approval 
number 0236378. It is also marked by "+ 02S1" which indicates that the tyre was also 
approved pursuant to  UN Regulation No.  117 (02 series of amendments) for rolling sound at 
stage 1.  
Example 2  
 
    a/3      0236378 + 02S1WR2  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E  4) pursuant to Regulation No.  30 according to its 02 series of amendments 
(indicated by the first two digits of the approval number, "02") under approval number 
0236378. It is also marked by "+  02S1WR2" which indicates that the tyre was also approved 
pursuant to UN Regulation No.  117 (02 series of amendments) for S1 (rolling sound at 
stage  1), W  (wet adhesion) and R2 (rolling resistance at stage 2)."  
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
17 Annex 2 - Appe ndix 4 , delete footnote 1 amend to read:  
"Annex 2 - Appendix 4  
  Extensions to combine approvals issued in accordance with 
Regulation No. 117 
  Example 1  
 
    a/3      0212345 W + S2R2  
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E  4) pursuant to UN Regulation No.  117 according to its 02 series of 
amendments (indicated by the first two digits of the approval number, "02") under app roval 
number 0212345 (marked by "W"). This indicates that the approval is for W (wet adhesion). 
The "S2R2" preceded by "+" indicates that its approval has been extended under UN 
Regulation No.  117 to rolling sound at stage 2 and rolling resistance at stage  2 based on 
separate certificate(s).  
  Example 2  
 
    a/3      0212345 S1W + R1  
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E  4) pursuant to UN Regulation No.  117 according to its 02 series of 
amendments (indicated by the first two digits of the approval number, "02") under approval 
number 0212345 (marked by "S1W"). This indicates that the approval is for S1 (rolling sound 
at stage  1) and W (wet adhesion). The "R1" preceded by "+" indicates that  its approval has 
been extended under Regulation No.  117 to rolling resistance at stage  1 based on separate 
certificate(s).  
  Example 3  
 
    a/3      0167890 SW + 02R1  
The above approval mark shows that the tyre concerned has been initially approved 
in th e Netherlands (E  4) pursuant to UN Regulation No.  117 according to its 01 series of 
amendments (indicated by the first two digits of the approval number, "01") under approval 
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
18 number 0167890 (marked by "SW"). This indicates that the approval is for S (rolli ng sound 
at stage  1) and W (wet adhesion). The "02R1" preceded by "+" indicates that  its approval has 
been extended under UN Regulation No.  117 according to its 02 series of amendments to 
rolling resistance at stage  1 based on separate certificate(s). " 
Annex 3,  
Paragraph 2.4.3. , amend to read:  
"2.4.3.  Wheelbase  
 The wheelbase between the two axles fitted with the test tyres shall for class C1 be 
less than 3.50 m and for class C2 and class C3 tyres be less than 5  m." 
Paragraph 2.5.1. , amend to read:  
"2.5.1.  General  
 Four identical tyres shall be fitted on the test vehicle. In the case of class C3 
tyres with a load capacity index in excess of 121 and without  any dual fitting 
indication, two of these tyres of the same type and range shall be fitted to t he 
rear axle of the test vehicle; the front axle shall be fitted with tyres of size 
suitable for the axle load and planed down to the minimum depth in order to 
minimize the influence of tyre/road contact noise while maintaining a 
sufficient level of safety . 
In the case of class C2 tyres with a load capacity index lower or equal to 121, 
with a section width wider than 200 mm, an aspect ratio lower than 55, a rim 
diameter code lower than 15 and without any dual fitting indication, two of 
these tyres of the same type and range shall be fitted to the rear axle of the test 
vehicle; the front axle shall be fitted with tyres of a size suitable for the axle 
load and planed down to the minimum depth in order to minimize the influence 
of tyre/road contact noise whil e maintaining a sufficient level of safety.  
Tyres with special fitting requirements shall be tested in accordance with these 
requirements (e.g. rotation direction). The tyres shall have full tread depth 
before being run -in. 
Tyres are to be tested on rims p ermitted by the tyre manufacturer."  
Paragraph 2.5.3. , amend to read:  
"2.5.3.  Tyre inflation pressure  
 Each tyre fitted on the test vehicle shall have a test pressure P t not higher than 
the reference pressure P r and within the interval:  
25. 1
rt
r t25. 1
rt
rQQP 1 . 1 PQQP


  



 
 
For class C2 and class C3 the reference pressure P r is the inflation pressure 
corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation.  
 For class C1 the reference pressure is P r = 250 kPa for "standard" tyres 
and 290 kPa for "reinforced" or "extra load" tyres; the minimum test pressure 
shall be P t = 150 kPa."  
Paragraph 3.3. , amend to read:  
"3.3.  Test speed range  
 The test vehicle speeds shall be within the range:  
 (a) From 70 to 90 km/h for class C1 and class C2 tyres;  
 (b) From 60 to 80 km/h for class C3 tyres."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
19 Paragraph 4. , amend to read:  
"4. Interpretation of results  
 The measurement shall be invalid if an abnormal discrepancy between the 
values is recorded (see paragraph  2.3.2. of this Annex)."  
Paragraph 4.1. , amend to read:  
"4.1.  Determination of test result  
 Reference speed V ref used to determine the final result will be:  
 (a) 80 km/h for class C1 and class C2 tyres;  
 (b) 70 km/h for class C3 tyres."  
Paragraph 4.2., amend to read:  
"4.2.  Temperature correction  
 For class C1 and class C2 tyres, the rolling sound levels Li(i) obtained at the 
test surface temperature i (where i denotes the number of the single 
measurement) shall be normalized to a test surface reference temperature ref 
by applying a temperature correction, according to the following formula:  
𝐿𝑖(𝜗ref)=𝐿𝑖(𝜗𝑖)+𝐾(𝜗ref−𝜗𝑖) 
where:  
 ref = 20 °C,  
 For class C1 tyres, the coefficient K is: 
−0.03 dB(A)/°C  when i > ref and 
−0.06 dB(A)/°C  when i < ref. 
 For class C2 tyres, the coefficient K is − 0.02 dB(A)/°C.  
 Notwithstanding the above procedure, the temperature correction may be made 
only on the final reported tyre rolling sound level LR, utilizing the arithmetic 
mean value of the measured temperatures, if the measured test surface 
temperature does not change m ore than  5 °C within all measurements 
necessary for the determination of the sound level of one set of tyres. In this 
case the regression analysis below shall be based on the uncorrected rolling 
sound levels Li(i). 
 There will be no temperature correction  for class C3 tyres."  
Annex 3 – Appendix 1  
Part 1, item 6.1. , amend to read:  
"6.1.  Snow tyre  use in severe snow conditions (Yes/No)1  ................................ ....................  " 
Part 2, item 2. , amend to read:  
"2. Test vehicle (make, model, year, modifications, etc.):  ................................ .................   
  ................................ ................................ ................................ ................................ ...... " 
Part 2, item 5.2. , amend to read:  
"5.2.  Sound level according to paragraph 4.3. of Annex 3:  
  ................................ ................................ ................................ ........................  dB(A)"  
Footnote 2, amend to read:  
"2 for classes C2 and C3 tyres, corresponding to the indication of the inflation pressure 
marked on the sidewall as required by paragraph 4.1. of this Regulation"  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
20 Annex 4 , 
Paragraph 2.1. , amend to read:  
"2.1.  Residual voids content  
 The residual Voids Content (VC) of the test track paving mixture shall not 
exceed 8  per cent. For the measurement procedure, see paragraph  4.1. of this 
Annex."  
Paragraph 4.1. , amend to read:  
"4.1.  Measurement of the residual voids content  
 For the purpose of this measurement, cores have to be taken from the track in 
at least four different positions, which are equally distributed in the test area 
between lines  AA and BB (see Figure  1). In order to avoid in homogeneity and 
unevenness in the wheel tracks, cores should not be taken in wheel tracks 
themselves, but close to them. T wo cores (minimum) should be taken close to 
the wheel tracks and one core (minimum) should be taken approximately 
midway between the wheel tracks and each microphone location.  
 If there is a suspicion that the condition of homogeneity is not met 
(see parag raph 2.4. above), cores shall be taken from more locations within the 
test area.  
 The residual voids content has to be determined for each core, then the average 
value from all cores shall be calculated and compared with the requirement of 
paragraph  2.1. o f this Annex. In addition, no single core shall have a voids 
value, which is higher than 10  per cent.  
 The test surface constructor is reminded of the problem , which may arise when 
the test area is heated by pipes or electrical wires and cores shall be tak en from 
this area. Such installations shall be carefully planned with respect to future 
core drilling locations. It is recommended to leave a few locations of size 
approximately 200  mm x 300  mm where there are no wires/pipes or where the 
latter are located  deep enough in order not to be damaged by cores taken from 
the surface layer."  
Annex 5  
Title,  amend to read:  
"Annex 5  
  Test procedures for measuring the wet grip index adhesion of 
new tyres " 
Part (A), title, amend to read:  
  "(A) — Class C1 tyres"  
Paragraph 2. , amend to read:  
"2.  Definitions  
In addition to the definitions in paragraph 2. of the main body of this 
Regulation, for the purposes of measuring wet adhesion of class C1 tyres:"  
Paragraphs 2.1. to 2.5 , delete.  
Paragraph 2.6. , renumber as 2.1 . and amend to read:  
"2.1.  "Reference tyre " or "reference tyre set " means a tyre or a tyre set of Standard 
Reference Test Tyres SRTT16."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
21 Paragraph 2.7. , renumber as 2.2.  
Paragraph 2.8. , renumber as 2.3. and amend to read:  
"2.3.  "Average braking force coeff icient " (BFC) means, for the vehicle method, the 
ratio of the average deceleration in a braking test to the acceleration due to 
gravity (rounded to 9.81  m∙s−2)." 
Paragraphs 2.9. to 2.15. , renumber as 2.4. to 2.10 . 
Paragraph 3.1.5. , amend to read:  
"3.1.5.  The wetted frictional properties of the surface shall be measured using the 
SRTT16 either with the method described in paragraph 3.2.1. of this Annex in 
case the vehicle method (according to paragraph 4.1. below) is used, or with 
the method described in par agraph 3.2.2. in this Annex in case the trailer (or 
tyre test vehicle) method is used."  
Paragraph 3.2.1. , amend to read:  
"3.2.1.  Using the procedure described in paragraph  4.1. of this Annex, perform two 
braking tests of the reference tyre, each consisting  of at least six (6) valid test 
runs in the same direction on aligned segments of the track. The braking tests 
shall cover the entire potential braking area, including where the texture depth 
was measured.  
Evaluate the braking tests as described in paragraphs  4.1.6.1. and 4.1.6.2. of 
this Annex. If the coefficient of variation of one braking test CV BFC exceeds 
4 per cent, dismiss the results and repeat the braking tests.  
For each braking test, the arithmetic  mean 𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅ of the average braking force 
coefficients shall be corrected for effects of temperature as follows:  
𝐵𝐹𝐶 ave,corr =𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
where  
ϑ is the wetted surface temperature in degrees Celsius,  
𝑎= 0.002  ℃−1 and 𝜗0=20 ℃ . 
For each braking test, the temperature -corrected average braking force 
coefficient ( BFC ave,corr ) shall be not less than 0.57 and not greater than 0.79.  
The arithmetic means of the temperature -corrected average braking force 
coefficients of the two braking tests sha ll not differ by more than 10  per cent 
of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 ave,corr )=2∙|𝐵𝐹𝐶 ave,corr,1 −𝐵𝐹𝐶 ave,corr,2
𝐵𝐹𝐶 ave,corr,1 +𝐵𝐹𝐶 ave,corr,2|≤10 % 
" 
Paragraph 4. , amend to read:  
"4. Testing methods for measuring wet adhesion  
 For the  calculation of the wet grip index (G) of a candidate tyre, the wet grip 
braking performance of the candidate tyre is compared to the wet grip braking 
performance of the reference tyre on a vehicle travelling straight ahead on a 
wet, paved surface. It is m easured with one of the following methods:  
(a) Vehicle method consisting of testing a set of tyres mounted on an 
instrumented passenger car;  
(b) Testing method using a trailer towed by a vehicle or a tyre test vehicle, 
equipped with the test tyre(s)."  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
22 Paragraph 4.1.1. , amend to read:  
"4.1.1.  Principle  
 The testing method covers a procedure for measuring the deceleration 
performance of class C1 tyres during braking, using an instrumented passenger 
car. 
  Starting with a defined initial speed, the brakes are applied hard enough on 
four wheels at the same time to activate the ABS. The average deceleration is 
calculated between two pre -defined speeds."  
Paragraph 4.1.6.1. , amend to read:  
"4.1.6.1.  Calculation of the average braking force coe fficient  
 For each valid test run j, the average braking force coefficient BFC ave,j is 
calculated from the distance dj covered between 80  km/h and 20  km/h as 
follows:  
𝐵𝐹𝐶 𝑎𝑣𝑒 ,𝑗=𝑣𝑖2−𝑣𝑓2
2∙𝑑𝑗∙𝑔 
 where:  
vf is the final speed  in m/s; vf = 20 km/h = 5.556 m/s 
vi is the initial speed in m/s; vi = 80 km/h = 22.222 m/s 
dj is the distance covered  in test run j between vi and vf in metres;  
g is the acceleration due to gravity = 9.81 m∙s−2." 
Paragraph 4.1.6.2. , amend to read:  
"4.1.6.2.  Validation  of results  
 The coefficient of variation CV BFC is calculated as follows:  
𝐶𝑉𝐵𝐹𝐶 =100% ∙𝜎𝐵𝐹𝐶
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅ 
where  
 𝜎𝐵𝐹𝐶 =√1
𝑁−1∑ (𝐵𝐹𝐶 𝑎𝑣𝑒 ,𝑗−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample 
standard deviation and  
𝐵𝐹𝐶𝑎𝑣𝑒̅̅̅̅̅̅̅̅  the arithmet ic mean of the average  braking force coefficients BFC ave,j 
of N test runs.  
 For the reference tyre:  
(a) The coefficient of variation CV BFC of the initial and the final braking 
test of the reference tyre within one test cycle shall be less than or equal 
to 4 per cent.  
(b) The arithmetic means of the average braking force coefficients  of the 
initial and the final braking test shall not differ by more than 5  per cent 
of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 𝑎𝑣𝑒)=100% ∙ 2∙|𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)|≤5% 
where  
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri) / 𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf) is the arithmetic mean of the average  braking 
force coefficients  in the initial/final braking test of the reference tyre 
within a test cycle.  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
23 (c) The temperature -corrected average b raking force coefficients  
(BFC ave,corr , see paragraph  3.2.1. of this Annex ) as calculated from the 
initial and from the final braking tests of the reference tyre within a test 
cycle shall be not less than 0.57 and not greater than 0.79.  
If one or more of the above conditions is not met, the complete test cycle shall 
be performed again.  
 For the candidate tyres (T):  
  The coefficient of variation CV BFC is calculated for each candidate tyre set. If 
one coefficient of variation is higher than 4 per cent, the data shall be discarded 
and the braking test repeated for that candidate tyre set."  
Paragraph 4.1.6.3. , amend to re ad: 
"4.1.6.3.  Calculation of adjusted average braking force coefficient  
 The average braking force coefficient of the reference tyre set used for the 
calculation of its braking force coefficient is adjusted according to the 
positioning of each candidate ty re set in a given test cycle.  
 This adjusted average braking force coefficient of the reference tyre 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅) 
is calculated in accordance with Table 1 where 𝐵𝐹𝐶𝑎𝑣𝑒̅̅̅̅̅̅̅̅(𝑅𝑖) is the arithmetic 
mean of the average braking force coefficients in the ini tial braking test of the 
reference tyre set (R i) and 𝐵𝐹𝐶𝑎𝑣𝑒̅̅̅̅̅̅̅̅(𝑅𝑓) is the arithmetic mean of the average 
braking force coefficients in  the final braking test of the same reference tyre 
set (R f) within the test cycle.  
Table 1  
If the number and the sequen ce 
of candidate tyre sets within one 
test cycle is:  and the candidate tyre 
set to be qualified 
within this test cycle is:  the corresponding adjusted average braking force coefficient  of the 
reference tyre is calculated as follows:  
1 Ri – T1 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=12⁄∙[𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓)] 
2 Ri – T1 – T2 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=23⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+13⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
T2 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=13⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+23⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
3 Ri – T1 – T2 – T3 – Rf T1 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=34⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+14⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
T2 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=12⁄∙[𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓)] 
T3 𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)=14⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑖)+34⁄∙𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅(𝑅𝑓) 
" 
Paragraph 4.1.6.4. , amend to read:  
"4.1.6.4.  Calculation  of the wet grip index of the candidate tyre  
 The wet grip index G(Tn) of the candidate tyre T n (n = 1, 2 or 3) is calculated 
as follows:  
𝐺(T𝑛)=𝐾vehicle ∙{𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛)−[𝑎∙∆𝐵𝐹𝐶 (R)+𝑏∙∆𝜗+𝑐∙(∆𝜗)2+𝑑∙∆𝑀𝑇𝐷 ]} 
where : 
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛) is the arithmetic mean of the average  braking force coefficients 
of the candidate tyre T n within a braking test;  
∆𝐵𝐹𝐶 (𝑅)=𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)−𝐵𝐹𝐶 (𝑅0) 
BFC adj(R) is the adjusted average braking force coefficient in accordance  
with Table  1; E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
24 BFC (R0)  = 0.68  is fixed as the braking force coefficient  for the reference 
tyre in the reference conditions ; 
∆𝜗=𝜗−𝜗0 
ϑ is the measured wet surface temperature in degrees Celsius when 
the candidate tyre T n is tested;  
ϑ0 is the wetted surface reference temperature for the candidate tyre 
according to its category of use as listed in Table  2; 
∆𝑀𝑇𝐷 =𝑀𝑇𝐷 −𝑀𝑇𝐷 0 
MTD  is the measured macro texture depth in mm of the track (see 
paragraph  3.1.4. of this Annex);  
MTD 0 = 0.8  mm is the macro texture depth of th e reference track;  
Kvehicle  = 1.87  is a factor to grant consistency between previous calculation of 
the wet grip index and this one, and to ensure convergence 
between vehicle and trailer method and  
coefficients a, b, c and d are given in Table  2. 
Table  2 
Category of use  ϑ0 
(°C) a 
 b 
(°C−1) c 
(°C−2) d 
(mm−1) 
Normal tyre  20 +0.99382  +0.00269  −0.00028  −0.02472  
Snow tyre  15 +0.92654  −0.00121  −0.00007  −0.04279  
 Snow tyre for use in 
severe snow conditions  10 +0.72029  −0.00539  +0.00022  −0.03037  
Special -use tyre  not defined  
" 
Paragraph 4.2.4.2. , amend to read:  
"4.2.4.2.  For "self -watering" systems, the  tow vehicle and trailer or the tyre test vehicle 
may be optionally equipped with a pavement -wetting system, less the storage 
tank, which, in the case of the trailer, is mounted on the tow vehicle. The water 
being applied to the pavement ahead of the test tyre s shall be supplied by a 
nozzle suitably designed to ensure that the water layer encountered by the test 
tyre has a uniform cross section at the test speed with a minimum splash and 
overspray.  
 The nozzle configuration and position shall ensure that the wa ter jets are 
directed towards the test tyre and pointed towards the pavement at an angle of 
20° to 30°.  
 The water shall strike the pavement 250 mm to 450 mm ahead of the centre of 
tyre contact. The nozzle shall be located 25 mm above the pavement or at th e 
minimum height required to clear obstacles which the tester is expected to 
encounter, but in no case more than 100 mm above the pavement.  
 The water layer shall be at least 25 mm wider than the test tyre tread and 
applied so the tyre is centrally located  between the edges. Water delivery rate 
shall ensure a water depth of (1.0 ± 0.5) mm and shall be consistent throughout 
the test to within ±10 per cent. The volume of water per unit of wetted width 
shall be directly proportional to the test speed. The quan tity of water applied 
at 65 km/h shall be 18  l/s per metre  of width of wetted surface in case of a 
water depth of 1.0 mm."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
25 Paragraph 4.2.7.1.4. , amend to read:  
"4.2.7.1.4.  The brakes shall be activated within an area of six (6)  metres  in the longitudinal 
direction and 0.5  metres  in the transversal direction of a measurement point of 
the wetted frictional properties of the surface and sand depth in accordance 
with paragraphs  3.1.4. and 3.1.5. above. The test shall be run in the same 
direction as in paragraph  3.2.2. of this Annex. The rate of braking application 
shall be such that the time interval between initial application of force and peak 
longitudinal force is in the range 0.2 s to 0.5 s."  
Paragraph 4.2.8.2. , amend to read:  
"4.2.8.2.  Validation of results  
 The µpeak coefficient of variation CV µ is calculated as follows:  
𝐶𝑉𝜇=100% ∙𝜎𝜇
𝜇peak̅̅̅̅̅̅ 
where  
𝜎µ=√1
𝑁−1∑ (𝜇peak ,𝑗−𝜇peak̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample standard 
deviation and  
𝜇peak̅̅̅̅̅̅ the arithmetic mean of the peak braking force  coefficients ( 𝜇peak ,𝑗) of N 
test runs.  
 For the reference tyre (R):  
(a) The coefficients of variation CV μ of the initial and the final braking tests 
of the reference tyre within one test cycle shall be less than or equal to 
4 per cent;  
(b) The arithmetic mean of the peak braking force coefficients of initial and 
the final braking test of the reference tyre wi thin one test cycle shall not 
differ by more than 5  per cent of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝜇𝑝𝑒𝑎𝑘 )=100% ∙2∙|𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)−𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)|≤5 % 
where  
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri) and 𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) are the arithmetic means of the peak 
braking force coefficients respectively in the initial and final braking 
tests of the reference tyre within a test cycle;  
(c) The temperature -corrected average peak braking force coefficients 
(µpeak,corr , see paragraph  3.2.2. of this Annex) as calculated from the 
initial and from the final braking test of the reference tyre within a test 
cycle shall be not less than 0.65 and not greater than 0.90.  
If one or more of the above conditions is not met, the complete test cycl e shall 
be performed again.  
 For the candidate tyre(s) (T n): 
 The coefficient of variation of the peak braking force coefficient CV µ is 
calculated for each candidate tyre. If one coefficient of variation is greater than  
4 per cent,  the data shall be discar ded and the braking test repeated for this 
candidate tyre."  
Part (B), Heading , amend to read:  
"(B) – Classes  C2 and C3  tyres  
Paragraph 1.1.1. , amend to read:  
"1.1.1.  Standard Reference Test Tyre method  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
26 This method uses the SRTT16.  
Using the procedure described in paragraph  4.2. of part (A) of this Annex, 
perform in the same area where the average macro texture depth was measured 
one braking test of the reference tyre, consisting of at least six (6) valid test 
runs in the same direct ion. 
Evaluate the braking test as described in paragraphs  4.2.8.1. and 4.2.8.2. of 
part (A) of this Annex. If the coefficient of variation CV µ exceeds 4  per cent, 
dismiss the results and repeat the braking test.  
The arithmetic mean ( 𝜇peak̅̅̅̅̅̅) of the  measured  peak braking force coefficients  
shall be corrected for the effects of temperature as follows:  
𝜇peak,corr =𝜇peak̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
where  
ϑ is the wetted track surface temperature in degrees Celsius,  
𝑎= 0.002  ℃−1 and 𝜗0=20 ℃. 
The temperature corrected average peak braking force coefficient  (µpeak,corr ) 
shall be not less than 0.65 and not greater than 0.90 . 
The test shall be conducted using the lanes and length of the track to be used 
for the wet adhesion measurement.  
For the trailer method, testing is r un in such a way that braking occurs within 
10 metres  distance  of where the surface was characterized."  
Paragraph 1.4., amend to read:  
"1.4.  In order to cover the range of the tyre sizes fitting the commercial vehicles, the 
Standard Reference Test Tyres (S RTT) shall be used to measure the relative 
wet index as shown in the following table:  
For class C3 tyres  
Narrow family  
SNominal  < 285 mm  Wide family  
SNominal  > 285 mm  
SRTT19.5  SRTT22.5  
For class C2 tyres  
SRTT16C  
SNominal = Tyre nominal section width  
 " 
Paragraph 2. , amend to read:  
"2.  Test procedure  
The comparative wet adhesion level shall  be established using either:  
(a) A trailer or special purpose tyre evaluation vehicle; or  
(b) A standard production vehicle (M 2, M 3, N1, N2 or N 3, category) as 
defined in the Consolidated Resolution on the Construction of Vehicles 
(R.E.3.) ." 
Paragraph 2.1.1.4. , amend to read:  
"2.1.1.4.  In the case a track wetting system is incorporated:  
The system shall be able to deliver the water such that the tyre  and track surface 
in front of the tyre are wetted before the start of braking and throughout the 
duration of the test. The apparatus may be optionally equipped with a 
pavement -wetting system, less the storage tank, which, in the case of the trailer, 
is mo unted on the tow vehicle. The water being applied to the pavement ahead E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
27 of the test tyres shall be supplied by a nozzle suitably designed to ensure that 
the water layer encountered by the test tyre has a uniform cross section at the 
test speed with a minim um splash and overspray.  
The nozzle configuration and position shall ensure that the water jets shall be 
directed toward the test tyre and pointed toward the pavement at an angle of 15 
to 30°. The water shall strike the pavement 0.25 to 0.5 m ahead of the centre 
of tyre contact. The nozzle shall be located 100 mm above the pavement or the 
minimum height required to clear obstacles which the tester is expected to 
encounter, but in no case more than 200 mm above the pavement. The water 
layer shall be at least  25 mm wider than the test tyre tread and applied so the 
tyre is centrally located between the edges. The volume of water per unit of 
wetted width shall be directly proportional to the test speed. The quantity of 
water applied at 50 km/h shall be 14 l/s pe r metre  of the width of the wetted 
surface. The nominal values of rate of water application shall be maintained 
within 10 per cent."  
Paragraph 2.1.2.14. , amend to read:  
"2.1.2.14.  The wet grip index (G) shall be calculated as:  
Wet grip index (G) = μ peak,ave  (T)/μ peak, ave  (R) 
It represents the relative wet grip index for braking performance of the 
candidate tyre (T) compared to the reference tyre (R)."  
Paragraph 2.2.2.2. , amend to read:  
"2.2.2.2.  Vehicle equipment  
The rear ax le may be indifferently fitted with 2 or 4 tyres.  
For the reference tyre testing, both axles are fitted with reference tyres. (A total 
of 4 or 6 reference tyres depending on the choice above mentioned).  
For the candidate tyre testing, 3 fitting configura tions are possible:  
(a) "Configuration 1": candidate tyres on front and rear axles: it is the 
standard configuration that should be used every time it is possible.  
(b) "Configuration 2": candidate on front axle and reference tyre or control 
tyre on rear axle: allowed in such cases where fitting the candidate tyre 
on the rear position is not possible.  
(c) "Configuration 3": candidate on  rear axle and reference tyre or co ntrol 
tyre on front axle: permitted in such cases where fitting the candidate 
tyre on the front position is not possible."  
Paragraph 2.2.2.6.1. , amend to read:  
"2.2.2.6.1.  First, mount the set of reference tyres on the vehicle.  
The vehicle accelerates in t he starting zone up to 65 ± 2 km/h.  
Activation of the brakes on the track is made always at the same place with a 
tolerance of 5  metres  in longitudinal and 0.5  metres  in transverse ." 
Paragraph 2.2.2.7.4. , amend to read:  
"2.2.2.7.4.  Calculation of braking f orce coefficient, BFC  
BFC(R) and BFC(T) are calculated according to Table 6:  
Table 6  
Tested tyre  Braking force coefficient is  
Reference tyre  BFC(R) = Ra/g  
Candidate tyre  BFC(T) = Ta/g  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
28 g is the acceleration due to gravity (rounded to 9.81 m ⋅s−2). 
Ta (a = 1, 2, etc.) is the average of the AD values for a test of a candidate tyre."  
Paragraph 2.2.2.7.5. , amend to read:  
"2.2.2.7.5.  Calculation of the relative wet grip index of the tyre  
The wet grip index represents the relative performance of the candidat e tyre 
compared to the reference tyre. The way to obtain it depends on the test 
configuration as defined in paragraph 2.2.2.2. of this Annex. The wet grip 
index G of the tyre is calculated as reported into Table 7:  
Table 7  
Configuration C1:  
candidate tyres on both axles  𝐺=𝐵𝐹𝐶 (𝑇)
𝐵𝐹𝐶 (𝑅) 
Configuration C2:  
candidate tyres on front axle 
and reference tyres on rear axle  𝐺=𝐵𝐹𝐶 (𝑇)∙[𝑎+𝑏+ℎ∙𝐵𝐹𝐶 (𝑅)]−𝑎∙𝐵𝐹𝐶 (𝑅)
𝐵𝐹𝐶 (𝑅)∙[𝑏+ℎ∙𝐵𝐹𝐶 (𝑇)] 
Configuration C3:  
reference tyres on front axle 
and candidate tyres on rear axle  𝐺=𝐵𝐹𝐶 (𝑇)∙[−𝑎−𝑏+ℎ∙𝐵𝐹𝐶 (𝑅)]+𝑏∙𝐵𝐹𝐶 (𝑅)
𝐵𝐹𝐶 (𝑅)∙[−𝑎+ℎ∙𝐵𝐹𝐶 (𝑇)] 
Where (see also Figure 1):  
cog:  centre of gravity of the loaded vehicle  
m:  mass (in kilograms) of the loaded vehicle  
a:  horizontal distance between front axle and centre of gravity of the 
loaded vehicle (m)  
b:  horizontal distance between rear axle and centre of gravity of the loaded 
vehicle  
h:  vertical distance between ground level and centre of gravity of the 
loaded veh icle (m).  
N.B. When h is not precisely known, these worst case values shall 
apply: 1.2  m for configuration C2, and 1.5  m for configuration C3  
 loaded vehicle acceleration [m∙s−²]  
g: acceleration due to the gravity [m∙s−²]  
X1: longitudinal (X -direction) reaction of the front tyre on the road  
X2: longitudinal (X -direction) reaction of the rear tyre on the road  
Z1: normal (Z -direction) reaction of the front tyre on the road  
Z2: normal (Z -direction) reaction of the rear tyre on the road  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
29 Figure 1  
Nomenclature explanation related to grip index of the tyre  
 
  " 
Paragraph 2.2.2.8. , amend to read:  
"2.2.2.8.  Wet adhesion  comparison between a candidate tyre and a reference tyre using 
a control tyre  
When the candidate tyre size is significantly different from the reference tyre, 
a direct comparison on the same vehicle may be not possible. This approach 
uses an intermediate tyre, hereinafter called the control tyre."  
Annex 5 – Appendix, Example 1 , amend to read:  
"… 
No. 1 2 3 4 5 
Brand       
Pattern/ trade description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) inflation 
pressure(1) (kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       
Rim      
Load (kg)       
Pressure (kPa)       
µ
p
e
a
k 1      
2      
3      
4      
5      
m ∙ ɣ 
X1 
X2 
 m ∙ g 
h 
b 
 a 
Z1
g 
Z2
g 
cog E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
30 6      
7      
8      
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅       
Standard deviation, σµ      
CV µ ≤ 4 % (2)      
CVal (µpeak) ≤ 5 % (3)      
µpeak,corr (R)      
µpeak,adj (R)      
Wet grip index       
Wetted surface temp. (°C)       
Ambient temp. (°C)       
Remarks       
(1)  for classes C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall as 
required by paragraph 4.1. of this Regulation  
(2)  For classes  C2 and C3 tyres, the limit is 5 %.  
(3)  For classes C2 and C3 tyres, CVal (µpeak) is not defined nor applied."  
Annex 5 – Appendix, Example 2 , amend to read:  
"Example 2:  Test report of wet grip index using vehicle method  
Test report number:    Test date:      
         
Track:     Minimum:  Maximum:   Vehicle   
Texture depth (mm):    Wetted surface temp. (°C):     Brand:   
BFC ave,corr,1 :   Ambient temp (°C):     Model:   
BFC ave,corr,2 :       Type:   
CVal (BFC ave,corr ):       Year of registration:   
Water depth (mm):        Maximum axle load:  Front  Rear  
         
Initial speed (km/h):    Final speed (km/h):      
 
No. 1 2 3 4 5 
Brand       
Pattern /trade  description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) inflation 
pressure(1) (kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       
Rim      
Front axle pressure (kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle pressure (kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Front axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
 Braking 
distance  
(m) BFC i Braking 
distance 
(m) BFC i Braking  
distance 
(m) BFC i Braking 
distance 
(m) BFC i Braking 
distance 
(m) BFC i 
Measurement  1           E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
31  2           
 3           
 4           
 5           
 6           
 7           
 8           
 9           
 10           
𝐵𝐹𝐶𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅       
Standard deviation, σ BFC      
CV BFC ≤ 4 % (2)      
CVal (BFC ave) ≤ 5 % (3)      
BFC ave,corr (R)      
BFC adj(R)      
Wet grip index       
Wetted surface temp. (°C)       
Ambient temp. (°C)       
Remarks       
(1)  for classes  C2 and C3 tyres , corresponding to the indication of the inflation pressure marked on the sidewall as required 
by paragraph 4.1. of this Regulation.  
(2)  For classes  C2 and C3 tyres, the limit is 3 %.  
(3)  For classes  C2 and C3 tyres, CVal (BFC ave) is not defined nor applied."  
Annex 6 , 
Paragraph 2.1.1. , amend to read:  
"2.1.1.  Diameter  
 The test dynamometer shall have a cylindrical flywheel (drum) with a diameter 
of at least  1.7 m. 
 The F r and C r values shall be expressed relative to a drum diameter of 2.0  m. 
If drum diameter different than 2.0  m is used, a correlation adjustment shall be 
made fol lowing the method in paragraph  6.3. of this Annex."  
Paragraph 2.2. , amend to read:  
"2.2.  Measuring rim  
The tyre shall be mounted on a steel or light alloy measuring rim, as follows:  
(a) For class C1 tyres, the width of the rim shall be as defined in ISO  4000-
1:2015,  
(b) For classes C2 and C3 tyres, the width  of the rim shall be as defined in 
ISO 4209  1:2001.  
In cases where the width is not defined in the above -mentioned ISO Standards, 
the rim width as defined by one of the standards organizations as specified in 
Appendix 4 may be used."  
Paragraph 2.4.2. , amend to read:  
"2.4.2.  Alternative conditions  
 If the test ambient temperature is different from the reference ambient 
temperature, the rolling resistance measurement shall be correct ed to the 
reference ambient temperature in accordance with paragraph  6.2. of this 
Annex."  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
32 Table 1. , amend to read:  
  "Table 1  
  Test Speeds (in km/h)  
Tyre class  C1 C2 and C3  C3 
Load index  All LI ≤ 121  LI > 121  
Speed category 
symbol  All All J (100 km/h) and lower  K (110 km/h) 
and higher  
Test speed 
(km/h)  80 80 60 80 
" 
Table 2 , amend to read:  
  Table 2  
Test loads and inflation pressures  
Tyre class  C1 C2, C3  
 Standard 
load Reinforced or extra 
load  
Load - % of 
maximum load 
capacity as indicated 
by the load capacity 
index   
80  
80  
85 
(Refer  to single application)  
Inflation pressure  
kPa  
210  
250 Test inflation pressure corresponding 
to the indication of the inflation 
pressure marked on the sidewall as 
required by paragraph 4.1. of this 
Regulation.  
Note : The inflation pressure shall be capped with the accuracy specified in paragraph  4. of 
 Appendix  1 to this Annex.  
" 
Paragraph 3.5. , amend to read:  
"3.5.  Duration and speed.  
When the deceleration method is selected, the following requirements apply:  
(a) The deceleration j shall be determined in differential dω/dt or discrete 
Δω/Δt form, where ω is angular velocity, t – time;  
If the differential form dω/dt is used, then the recommendations of 
Appendix 5 to this annex are to be  applied;  
(b) For duration Δt, the time increments shall not exceed 0.5 s;  
(c) Any variation of the test drum  speed shall not exceed 1 km/h within one 
time increment."  
Paragraph 4.2. , amend to read:  
"4.2.  Thermal conditioning  
 The inflated tyre shall be placed in the thermal environment of the test location 
for a minimum of:  
(a) 3 hours for class C1 tyres;  
(b) 6 hours for classes C2 and C3 tyres."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
33 Table 3. , amend to read:  
  "Table 3  
Warm up durations  
Tyre cl ass C1 C2 and C3  
LI ≤ 121  C3 
LI > 121  
Nominal  rim diameter  All All < 22.5  ≥ 22.5  
Warm up duration  30 min.  50 min.  150 min.  180 min.  
" 
Paragraph 4.5.(j) , amend to read:  
"(j) Tyre size, manufacturer, type, identity number (if one exists), speed 
category  symbol, load index, DOT number (Department of 
Transportation)."  
Paragraph 4.6.1.(a)(ii) , amend to read:  
"(ii) Class C2 tyres: recommended value of 150 N; not to exceed 200 
N for machines designed for class C1 tyre measurement or 500 
N for machine designed for classes C2  and C3 tyres;"  
Paragraph 4.7. , amend to read:  
"4.7.  Allowance for machines exceeding σ m criterion  
 The steps described in paragraphs 4.3. to 4.5. above shall be carried out once 
only, if the measurement standard deviation determined in accordance with 
paragraph  6.5. below is:  
 (a) Not greater than 0.075 N/kN for classes C1 and C2 tyres;  
 (b) Not greater than 0.06 N/kN for class C3 tyres.  
 If the measurement standard deviation exceeds this criterion, the measurement 
process will be repeated n times as described in paragraph  6.5. below. The 
rolling resistance value reported shall be the average of the n measurements."  
Paragraph 5.1.2. , amend to read:  
"5.1.2.  Force method at tyre spindle  
 Calculate: F pl = F t (1 + rL/R) 
Where:  
Ft  is the tyre spindle force in newton (see paragraph  4.6.1. above),  
rL  is the distance from the tyre axis to the drum outer surface under 
steady state conditions, in  metres , 
R  is the test drum radius, in  metres ." 
Paragraph 5.1.3. , amend to read:  
"5.1.3.  Torque method at drum axis  
 Calculate:  Fpl = T t/R 
Where:  
Tt  is the input torque in newton metres , as determined in 
paragraph  4.6.1,  
R  is the test drum radius, in  metres ." 
Paragraph 5.1.4. , amend to read:  
"5.1.4.  Power method at drum axis E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
34  Calculate:  
nplUA V 6 , 3F=  
Where:  
V  is the electrical potential applied to the machine drive, in volts,  
A  is the electric current drawn by the machine drive, in amperes,  
Un  is the test drum speed, in  kilometres  per hour. " 
Paragraph 5.1.5. , amend to read:  
"5.1.5.  Deceleration method  
 Calculate the parasitic losses F pl, in newtons.  




 +



 =
00 T
rT
00 D D
plRI
t RIF
 
Where:  
ID  is the test drum inertia in rotation, in kilogram  metres  squared,  
R  is the test drum surface radius, in  metres , 
ΔD0  is the test drum angular speed increment, drum without tyre, in 
radians per second,  
t0  is the time increment chosen for the measurement of the parasitic 
losses without tyre, in seconds,  
IT  is the spindle, tyre and wheel inertia in rota tion, in kilogram 
metres  squared,  
Rr  is the tyre rolling radius, in metres , 
ΔT0  is the tyre angular speed increment, unloaded tyre, in radians per 
second.  
or  
T0
rT
D0D
pl jRIjRIF + =
 
Where:    
ID  is the test drum inertia in rotation, in kilogram  metres  squared,  
R  is the test drum surface radius, in  metres , 
jD0  is the deceleration of the test drum, without tyre, in radians per 
second squared,  
IT  is the spindle, tyre and wheel inertia in rotation, in kilogram  
metres  squared,  
Rr  is the tyre rolling radius, in metres , 
jT0  is the deceleration of unloaded tyre, in radians per second 
squared."  
Paragraph 5.2.2. , amend to read:  
"5.2.2.  Force method at tyre spindle  
 The rolling resistance Fr, in newtons, is calculated using the equation  
Fr = F t[1 + (rL/R)] − Fpl 
Where:  
Ft  is the tyre spindle force in newtons,  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
35 Fpl  represents the parasitic losses as calculated in paragraph  5.1.2. 
above,  
rL  is the distance from the tyre axis to the drum outer surface under 
steady -state conditions, in  metres , 
R  is the test drum radius, in  metres ." 
Paragraph 5.2.3. , amend to read:  
"5.2.3.  Torque method at drum axis  
 The rolling resistance F r, in newton s, is calculated with the equation  
 
Where:  
Tt  is the input torque, in newton  metres , 
Fpl  represents the parasitic losses as calculated in paragraph  5.1.3. 
above,  
R  is the test drum radius, in  metres ." 
Paragraph 5.2.4. , amend to read:  
"5.2.4.  Power method at drum axis  
 The rolling resistance Fr, in newtons, is calculated with the equation:  
 
Where:    
V = is the electrical potential applied to the machine drive, in volts,  
A = is the electric current drawn by the machine drive, in amperes,  
Un = is the test drum speed, in kilometres per hour,  
Fpl = represents the parasitic losses as calculated in paragraph  5.1.4. 
above."  
Paragraph 5.2.5. , amend to read:  
"5.2.5.  Deceleration method  
The rolling resistance Fr, in newtons, is calculated using the equation: 
pl
VV
2
rT
VV DFtω
RI R
tω
RIFr −



 +



=
 
Where:    
ID  is the test drum inertia in rotation, in kilogram  metres  squared,  
R  is the test drum surface radius, in  metres , 
Fpl  represents the parasitic losses as calculated in paragraph  5.1.5. 
above,  
tv  is the time increment chosen for measurement, in seconds,  
Δv  is the test drum angular speed increment, without tyre, in radians 
per second,  
IT  is the spindle, tyre and wheel inertia in ro tation, in kilogram 
metres  squared,  
Rr  is the tyre rolling radius, in  metres , 
t
r plTFFR=−
r pl
n3,6VAFFU=−E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
36 Fr  is the rolling resistance, in newtons.  
or 
pl V 2
rT
VDF j
RI RjRIFr −+ =
 
Where:    
ID  is the test drum inertia in rotation, in kilogram  metres  squared,  
R  is the test drum surface radius, in  metres , 
Fpl  represents the parasitic losses as calculated in paragraph  5.1.5. 
above,  
jV  is the deceleration of the test drum, in radians per second 
squared,  
IT  is the spindle, tyre and wheel inertia in rotation, in kilogram  
metres  squared,  
Rr  is the tyre rolling radius, in  metres , 
Fr  is the rolling resistance, in newtons."  
Paragraph 6.2. , amend to read:  
"6.2.  Temperature correction  
 If measurements at temperatures other than 25 C are unavoidable (only 
temperatures not less than 20 C or more than 30 C are acceptable), then a 
correction for temperature shall be made using the following equation, with:  
 Fr25 is the rolling resistance at 25 C, in newtons:  
 
Where:   
 is the rolling resistance, in newtons,  
 is the ambient temperature, in degrees Celsius,  
 is equal to:  
0.008  for class C1 tyres  
0.010  for classes C2 and C3 tyres with a load index equal or 
lower than 121  
0.006  for class C3 tyres with a load index greater than 121"  
Paragraph 6.3. , amend to read:  
"6.3.  Drum diameter correction  
 Test results obtained from different drum diameters shall be compared by using 
the following theoretical formula:  
 
 With:  
 
Where:    
R1  is the radius of drum 1, in  metres , 
R2  is the radius of drum 2, in  metres , 
( )   F F K tr r amb 25 1 25 = + −
Fr
tamb
K
F KFr r 02 01
) ) ( (
) (TT
r Rr R R RK++=
12 2 1E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
37 rT  is one -half of the nominal design tyre diameter, in  metres , 
Fr01  is the rolling resistance value measured on drum 1, in newtons,  
Fr02  is the rolling resistance value measured on drum 2, in 
newtons."  
Paragraph 6.5. , amend to read:  
"6.5.  The laboratory shall ensure that, based on a minimum of three measurements, 
the machine maintains the following values of σ m, as measured on a single tyre:  
 σm  ≤ 0.075 N/ kN for tyres of classes C1 and C2  
 σm  ≤ 0.06 N/kN for tyres of class C3  
 If the above requirement for σ m is not met, the following formula shall be 
applied to determine the minimum number of measurements n (rounded to the 
immediate superior integer value) that are required by the machine to qualify 
for conformance with this Regulation.  
n = (σ m/ x)² 
 Where:  
 x = 0.075 N/kN for tyres of classes C1 and C2  
 x = 0.06 N/kN for tyres of class C3  
 If a tyre needs to be measured s everal times, the tyre/wheel assembly shall be 
removed from the machine between the successive measurements.  
 If the removal/refitting operation duration is less than 10 minutes, the warm -
up durations indicated in paragraph  4.3. above may be reduced to:  
 (a) 10 minutes for tyres of class C1;  
 (b) 20 minutes for tyres of class C2;  
 (c) 30 minutes for tyres of class C3."  
Annex 6 - Appendix 1  
Paragraph 2.1. , amend to read:  
"2.1.  Width  
For passenger car tyre rims (class C1 tyres), the test rim width shall be th e 
same as the measuring rim determined in ISO  4000 -1: 2010, clause 6.2.2.  
For truck and bus tyres (classes C2  and C3), the rim width shall be the same as 
the measuring rim determined in ISO  4209 -1:2001, clause 5.1.3.  
In cases where the width is not defined in the above -mentioned ISO Standards, 
the rim width as defined by one of the standards organizations as spec ified in 
Appendix 4 to Annex 6 may be used."  
Paragraph 2.2. , amend to read:  
"2.2.  Run-out 
 In case vehicle rims are used, the run -out shall meet the following criteria:  
 (i) for class C1 tyres, class C2 tyres and for class C3 tyres with LI ≤ 121:  
 (a) Maxi mum radial run -out: 0.5 mm;  
 (b) Maximum lateral run -out: 0.5 mm;  
 (ii) for class C3 tyres with LI ≥ 122:  
 (a) Maximum radial run -out: 2.0 mm,  
 (b) Maximum lateral run -out: 2.0 mm."  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
38 Paragraph 4.  (a), amend to read:  
 "(a) Tyre loading:  
(i) For class C1 tyre s, class C2 tyres and for class C3 tyres with LI ≤ 
121: ±20 N or ±0.5 per cent, whichever is greater;  
(ii) For class C3 tyres with LI ≥ 122: ±45 N or ±0.5 per cent whichever 
is greater;"  
Paragraph 5. , amend to read:  
"5. Instrumentation accuracy  
 The instrumentation used for readout and recording of test data shall be 
accurate within the tolerances stated below:  
Parameter  class C1 tyres, class C2 tyres and 
class C3 tyres with LI ≤ 121 class C3 tyres with LI ≥ 122  
Tyre load  ±10 N or ±0.5  % (a) ±30 N or ±0.5  % (a) 
Inflation pressure  ±1 kPa ±1.5 kPa 
Spindle force  ±0.5 N or ±0.5  % (a) ±1.0 N or ±0.5  % (a) 
Torque input  ±0.5 Nm or ±0.5  % (a) ±1.0 Nm or ±0.5  % (a) 
Distance  ±1 mm ±1 mm 
Electrical power  ±10 W ±20 W 
Temperature  ±0.2 °C 
Surface speed  ±0.1 km/h  
Time  ±0.01  s - ±0.1 % - ±10 s(b)  
Angular velocity  ±0.1 % 
(a)  Whichever is greater.  
(b)  ±0.01 s  for the time increments specified in Annex 6, paragraph 3.5.( b) for the data acquisition in 
the deceleration method in ∆ω/∆t form  
±0.1 per cent for the time increments specified in Annex 6, paragraph 3.5.(a) for the data acquisition in 
the deceleration method  in dω/dt form  
± 10 sec for the other time durations specified in Annex 6."  
Paragraph 6. , amend to read:  
"6. Compensation for load/spindle force interaction and load misalignment for the 
force method only  
 Compensation of both load/spindle force interaction ("cross talk") and load 
misalignment may be achieved either by recording the spindle force for both 
forward and reverse tyre rotation or by dynamic machine calibration. If spindle 
force is recorded for forward and reverse directions (at each te st condition), 
compensation is achieved by subtracting the "reverse" value from the 
"forward" value and dividing the result by two. If dynamic machine calibration 
is intended, the compensation terms may be easily incorporated in the data 
reduction.  
 In cas es where reverse tyre rotation immediately follows the completion of the 
forward tyre rotation, a warm -up time for reverse tyre rotation shall be at 
least 10 minutes for class  C1 tyres and  30 minutes for all other tyre types."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
39 Annex 6 - Appendix 3  
Part 1,  
Item 6.1. , amend to read:  
"6.1.  Snow tyre for use in severe snow conditions (Yes/No)2 ................................ ............  " 
Footnote s (1) and (2) , amend to read:  
"(1) for classes C2 and C3 tyres, corresponding to the indication of the inflation pressure marked on the 
sidewall as req uired by paragraph 4.1. of this Regulation as indicated on the sidewall."  
(2) strike out what does not apply. " 
Annex 7  
Paragraphs 1. to 1.2. , delete.  
Paragraph 1.3. , renumber as paragraph 1. and amend to read:  
"1. The traction test shall be performed  according to ASTM standard:  
(a) F1805 -06 in case SRTT14 is used as reference tyre or  
(b) F1805 -20 in case SRTT16 is used as reference tyre ." 
Paragraph 1.4. , delete.  
Paragraph 2. , amend to read:  
"2. Spin traction method for classes  C1 and C2 tyres  (traction force test per 
paragraph 6.4. (b) of this Regulation)  
 The test procedure of ASTM standard F1805 -06 or F1805 -20, as applicable 
according to paragraph 1.3., shall be used to assess snow performance through 
the traction performance index (TPI) on medium pack snow (The snow 
compaction index measured with a CTI penetrometer1 shall be between 70  and 
80)."  
 "1 See appendix of ASTM standard F1805 -06 for details.  " 
Paragraph 3. , amend to read:  
"3. Braking on snow method for classes C1 and C2 tyr es" 
Paragraph 3.1.1. , amend to read:  
"3.1.1.  Test course  
The braking tests shall be done on a flat test surface of sufficient length and 
width, with a maximum 2 per cent gradient, covered with packed snow.  
The snow surface shall be composed of a hard packe d snow base at least 3  cm 
thick and a surface layer of medium packed and prepared snow about 2  cm 
thick.  
The air temperature, measured about one metre  above the ground, shall be 
between −15  °C and −2  °C; the snow temperature, measured at a depth of 
about one centimetre , shall be between −15  °C and −4  °C. 
It is recommended to avoid direct sunlight, large variations of sunlight or 
humidity, as well as wi nd. 
 The snow compaction index measured with a CTI penetrometer  shall be 
between 75 and 85."  
Paragraph 3.1.4.1. , amend to read:  
"3.1.4.1.  For class C1 tyres, the vehicle load shall be such that the resulting loads on the 
tyres are between 60  per cent and 9 0 per cent of the load corresponding to the 
tyre load index.  
 The cold inflation pressure shall be 240 kPa."  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
40 Paragraph 3.1.4.2. , amend to read:  
"3.1.4.2.  For class C2  tyres, the vehicle load shall be such that the resulting loads on the  
tyres are between  60 per cent and 100  per cent of the load corresponding to the 
tyre load index. …"  
Paragraph 3.1.6. , amend to read:  
"3.1.6.  In order to run this test, the Standard Reference Test Tyres (SRTT) as shown 
in the following table shall be used:  
Class C1 tyres Class C2 tyres  
SRTT14 or SRTT16  SRTT16C  
 " 
Paragraph 3.4.2. , amend to read:  
"3.4.2.  Statistical validations  
 The sets of repeats of measured or computed mfdd for each tyre should be 
examined for normality, drift, eventual outliers.  
 The consistency of the arithmetic means 𝑎̅ and corrected sample standard 
deviations 𝜎𝑎 of successive braking tests of SRTT should be examined.  
In addition and in order to take in account possible test evolution, the 
coefficient of validation CVal a(SRTT)  is calculated on the basis of the average 
values of any two consecutive groups of the minimum 6 runs of the Standard 
Reference Test Tyre according to  
𝐶𝑉𝑎𝑙 𝑎(SRTT )=100%  × |𝑎𝑅2̅̅̅̅̅− 𝑎𝑅1̅̅̅̅̅
𝑎𝑅1̅̅̅̅̅| 
The coefficient of validation CVal a(SRTT)  shall not differ by more than  5 per 
cent.  
 The coefficient of variation CV a , as defined in paragraph 3.4.1.1. of this 
Annex, of any braking test shall be less than 6  per cent.  
 If those conditions are not met, tests shall be performed again after re -
grooming the te st course."  
Paragraph 4. , amend to read:  
"4. Acceleration method for class C3 tyres"  
Paragraph 4.3.2. , amend to read:  
"4.3.2.  The following tolerances shall be respected:  
(a) For speed measurements:  ±1 per cent or 0.5 km/h whichever is greater.  
(b) For distance measurements:  ±1 x 10−1 m" 
Paragraph 4.4.1.3. , amend to read:  
"4.4.1.3.  The air temperature, measured about one  metre  above the ground, shall be 
between −15  °C and −2  °C; the snow temperature, measured at a depth of 
about one  centimetre , shall be between −15  °C and −4  °C. 
Air temperature shall not vary more than 10  °C during the test."  
Paragraph 4.7. , amend to read:  
"4.7.  Acceleration on snow test procedure for snow grip index of class C3"  
Paragraph 4.7.2.1.1. , amend to read:  
"4.7.2.1.1.  In the particular case where a standard commercial vehicle equipped with a 
traction control system is not available, a vehicle without Traction 
Control/ASR/TCS is permitted provided the vehicle is fitted  with a system to E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
41 display the percentage slip as stated in paragraph 4.3.4. of this Annex and a 
mandatory differential lock on the driven axle used in accordance with 
operating procedure 4.7.5.2.1. below.  If a differential lock is available it shall 
be used; if the differential lock, however, is  not available, the average slip ratio 
should be measured on the left and right driven wheel."  
Paragraph 4.7.5.2.1. , amend to read:  
"4.7.5.2.1.  In the particular case of paragraph 4.7.2.1.1. of this Annex where a standard 
commercial vehicle equipped with a  traction control system is not available, 
the driver shall manually maintain the average slip ratio between 10 and 40 per 
cent (controlled slip procedure in place of the full slip) within the prescribed 
range of speeds. If a differential lock is not avail able, the averaged slip ratio 
difference between the left and right driven wheel shall not be higher than 8 
per cent for each run. All the tyres and runs in the test session are performed 
with controlled slip procedure."  
Paragraph 4.7.5.5. , amend to read:  
"4.7.5.5.  In case of traction control system equipped vehicle, the average slip ratio shall 
be in the range from 10 per cent to 40 per cent (calculated as per paragraph 
4.3.4. of this Annex)."  
Paragraph 4.8.5. , amend to read:  
"4.8.5.  Calculation of the sli p ratio  
The slip ratio can be calculated as the average of slip ratio as mentioned in  
paragraph 4.3.4. of this Annex or by comparing the average distance referred 
to in paragraph 4.7.5.3. of this Annex of  the minimum 6 runs to the distance of 
a run done wi thout slip  (very low acceleration)  
100distance  slip  Nodistance  slip  No distance  Average% Ratio Slip 
 −=
 
No slip distance means the wheel distance calculated on a run done with a 
constant speed or a continuous low acceleration."  
Paragraph 4.9.2. , amend to read:  
"4.9.2.  Principle of the approach  
The principle lies upon the use of a control tyre and 2 different vehicles for the 
assessment of a candidate tyre in comparison with a reference tyre.  
One vehicle can fit the reference tyre and the control tyre, the other the control 
tyre and the candidate tyr e. All conditions are in conformity with paragraph 
4.7. above.  
The first assessment is a comparison between the control tyre and the reference 
tyre. The result ( snow grip index SG1) is  the relative efficiency of the control 
tyre compared to the reference t yre. 
The second assessment is a comparison between the candidate tyre and the 
control tyre. The result (snow grip index SG2) is the relative efficiency of the 
candidate tyre compared to the control tyre.  
The second assessment is done on the same track as t he first one. The air 
temperature must be in the range of ±5  °C of the temperature of the first 
assessment. The control tyre set is the same set as the set used for the first 
assessment.  
The snow grip index SG of the candidate tyre compared to the referenc e tyre 
is deduced by multiplying the relative efficiencies calculated above:  
SG=SG1 ∙SG2" E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
42 Annex 7 – Appendix 2 , 
Title, amend to read:  
  "Test reports and test data for classes C1 and C2 tyres " 
Part 2., item 2.1. , amend to read:  
"2.1.  Test track characteristics:  
 At start of tests  At end of tests  Specification  
Weather     
Ambient temperature    –15 °C to –2 °C 
Snow temperature    –15 °C to –4 °C 
CTI index    75 to 85  
Other     
" 
Part 2., item 5 , amend to read:  
"5. Test results: mean fully developed decelerations (m  ∙ s−2) / traction coefficient(3) 
Run number  Specification  SRTT (1st test)  Candidate 1  Candidate 2  SRTT (2nd test)  
1      
2      
3      
4      
5      
6      
      
      
      
Mean       
Standard deviation       
Coefficient of 
variation  CV a ≤ 6 %     
Coefficient of 
Validation  CVal a(SRTT) 
≤ 5 %     
SRTT weighted 
average       
Factor f      
Snow grip index   1.00    
(1)  for class C2 tyres, corresponding to the indication of the inflation pressure marked on the sidewall 
as required by paragraph 4.1. of this Regulation  
(2)  for class C2 tyres, refer to single load  
(3)  Strike out what does not apply."  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
43 Annex 7 – Appendix 3 ,  
Title, amend to read:  
  "Test reports and test data for class C3 tyres " 
Part 2., item 2.1. , amend to read:  
"2.1.  Test track characteristics:  
 At start of tests  At end of tests  Specification  
Weather     
Ambient temperature    –15 °C to –2 °C 
Snow temperature    –15 °C to –4 °C 
CTI index    80 to 90  
Other     
" 
Insert a new Annex 8,  to read:  
"Annex 8 
  Procedures for ice performance testing relative to ice grip 
tyre of class C1  
1. Specific definitions for ice performance test when different from existing ones  
1.1. "Non-consecutive braking test cycles " means test cycles of braking tests 
performed at least after minimum refreshing (or new preparation) of the ice 
surface, or on a different test lane, or in a different day.  
1.2. "Reference load " (Qref) means the theoretical load capacity of a tyre at the test 
inflation pressure. It is expressed in kilograms. It may exceed the maximum 
load-carrying capacity of the test tyre as indicated by its load index.  
1.3. "Load -on-tyre rate " (RLoT) means the actual  static tyre load on the test vehicle 
divided by the reference load.  
1.4. "Set of tyres " means a set of four tyres.  
2. Braking on ice method for class C1 tyres   
The ice performance is determined by a testing method in which the mean fully 
developed deceleration of a candidate tyre in an ABS braking test on a flat 
surface made of ice is compared with that of a reference tyre.  
For determination of the ice performance, braking tests of a candidate tyre shall 
be performed in three (3) non -conse cutive braking test cycles.  
The relative performance shall be indicated by an ice grip index ( GI). 
2.1. General conditions  
2.1.1.  Test course  
2.1.1.1.  The braking tests shall be done on a flat test surface of sufficient length and 
width covered with smoot h ice with a maximum of 2 per cent gradient.  
2.1.1.2.  The test course surface shall be flat, smooth, polished ice and watered around 
at least one hour before testing. The water used to make the ice shall be clean E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
44 and free of any solid inclusions. Before st arting the test, the braking line should 
be conditioned by conducting braking runs with a set of tyres not involved in 
the test program until the friction level stabilizes. The exact same test line shall 
be used for all braking test repetitions.  
2.1.1.3.  The surface grip level shall be controlled by measurements with the reference 
tyre. The average mean fully developed deceleration of the reference tyre shall 
be not less than 0.9 m/s² and not greater than 1.6 m/s² in each braking test.  
2.1.1.4.  The air tem perature, measured about one meter above the ground, shall be 
between −15  °C and +4  °C; the ice temperature, measured on the surface of 
the conditioned line, shall be between −15 °C and −5  °C. Both air and ice 
temperatures shall be reported for each tested  tyre. 
2.1.1.5.  Test cannot be conducted during snow fall or rain fall or any atmospheric 
precipitation. It is recommended to avoid direct sunlight, large variations of 
sunlight or humidity, as well as wind.  
2.1.1.6.  Indoor as well as outdoor facilities fo r ice tracks are accepted as far as the 
above requirements are met.  
2.1.2.  Vehicle  
2.1.2.1.  The test shall be conducted with a commercialized -model passenger car 
equipped with an ABS system in mechanical condition according to car 
manufacturer recommendati ons.  Permitted modifications are as follows: those 
allowing the number of tyres sizes that can be mounted on the vehicle to be 
increased, those permitting automatic activation of the braking device to be 
installed. Any other modification of the braking sy stem is prohibited. 
Increasing load on tyre by adding weight into the vehicle is permitted. Rim 
adapters or "spacers" for mounting wheels on the vehicle shall not exceed 60 
mm. 
2.1.3.  Tyres  
2.1.3.1.  Standard Reference Test Tyre  
 For the evaluation of the i ce performance of class C1 tyres, the Standard 
Reference Test Tyre SRTT16 shall be used. The reference tyre shall not be 
older than 30 months starting from the production week and shall be stored in 
accordance with ASTM F2493 – 20. "  
2.1.3.2.  Tyres prepara tion 
2.1.3.2.1.  Fit each test tyres on an approved rim pursuant to ISO 4000 -1 using 
conventional mounting methods. Subject to the foregoing, the rim width code 
shall not differ more than 0.5 from the measuring rim. If a commercialized rim 
is not available  for the test vehicle, it will be acceptable to use a rim whose rim 
width code differs by 1.0 from the measuring rim width code. Ensure proper 
bead seating by the use of a suitable lubricant. Excessive use of lubricant 
should be avoided to prevent slipping  of the tyre on the wheel rim.  
2.1.3.2.2.  The tyres should be "broken -in" prior to testing (at least 100 km on dry roads 
or with an equivalent method) to ensure stable performance and to remove 
spew, compound nodules or flash resulting from the moulding pr ocess. The 
tyre designed tread depth and designed tread block or rib integrity shall not 
change significantly with break -in, which means the pace and "severity" of the 
break -in run needs to be carefully controlled to avoid such changes.  
2.1.3.2. 3. It is acceptable to recondition a test tyre before the braking test to reach a 
stabilized performance level. 1 
2.1.3.2.4.  The tyre surface in contact with ice shall be cleaned before performing the test, 
removing snow and dirt.  
(1) It can be done, for example, by driving 5 km to 10 km on rough road surfaces or equivalent.  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
45 2.1.3.2.5.  Tyre and wheel assemblies shall be conditioned at the ambient temperature 
(outdoor or indoor depending on the test facility) at least two hours before they 
are fitted on th e vehicle for tests. Tyre pressures shall then be adjusted to the 
values specified for the test.  
2.1.3.2.6.  In case a vehicle cannot accommodate both the reference and candidate tyres, 
a third tyre ("control" tyre) may be used as an intermediate. First, te st the 
control tyre versus the reference on a suitable vehicle, then test the candidate 
tyre versus the control tyre on the selected vehicle.  
2.1.4. Tyre load and inflation pressure  
2.1.4.1.  Tyre load and inflation pressure shall be adjusted according to T able 1 
(depending on a direct comparison of candidate and reference tyre on the same 
vehicle, or an indirect comparison by using a control tyre and another vehicle).  
 Table 1  
 Tyre load and inflation pressure   
 Reference tyre  Control tyre  Candidate tyre  
Direct 
comparison  Inflation pressure : 
230 kPa ≤  ptest ≤ 260 kPa  
Load -on-tyre rate : 
65 % ≤ RLoT (R) ≤ 75 %   Inflation pressure : 
190 kPa ≤ ptest ≤ 270 kPa  
Load -on-tyre rate : 
RLoT(R) − 15% ≤ RLoT(T) ≤ 
RLoT(R) + 15%  
Indirect 
comparison  Vehicle 1:  
Inflation pressure : 
230 kPa ≤  ptest ≤ 260 kPa  
Load -on-tyre rate : 
65 % ≤ RLoT,1(R) ≤ 75 %  Vehicle 1:  
Inflation pressure : 
190 kPa ≤  ptest ≤ 270 kPa  
Load -on-tyre rate : 
RLoT,1(R) − 15% ≤ RLoT,1(C) ≤ 
RLoT,1(R) + 15%   
 Vehicle 2:  
Inflation pressure : 
190 kPa ≤  ptest ≤ 270 kPa  
Load -on-tyre rate : 
RLoT,1(C) − 15% ≤ RLoT,2(C) ≤ 
RLoT,1(C) + 15%  Vehicle 2:  
Inflation pressure : 
190 kPa ≤  ptest ≤ 270 kPa  
Load -on-tyre rate : 
60 % ≤ RLoT,2(T) ≤ 90 %  
Load -on-tyre rate RLoT is given by  
𝑅LoT=100% ∙𝑄tyre
𝑄ref 
where  
Qtyre is the actual static tyre load on the test vehicle, and  
Qref is the reference load at the test inflation pressure as determined below.  
2.1.4.2.  The reference load Qref at the test inflation pressure ptest is determined 
according to  
𝑄ref=𝑄LI∙(𝑝test
𝑝ref)0.8
 
where  
QLI  is the maximum tyre load -carrying capacity according to its load index,  
and E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
46 pref  is the reference inflation pressure as defined in Table 2.  
Table 2  
Reference inflation pressures  
Tyre pref  (kPa)  
Reference tyre  250 
Standard tyre  250 
Reinforced tyre (or "extra load " tyre)  290 
2.1.5.  Instrumentation  
2.1.5.1.  The vehicle shall be fitted with calibrated sensors suitable for measurements 
in cold and icy conditions. There shall be a data acquisition system to store 
measurements.  
2.1.5.2.  The accuracy of measurement sensors and systems shall be such that would 
allow a relative uncertai nty(2) of less than or equal to 1 per cent on the measured 
or computed mean fully developed deceleration. 3 
2.2. Testing order and braking test cycles  
2.2.1.  For each braking test of a test tyre, at least nine (9) valid test runs shall be 
performed.  
2.2.2.  Within one braking test cycle, up to two (2) candidate tyres may be tested. 
Several braking test cycles may be combined and the final braking test of the 
reference tyre of one braking test cycle may serve as the initial braking test of 
the subseque nt braking test cycle.  
(2) Suitable methods for determining the relative measurement uncertainty can be found, for example, 
in ISO/IEC Guide 98 -3, Uncertainty of measurement – Part 3: Guide to the expression of uncertainty 
in measurement (GUM:1995).    
(3) For example, in case the mean fully developed deceleration is computed according to paragraph 
2.4.1.1. of this Annex, the accuracy of the measurements sensors or systems for the measurements of 
the distance ( s) and of the speeds ( vi and vf) should be such that the composition of their relative 
uncertainties, based on 2. 4.1.1. of this Annex would allow to determine the mean fully developed 
deceleration with a relative uncertainty of less than or equal to 1 per cent.  
EXAMPLE 1  
For a braking test cycle with two candidate tyres, the order of testing is  
Ri – T1 – T2 – Rf 
where  
Ri/Rf   is the initial/final braking test of the reference tyre and  
T1, T2  are the braking tests of the two candidate tyres to be evaluated.  
 
EXAMPLE 2  
The run order for a series of braking test cycles with a total of four (4) candidate 
tyre sets (T 1 to T 4) would be the following:  
Ri – T1 – T2 – Rf/Ri – T3 – T4 – Rf, 
where the  final braking test of the reference tyre set (R f) of the first braking test 
cycle serves as initial braking test (R i) of the second braking test cycle.  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
47 For any candidate tyre at least three (3) non -consecutive braking test cycles 
shall be performed.  
2.3. Test procedure  
2.3.1.  The vehicle shall be fitted on all four positions with the same tyres.  
2.3.2.  Drive the vehicle in a straight line at a speed about 5 km/h higher than the 
upper speed of the evaluation interval.  
2.3.3.  When the measuring zone has  been reached, set the vehicle gear into neutral, 
press the brake pedal sharply down with a force sufficient to cause operation 
of the ABS on all wheels of the vehicle and to result in a stable deceleration of 
the vehicle and hold it down until the speed i s 0 km/h.  
2.3.4.  The mean fully developed deceleration dm shall be determined either between 
15 km/h and 5 km/h or between 20 km/h and 5 km/h. It shall be computed from 
measurements of either time (expressed in s), distance (expressed in m), or 
deceleratio n (expressed in m  ∙ s−2). For each test run in the braking tests (3 or 
4) of a braking test cycle and for all test tyres, the same evaluation speed 
interval shall be used.  
2.4. Data evaluation and presentation of results  
2.4.1. Data evaluation  
2.4.1.1. For a distance measurement, the mean fully developed deceleration dm in a test 
run is computed as:  
𝑑m=𝑣i2−𝑣f2
2𝑠 
 where  
vi is the initial speed expressed in m  ∙ s−1 
vf is the final speed expressed in m  ∙ s−1, and  
s is the distance, expressed in  metres, covered between the initial speed 
and the final speed.  
2.4.1.2. The highest and the lowest values (in total two (2) runs) of the at least nine 
valid test runs shall be disregarded in the evaluation of each braking test.  
2.4.1.3.  For each braking test in a braking test cycle, the arithmetic mean dm,ave and the 
standard deviation σd of the mean fully developed deceleration and the 
coefficient of variation CV d shall be computed and reported:  
𝜎𝑑=√1
𝑁−1∙∑ (𝑑m,𝑗−𝑑m,ave)2𝑁
𝑗=1   
and 
𝐶𝑉𝑑=100% ∙𝜎𝑑
𝑑m,ave 
2.4.2.  Calculation of the braking test ice grip index  
2.4.2.1.  For the calculation of the ice grip index GI,k(Tn) for an individual braking test, 
the mean fully developed deceleration of the reference tyre is adjusted 
according to t he positioning of each candidate tyre (T n) within a braking test 
cycle.  
2.4.2.2.  This adjusted mean fully developed deceleration dm,adj(R) of the reference tyre 
is calculated in accordance with Table 3, where dm,ave(Ri) and dm,ave(Rf) are the 
arithmetic me ans of the mean fully developed decelerations in the initial and 
in the final braking test of the reference tyre within a braking test cycle.  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
48 Table 3  
 Calculation of the adjusted mean fully developed deceleration dm,adj(R) of the reference 
tyre 
If the number and the sequence of 
candidate tyres within one braking test 
cycle is  and the candidate tyre to 
be qualified is  the corresponding adjusted mean fully developed deceleration 
dm,adj(R) of the reference tyre is calculated as follows  
1      R1 – T1 – R2 T1 𝑑m,adj (R)=12⁄∙[𝑑m,ave (Ri)+𝑑m,ave (Rf)] 
2      R1 –T1 – T2 – R2 T1 𝑑m,adj (R)=23⁄∙𝑑m,ave (Ri)+13⁄∙𝑑m,ave (Rf) 
T2 𝑑m,adj (R)=13⁄∙𝑑m,ave (Ri)+23⁄∙𝑑m,ave (Rf) 
2.4.2.2.  For an individual braking test, the ice grip index GI,k(Tn) of the candidate tyre 
Tn (n = 1, 2)  relative to the reference tyre is calculated as : 
𝐺I,𝑘(T𝑛)=𝑑m,ave(T𝑛)
𝑑m,adj(R) 
2.4.3.  Ice grip index  
 The ice grip index GI(Tn) of a candidate tyre shall be computed as the 
arithmetic mean of the ice grip indices GI,k(Tn) for the individual braking tests 
in the three non -consecutive braking test cycles as :  
𝐺𝐼(T𝑛)=1
3∙[𝐺𝐼,1(T𝑛)+𝐺𝐼,2(T𝑛)+𝐺𝐼,3(T𝑛)] 
An example of a full test report is given in appendix 2.  
2.4.4.  Statistical validation  
2.4.4.1.  The sets of mean fully developed decelerations dm within each braking test 
shall be examined for normality, drift, eventual outliers.  
2.4.4.2.  If the coefficient of variation CV d of a br aking test of a candidate tyre exceeds 
6 per cent, this braking test shall be discarded.  
2.4.4.3.  In the case that  
a) the coefficient of variation CV d of the initial or the final braking test of a 
reference tyre within a braking test cycle exceeds 6 per ce nt, or  
b) the arithmetic means of the mean fully developed decelerations of the 
initial and the final braking test of the reference tyre within a braking test 
cycle exceeds 5 per cent of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝑑m)=2・|𝑑m,ave (Ri)−𝑑m,ave (Rf)
𝑑m,ave (Ri)+𝑑m,ave (Rf)|・100% ≤5 %, or 
c) the mean fully developed deceleration of the reference tyre is less than 
0.9 m ∙ s−2 or greater than 1.6 m ∙ s−2 in the initial or the final braking test 
within a braking test cycle  
the complete braking test cycle shall be  discarded.  
2.4.4.4.  For each candidate tyre T n, the coefficient of variation CV G of the ice grip 
indices GI,k(Tn) for the individual braking tests in the three (3) non -consecutive 
braking test cycles shall be calculated as:  
𝐶𝑉𝐺=100 %・𝜎𝐺
𝐺I(T𝑛) 
where  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
49 𝜎𝐺=√1
2・∑[𝐺𝐼,𝑘(T𝑛)−𝐺𝐼(T𝑛)]23
𝑘=1 
and 
GI(Tn) is the ice grip index of candidate tyre T n. 
2.4.4.4.  If the coefficient of variation CV G exceeds 6%, for this candidate tyre T n 
additional braking tests shall be performed in non -consecutive braking cycles, 
until the coefficient of variation CV G calculated from any three braking tests 
of this candidate tyre meets the requirement.  
2.4.4.5.  The SRTT shall be discarded if it exhibits  irregular wear or damage or when 
the performance appears to have been deteriorated.  
2.4.5.  Ice performance comparison between a candidate tyre and a reference tyre 
using a control tyre  
2.4.5.1.  General  
2.4.5.1.1.  In case the candidate tyre cannot be fitte d on the same vehicle as the reference 
tyre, for example, due to tyre size, inability to achieve required load -on-tyre 
rate and required test inflation pressure, comparison shall be made using 
intermediate tyres, herein referred to as "control tyres", and two different 
vehicles.  
2.4.5.1.2.  The control tyre shall pass the ice grip index threshold defined in paragraph 
6.4.2. of this Regulation.  
2.4.5.1.3.  One vehicle shall be capable of being fitted with the reference tyre and the 
control tyre, and the other vehicle shall be capable of being fitted with the 
control tyre and the candidate tyre.  
2.4.5.2.  Ice grip index calculation in case of a control tyre  
2.4.5.2.1.  In a first series of three non -consecutive braking test cycles, using the 
procedure described in  paragraph 2.1.3.2. to 2.4.4.5. of this Annex in which 
the control tyre shall be treated as a candidate tyre, the ice grip index GI,1(C) 
of the control tyre relative to the reference tyre shall be established. In a second 
series of three non -consecutive br aking test cycles, in which the control tyre 
serves as reference tyre, the ice grip index GI,2(T) of the candidate tyre relative 
to the control tyre shall be established.  
2.4.5.2.2.  The ice grip index GI(T) of the candidate tyre relative to the reference tyre shall 
be calculated as the product of the two ice grip indices:  
𝐺𝐼(T)=𝐺𝐼,1(C)∙𝐺𝐼,2(T)  
2.4.5.3.  Boundary conditions  
2.4.5.3.1.  The same set of control tyres shall be used for comparison with the SRTT and 
with the candidate tyre and shall be fitted in the same wheel positions.  
2.4.5.3.2.  Control tyres that have been used for testing shall subsequently be stored under 
the same conditions as required for the SRTT.  
2.4.5.3.3.  The SRTT and control tyres shall be discarded if there is irregular wear or 
damage or when the performance appears to have been deteriorated.  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
50 Annex 8 - Appendix 1  
  Pictogram definition of "Ice Grip Symbol"  
  
Minimum 15 mm base and 13 mm height.  
Above drawing not to scale.  
Annex 8 - Appendix 2  
 Test reports and test data for C1 tyres  
Part 1 - Report  
1. Type Approval Authority or Technical Service:  ................................ ...............   
2. Name and address of manufacturer:  ................................ ................................ .  
3. Test report No.:  ................................ ................................ ................................ .  
4. Brand name and trade description :  ................................ ................................ ...  
5. Tyre class:  ................................ ................................ ................................ .........   
6. Category of use:  ................................ ................................ ................................   
7. Ice grip index relative to SRTT  
7.1. Test procedure and SRTT used  ................................ ................................ .........   
8. Comments (if any):  ................................ ................................ ...........................   
9. Date:  ................................ ................................ ................................ .................   
10. Signature:  ................................ ................................ ................................ ..........   
Part 2 - Test data : 1st braking test cycle  
1. Date of test:  ................................ ................................ ................................ .......  
2. Location of test track:  ................................ ................................ .......................   
2.1. Test track characteristics:  
 At start of test  At end of test  Specification  
Weather     
Ambient temperature    −15 °C to +4 °C  
Ice temperature    −15 °C to −5 °C  
Other     
3. Test vehicle (make, model and type, year):  ................................ ......................   
4. Test tyre details and data  ................................ ................................ ..................   
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
51  SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
Brand name      
Trade description/ 
commercial name      
Tyre size designation      
Service description      
Test rim width code      
Tyre load FL/FR/RL/RR 
(kg)     
Load -on-tyre rate 
(FL/FR/RL/RR)   ( %)     
Tyre pressure (kPa)      
5. Test results: mean fully developed decelerations (m  ∙ s−2) 
Run number  SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
1     
2     
3     
4     
5     
6     
7     
8     
9     
     
dm,ave     
σd     
CV d (  6 %)      
𝐶𝑉𝑎𝑙 (𝑑m) ( 5%)     
dm,adj(R)     
Ice grip index  1.00    
Part 2 - Test data: 2nd brak ing test cycle  
1. Date of test:  ................................ ................................ ................................ .......  
2. Location of test track:  ................................ ................................ .......................   
2.1. Test track characteristics:  
 At start of test  At end of test  Specification  
Weather     
Ambient temperature    −15 °C to +4 °C  
Ice temperature    −15 °C to −5 °C  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 6 
52  At start of test  At end of test  Specification  
Other     
3. Test vehicle (make, model and type, year):  ................................ .......................   
4. Test tyre details and data  ................................ ................................ ...................   
 SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
Brand name      
Trade description/ 
commercial name      
Tyre size designation      
Service description      
Test rim width code      
Tyre load FL/FR/RL/RR 
(kg)     
Load -on-tyre rate 
(FL/FR/RL/RR)   ( %)     
Tyre pressure (kPa)      
5. Test results: mean fully developed decelerations (m  ∙ s−2) 
Run number  SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
1     
2     
3     
4     
5     
6     
7     
8     
9     
     
dm,ave     
σd     
CV d ( 6 %)      
𝐶𝑉𝑎𝑙 (𝑑m) ( 5%)     
dm,adj(R)     
Ice grip index  1.00    
Part 2 - Test data: 3rd brak ing test cycle  
1. Date of test:  ................................ ................................ ................................ .......  
2. Location of test track:  ................................ ................................ .......................   
2.1. Test track characteristics:  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 6 
53  At start of test  At end of test  Specification  
Weather     
Ambient temperature    −15 °C to +4 °C  
Ice temperature    −15 °C to −5 °C  
Other     
3. Test vehicle (make, model and type, year):  ................................ .......................   
4. Test tyre details and data  ................................ ................................ ...................   
 SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
Brand name      
Trade description/ 
commercial name      
Tyre size designation      
Service description      
Test rim width code      
Tyre load FL/FR/RL/RR 
(kg)     
Load -on-tyre rate 
(FL/FR/RL/RR)   ( %)     
Tyre pressure (kPa)      
5. Test results: mean fully developed decelerations (m  ∙ s−2) 
Run number  SRTT (Initial 
braking test)   Candidate 1  Candidate 2  SRTT (final 
braking test)  
1     
2     
3     
4     
5     
6     
7     
8     
9     
     
dm,ave     
σd     
CV d ( 6 %)      
𝐶𝑉𝑎𝑙 (𝑑m) ( 5%)     
dm,adj(R)     
Ice grip index  1.00    
" 
     
  Agreement  
  Concerning the  Adoption of Harmonized Technical United Nations 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
Fitted and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these 
United Nat ions Regulations * 
(Revision 3, including the amendments which entered into force on 14 September 2017)  
_________  
  Addendum 116 – UN Regulation No. 117 
  Revision 4 - Amendment 7 
03 series of amendments  – Date of entry into force: 4 January 2023 . 
  Uniform  provisions concerning the approval of tyres with regard to 
rolling sound emissions and /or to adhesion on wet surfaces and/or to 
rolling resistance  
This document is meant purely as documentation tool. T he authentic and legal binding text is:  
ECE/TRANS/WP.29/ 2022 /83. 
_________  
UNITED NATIONS   
  
 * Former titles of the Agreement:  
  Agreement concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of 
Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);  
  Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, 
Equipment and Parts which can be Fitt ed and/or be Used on Wheeled Vehicles and the Conditions for 
Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 
5 October 1995 (Revision 2).   E/ECE/324/Rev. 2/Add. 116/Rev.4/Amend. 7−E/ECE/TRANS/505/Rev. 2/Add. 116/Rev. 4/Amend. 7 
   
 
20 February 2023  
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
2 Table of c ontents , Annexes,  at the end  add a reference to a new Annex 9 to read:   
"9 Test procedure for measuring the adhesion on wet surfaces of tyres in worn state  ...............................   ...........   
Appendix 1   Worn tyre preparation report example  ................................ ................................ ....  ...........   
Appendix 2   Test reports examples of wet grip index for tyres in worn state  .............................   ........   " 
Paragraph 1.1., amend to read :  
"1.1.  This Regulation applies to new pneumatic tyres * of classes C1, C2 and C3 in 
new state with regard to their sound emissions, rolling resistance and to 
adhesion performance on wet surfaces (wet adhesion) and for class C1 tyres in 
worn state with regard  to adhesion performance on wet surfaces (wet 
adhesion). It does not, however, apply to:  
 
*  For the purpose of this Regulation "tyres" means "pneumatic tyres"  
Paragraph 1.2., amend to read :  
"1.2.  Contracting Parties shall issue or accept approvals to ro lling sound and/or 
adhesion of tyres in new state on wet surfaces and/or adhesion of tyres in worn 
state on wet surfaces and/or rolling resistance."  
Paragraph 2.7. , amend to read:  
"2.7.  "Representative tyre size " means the tyre size which is submitted to the test 
described in Annex 3 to this Regulation with regard to rolling sound emissions, 
or Annex 5 for adhesion on wet surfaces or Annex 6 for rolling resistance to 
assess the conformity for the type approval of the type of tyre, or Annex 7 for 
measuring snow performance, or Annex 8 for measuring ice performance, or 
Annex 9 for adhesion on wet surfaces of class C1 tyres in worn state."  
Paragraph 2.13.1. , amend to read:  
"2.13.1.  "Snow tyre for use in severe snow conditions " means a snow tyre whose tread 
pattern, tread compound or structure is specifically designed to be used in 
severe snow conditions and that fulfils the requirements of paragraphs 6.5. and 
6.5.1. of this Regulation."  
Insert new paragraphs 2.19.17. and 2.19.18. , to read:  
"2.19.17.  "Tyre in worn state " or " worn tyre " means the tyre in a state as defined in 
Annex 9 to this Regulation.  
2.19.18.  "Tyre in n ew state " means the tyre in a state as defined in Annex 9 to this 
Regulation."  
Paragraph 3.1.1. , amend to read :  
"3.1.1.  The performance characteristics to be assessed for the type of tyre; "rolling 
sound emissions level" and/or "adhesion performance level on wet surfaces of 
a tyre in new state" and/or "adhesion performance level on wet surfaces of a 
tyre in worn state” and/or " rolling resistance level" ; "snow performance level" 
in case of "snow tyre for use in severe snow conditions" and additionally "ice 
performance level" in case of ice grip tyre ;" 
Paragraph 4.3.1., amend to read :  
"4.3.1.  In case the approval of a tyre pursuant to this Regulation has been granted by 
the same Type Approval Authority than that granting the approval pursuant to 
UN Regulations Nos.  30 or 54, the approval mark pursuant to UN Regulations 
Nos. 30 or 54 can be comb ined with an indication of the applicable series of 
amendments to which the tyre was approved pursuant to UN Regulation 
No. 117 on the form of 2 digits (example "03" indicating that the UN  
Regulation No. 117 approval was granted following the 03 series of  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
3 amendments) and the suffixes according to paragraph 5.2.2. using the addition 
sign "+", as described in Annex  2, Appendix  3 of this Regulation, for example 
"0236378 + 03S2WR2B"."  
Paragraph 5.2.2., amend to read :  
"5.2.2.  The communication form mentioned in  paragraph 5.3. below shall identify 
specific performance parameters of UN Regulation No. 117 by the following 
suffixes:  
S To identify additional conformity to the requirements on tyre rolling 
sound emissions;  
W To identify additional conformity to the req uirements on adhesion on 
wet surfaces of tyres in new state;  
R To identify additional conformity to the requirements on tyre rolling 
resistance;  
B  To identify additional conformity to the requirements on adhesion on 
wet surfaces of tyres in worn state.  
S and R will be followed by the suffix "2" for compliance to stage 2. " 
Paragraph 5.3.1.2., amend to read :  
"5.3.1.2.  The suffix(es) mentioned in paragraph 5.2.2. above shall be preceded by the 
two digits identifying the series of amendments of the prescription on tyre 
performances for UN Regulation No. 117, e.g. 03S2 to identify the third series 
of amendments on tyre roa d rolling sound emissions at stage  2 or 03S2WR2 to 
identify the third series of amendments on tyre road rolling sound emissions at 
stage 2, adhesion on wet surfaces of a tyre in new state and rolling resistance 
at stage  2." 
Paragraph 5.4.3., amend to read :  
"5.4.3.  The suffix(es), and the identification to the relevant series of amendments, if 
any, as specified in the communication form.  
 One of the suffixes listed below or any combination of them can be used.  
S2 Rolling sound emission level at stage 2  
W Wet adhesion level of tyres in new state  
R2 Rolling resistance level at stage 2  
B Wet adhesion level of tyres in worn state  
 These suffixes shall be placed to the right or below the approval number, if 
part of the original approval.  
 If the approval is extended subsequent to UN Regulations Nos.  30 or 54 
approvals, the addition sign "+" and the series of amendment to UN Regulation 
No. 117 shall be placed in front of the suffix or any combination of suffixes to 
denote an extension to the  approval.  
 If the approval is extended subsequent to the original approval under UN 
Regulation No.  117, the addition sign "+" shall be placed between the suffix 
or any combination of suffixes of the original approval and the suffix or any 
combination of s uffixes added to denote an extension to the approval. " 
Paragraph 6.1.1., amend to read :  
"6.1.1.  For class C1 tyres, the rolling sound emission value shall not exceed the values 
given below. These values refer to the nominal section width as defined in UN 
Regulation No.  30: E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
4 Stage 2  
Nominal section width  Limit dB(A)  
185 and lower  70 
Over 185 up to 245  71 
Over 245 up to 275  72 
Over 275  74 
The above limits shall be increased by 1 dB(A) for "snow tyre for use in severe 
snow conditions", extra load tyres or reinforced tyres, or any combination of these 
classifications.  
 " 
Paragraph 6.1.2., amend to read :  
"6.1.2.  For class C2 tyres, the rolling sound emission value with reference to its 
category of use (see paragraph  2.1., subparagraph (d) above)  shall not exceed 
the values given below:  
Stage 2  
Category of use   Limit dB(A)  
Other  Traction tyres  
Normal tyre   72 73 
Snow tyre   72 73 
Snow tyre for use in severe 
snow conditions  73 75 
Special use tyre   74 75 
 " 
Paragraph 6.1.3., amend to read :  
"6.1.3.  For class C3 tyres, the rolling sound emission value with reference to its 
category of use (see paragraph  2.1., subparagraph (d) above) shall not exceed 
the values given below:  
Stage 2  
Category of use   Limit dB(A)  
Other  Traction tyres  
Normal tyre   73 75 
Snow tyre   73 75 
Snow tyre for use in severe 
snow conditions  74 76 
Special use tyre   75 77 
 " 
Paragraph 6.2., amend to read : 
"6.2. The wet adhesion of tyres in new state will be based on a procedure that 
compares either peak brake force coefficient ("pbfc") or mean fully developed 
deceleration ("mfdd") against values achieved by a Standard Reference Test 
Tyre (SRTT). The relative performance shall be indicated by a wet grip 
index  (G)." E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
5 Parag raph 6.3., amend to read :  
"6.3. Rolling resistance coefficient limits, as measured by the method described in 
Annex  6 to this Regulation.  
 The maximum values for stage 2 for the rolling resistance coefficient shall not 
exceed the following (value in N/ kN is equivalent to value in kg/tonne):  
Tyre class  Max value (N/kN)  
C1 10.5 
C2 9.0 
C3 6.5 
For "snow tyre for use in severe snow conditions”, the limits shall be 
increased by 1 N/kN.  
 " 
Insert a new paragraph 6.4. , to read:  
"6.4. The wet adhesion of tyres in worn state shall be based on a procedure defined 
in Annex 9 to this Regulation.  
6.4.1.  For class C1 tyres, tested in accordance with either procedure given in Annex 
9 to this Regulation, the tyre shall meet the following requirements:  
Category of use   Wet grip index 
(GB) 
Normal tyre  ≥ 0.88  
Snow tyre  ≥ 0.80  
"Snow tyre for use in severe snow 
conditions" and with a speed 
category symbol ("R" and above, 
including "H") indicating a 
maximum permissible speed 
greater than 160 km/h   ≥ 0.80  
Ice grip tyre  ≥ 0.70  
"Snow tyre for use in severe snow 
conditions" and with a speed 
category symbol ("Q" or below 
excluding  "H") indicating a 
maximum permissible speed not 
greater than  160 km/h   ≥ 0.70  
Ice grip tyre  ≥ 0.70  
Special use tyre Not defined  
 For normal tyres with speed category symbol indicating a maximum permissible speed equal 
to or greater than 300 km/h and aspect ratio equal to or lower than 40, the limit shall be 
decreased by 0.08. " 
Paragraph 6.4. (former) and its subparagraphs, renumber  as 6.5. and its respective 
subparagraphs.    
Paragraph 6.5., (former), renumber as 6.6. and  amend to read :  
"6.6. In order to  be classified as a "traction tyre", a tyre is required to meet the 
condition s of paragraph  6.6.1. below."  
Paragraphs 6.5.1. (former), 6.6. (former) and 6.7., renumber as 6.6.1., 6.7. and 6.8., 
respectively.  
Insert a new paragraph 8.3.3. , to read:  
"8.3.3.  In the case of verification tests with regard to approvals in accordance with 
paragraph 6.4. of this Regulation, these shall be carried out using the same 
testing method (see Annex 9 to this Regulation) as that adopted for the original 
approval. " E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
6 Paragraph 12., amend to read :  
"12.  Transitional provisions  
12.1.  As from the official date of entry into force of the 03 series of amendments, no 
Contracting Party applying this Regulation shall refuse to grant or refuse to 
accept type approvals under this Regulation as amended by the 03 series of 
amendments.   
12.2.  Contracting Parties applying this Regulation shall continue to accept type 
approvals of and to grant extensions of approvals to, the classes C2 and C3 
tyres, which are not affected by the changes of the technical requirements 
concerning the adhesion on wet surfaces of class C1 tyres in worn state 
introduced by the 03 series of amendments, to the 02 series of amendments to 
this Regulation.  
12.3.  As from  7 July 2024, Contracting Parties applying this Regulation shall not be 
obliged to accept type approvals of class C1 tyres to the 02 series of 
amendments, first issued after 7 July 2024.  
12.4.  Until 7 July 2026, Contracting Parties applying this Regulation shall accept 
type approvals of class C1 tyres to the 02 series of amendments, first issued 
before 7 July 20 24. 
12.5.  As from  7 July 2026, Contracting Parties applying this Regulation shall not be 
obliged to accept type approvals of class C1 tyres issued to the 02 series of 
amendments to this Regulation.  
12.6.  Contracting Parties applying this Regulation may gra nt type approvals 
according to any preceding series of amendments to this Regulation.  
12.6.1.  Contracting Parties applying this Regulation shall continue to grant extensions 
of existing approvals to any preceding series of amendments to this Regulation.  
12.7. Until 1 September 2024, Contracting Parties applying this Regulation may 
continue to grant type approvals according to the 0203 series of amendments 
to this Regulation, based on snow performance test described in Annex 7 to 
this Regulation using SRTT14  as reference tyre. (a) 
12.8.  Until 1 September 2024, Contracting Parties applying this Regulation may 
continue to grant type approvals according to the 03 series of amendments to 
this Regulation, based on the test procedures for measuring the wet adhesion  
of tyres in new state as described in Annex 5 of this Regulation, without taking 
into account the provisions introduced after Supplement 12 to the 02 series of 
amendments.  
 (a) SRTT14 will be available from the supplier until end of October 2021. " 
Annex 1  
Paragraph 8., amend to read :  
"8. Performance(s) approved: rolling sound emission level at stage 2, wet adhesion level 
of tyres in new state, rolling resistance level at stage 2, wet adhesion level of tyres in 
worn state " 
Paragraph 8.2., amend to read :  
"8.2. Wet adhesion level of tyres in new state of representative size, see paragraph 2.7. of 
this Regulation, as per the test report examples shown in the appendix to Annex  5: 
……………………… (G) using the vehicle or trailer method2" 
Insert a new paragraph 8.3. , to read:  
"8.3. Wet adhesion level of tyres in worn state of representative size, see paragraph 2.7. of 
this Regulation, as per item  Y. of the test report in the appendix to Annex  9: 
……………………… (G B) using the vehicle or trailer method2" E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
7 Paragraphs 8.3. (for mer) , 8.4. and 8.4.1. , renumber as 8.4. , 8.5. and 8.5.1. , respectively.  
Annex 2 , Appendix 1 , amend to read:  
"Annex 2 - Appendix 1  
  Examples of separate UN Regulation No. 117 approval marks  
Example 1  
 
The above approval mark, affixed to a tyre shows that the tyre concerned has been 
approved in the Netherlands (E4) pursuant to UN Regulation No.  117 (marked by S2 (rolling 
sound emission at stage 2) ), under approval number  0312345. The first two digits of the 
approval number (03) indicate that  the approval was granted according to the requirements 
of the 03  series of amendments to this Regulation.  
Example 2  
 
 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E4) pursuant to UN Regulation No.  117 (marked by S2 (rolling sound emission 
at stage 2), W (wet adhesion of tyres in new state), R2 (rolling resistance at stage 2) and B 
(wet adhesion of tyres in worn state)) under approval number  0312345. The first two digits 
of the approva l number (03) indicate that the approval was granted according to the 
requirements of the 03  series of amendments to this Regulation. " 
Annex 2 , Appendix 2 , amend to read:  
"Annex 2 - Appendix 2  
  Approval according to UN Regulation No. 117 coincident 
with approval of UN Regulations Nos.  30 or 541 
  
 1 Approvals in accordance with UN Regulation No. 117 for tyres wit hin the scope of UN 
Regulation  No. 54 currently do not include the requirement on adhesion of tyres in worn state on wet 
surfaces.  
0312345 S 2 
0312345 S2WR2 B E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
8 Example 1  
 
     a/3     0312345 S 2    0236378  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E4) pursuant to UN Regulation No.  117 (marked by "S2" (rolling sound 
emission at stage 2)), under approval number  0312345 and UN Regulation No.  30, under 
approval number  0236378. The first two digits of the approval numbers ("03" and "02") 
indicate that the approval pursuant to UN Regulation No.  117 was granted according to  the 
03 series of amendments and the approval pursuant to UN Regulation No.  30 according to 
the 02  series of amendments.  
Example 2  
 
0312345 S2WR2B   0236378  
or 
0312345 S2WR2B  
0236378  
The above approval mark shows that the tyre concerned has been approv ed in the 
Netherlands (E4) pursuant to UN Regulation No.  117 (marked by "S2WR2B" (rolling sound 
emission at stage 2, wet adhesion of tyres in new state, rolling resistance at stage 2 and wet 
adhesion of tyres in worn state)), under approval number  0312345 and UN Regulation No.  30 
under approval number  0236378. The first two digits of the approval numbers ("03" and 
"02") indicate that the approval pursuant to UN Regulation No.  117 was granted according 
to the 03  series of amendments and the approval pursuant  to UN Regulation No.  30 according 
to the 02  series of amendments.  
Example 3  
 
a/3     0312345 S2WR2   0065432  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E4) pursuant to UN Regulation No.  117 (marked by "S2WR2" (rolling sound 
emission at stage 2, wet adhesion of tyres in new state and rolling resistance at stage 2)),  
under approval number  0312345 and UN Regulation No.  54 under approval 
number  0065432. The first two digits of the approval numbers ("03" and "00") indicate that 
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
9 the approval pursuant to UN Regulation No.  117 was granted according to the 03  series of 
amend ments and the approval pursuant to UN Regulation No.  54 according to its original 
form. " 
Annex 2 , Appendix 3 , amend to read:  
"Annex 2 - Appendix 3  
  Combinations of markings of approvals issued in accordance 
with Regulations Nos. 117, 30 or 54 2 
Example 1 
 
a/3    0236378 + 03S2  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E4) pursuant to UN Regulation No.  30 according to its 02  series of amendments 
(indicated by the first two digits of the approval number, "02") under approval 
number  0236378. It is also marked by "+  03S2" which indicates that the tyre was also 
approved pursuant to UN Regulation No.  117 (03  series of amendments) for S (rolling sound 
emission at stage 2).  
Example 2  
 
 
a/3    0236378 +  03S2WR2B  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E4) pursuant to UN Regulation No.  30 according to its 02  series of amendments 
(indicated by the first two digits of the approval number, "02") under approval 
number  0236378. It is also marked by "+  03S2WR2B" which indicates that the tyre was also 
approved pursuant to UN Regulation No.  117 (03  series of amendments) for S (rolling sound 
emission at stage 2) W (wet adhesion of tyres in new state), R (roll ing resistance at stage 2) 
and B (wet adhesion of tyres in worn state). "  
Annex 2 , Appendix 4 , amend to read:  
"Annex 2 - Appendix 4  
  Extensions to combine approvals issued in accordance with 
Regulation No. 117  
  
 2 Approvals in accordance with UN Regulation No. 117 for tyres within the scope of UN 
Regulation  No. 54 currently do not inc lude the requirement on adhesion of tyres in worn state on wet 
surfaces.  
E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
10 Example 1  
 
 
a/3    0212345 S2WR2 + 03B  
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E4) pursuant to UN Regulation No.  117 and the 02  series of amendments 
under approval number  0212345. The marking is complemented by S2WR2 (rolling sound 
emission at stage 2) W (wet adhesion of tyres in new state) and R (rolling resistance at 
stage  2) The "03B" preceded by "+" indicates that it has had its approval extended under UN 
Regulation No.  117 and 03  series of amendments to wet adhesion of tyres in w orn state based 
on separate certificate. " 
Annex 5,  title, amend to read : 
  "Test procedure s for measuring the adhesion on wet surfaces 
of tyres in new state " 
Annex 5 – Appendix, amend to read : 
  "Test reports examples of wet grip index  for tyres in new 
state  
Example 1:  Test report of wet grip index for tyres in new state  using  trailer or tyre test 
vehicle method  
… 
Example 2:  Test report of wet grip index for tyres in new state using vehicle method  
…" 
Annex 7,  
Appendix 3, Part I, paragraph 7. , amend to read:  
"7.  Snow grip index relative to SRTT according to paragraph 6.5.1.1. " 
Insert a new Annex 9, to read : 
"Annex 9  
Test procedure for measuring the adhesion on wet surfaces of 
tyres in worn state  
1. General part (reserved)  
2. Tyres of class C1  
Principle  
Two steps:  
1) Preparation of the tyre in worn state  
2) Wet grip index evaluation of the tyre in worn state  
2.1. Definitions  
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
11 For the purpose of this Annex, the "Candidate tyre " or "Candidate tyre set " 
and the " Reference tyre " or "Reference tyre set ” mentioned in  paragraphs 
2.19.2. and 2.19.3. shall be read respectively as " Candidate tyre in worn state " 
or "Candidate tyre set in worn state " and the " Reference tyre in worn state " or 
"Reference tyre set in worn state ". 
2.1.1.  "Tyre in worn state " or " worn tyre " means, for the purpose of this Regulation, 
a new tyre artificially worn by reducing the tread depth at the height of the 
tread -wear indicator as defined in the UN Regulation No. 30 (1.6 +0.6 / −0.0 
mm).  
2.1.2.  "Tyre in new state " means a new tyre before starting to be artificially worn.  
2.1.3.  "Groove " means the space between two adjacent ribs or blocks in the tread 
pattern.  
2.1.4.  "Groove depth " means  the perpendicular distance from a real or calc ulated 
reference plane defined by edges of two adjacent ribs to the lowest point in the 
groove.  
2.1.5.  "Reference tread width " (C) is calculated as follows : 
𝐶=(1.075 −0.005 ∙𝑅𝑎)∙𝑆11.001 
Where:  
Ra is the nominal aspect ratio as defined as part of tyre size designation in 
UN Regulation No. 30 except for the sizes listed in Annex 5 of UN 
Regulation No. 30 where it is taken as 90 and  
S1 is the nominal section width according to UN Regulation No. 30 except 
for the sizes listed in Annex 5 of UN Regulation No. 30 where it is the 
tyre section width listed therein.  
2.1.6.  "Tread -wear indicators ": see definition in UN Regulation No.  30. 
2.1.7.  "Centre line " means the line dividing the overall width of the tyre in two equal 
parts.   
2.1.8.  "Central zone " means the area on the tread width defined by the ¾ (75%) of 
the reference tread width ( C) symmetrically measured from the centre line.  
2.1.9.  "Shoulder zone " means the area on both sides of the tread outside of the central 
zone.  
2.1.10.  "Moul d parting line " means the  border circumference in which mould tread 
pattern segments connects with mould sidewall plates. If no mould parting line 
is visible on the tyre, a virtual mould parting line shall be considered as the 
circumferential line in the e quivalent position at the end of the shoulder 
grooves.  
2.1.11.  "Tread pattern  limit points Li and Le " means the  points located on the tyre 
profile between mould parting line and hypothetical point up to 15 mm on the 
tyre profile towards centre line (see Fi gure 1).  
 
Figure 1  
Li (Le) zone  
Mould parting line  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
12 2.1.12.  "Buffing " is all the processes of removing material from the tread to prepare 
the tyre in worn state for following the procedure in paragraph 2.2.1.  
2.1.13. "Reference tyre in worn state " or "Reference tyre set in worn state " means a 
tyre or a tyre set of Standard Reference Test Tyres SRTT16 in worn state.  
2.2.  Theoretical target profile of a tyre at worn state   
The theoretical target profile is the profile curve of the tyre in worn state, as 
described in paragraph 2.2.1.2.2.  
2.2.1.  Preparation of class C1 tyres in worn state  
 The following paragraphs outline the preparation of worn tyres of class C1 by 
removal of a predetermined amount of tread rubber (for example cutting, 
grinding, surface finish) for subsequent wet grip index testing.  
2.2.1.1.  Apparatus  
2.2.1.1.1.  Tread Depth Gauge.  
 Any mechanical, optical, or electronic device capable of measuring groove 
(void) depth can be used. The resolution of the gauge shall be at least 0.02  mm. 
The accuracy of the gauge shall be to within ±0.04 mm.  
2.2.1.1.2.  Tyre Tread Removal Machine, with equipment to remove tread rubber in a 
predetermined manner. Specifically, the equipment shall ensure a buffing 
accuracy and precision on the final groov e depth as required in the paragraph 
2.2.1.2.4.1.  
2.2.1.2.  Procedure  
Choose 4 positions approximately equally spaced around the circumference.  
 
Figure 2  
At each of the four positions, choose measurement points in the transversal 
direction:  
• In the central zone pursuant to the procedure described in paragraph 
2.2.1.2.1. and  
• In each shoulder zone at least one measurement point.  
2.2.1.2.1.  Choice of the control measurement points of the central zone  
To control the conformity of the preparation proces s (see paragraph 2.2.1.2.3., 
choose n measurement points in the central zone, in the transversal direction 
(see Figure 2)  
• The number of measurement points n shall be greater than or equal to 
4; */ 
• 1 measurement point in each principal groove;  
• The other measurement points shall be located in non -principal 
grooves:  
o At the maximum groove depth in the corresponding 
groove/zone;  
o In order to have the most regular distribution of the n points.  
E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
13 */ In case a tyre tread pattern does not allow the mea surement at 4 points in the 
central zone, the groove depth may be measured at 3 measurement points. In 
case that 3 measurement points in transversal direction are not available, the 
number and position of the measurement points shall be agreed with the Typ e 
Approval Authority.  
Measurement points in the principal grooves shall be positioned at locations 
with full groove depth, for example, avoiding rubber ridges, tie bars, treadwear 
indicators and other elevated elements.  
 
Figure 3  
2.2.1.2.2.  Description of theoretical worn target profile  
Central zone: curve built on a circle with its centre located on the radial axle 
passing through the centre line and its radius built on a fit on all the points 
located at 2 mm height on all the control points  as described in paragraph 
2.2.1.2.1. Alternatively, depending of the specificity of the tread pattern 
geometry, the fitting curve can be the offset of the original tyre profile.  
Shoulder zone: edges of the artificial worn profile in the central part of th e 
tread are connected with Le and Li points. Regularity of the whole artificial 
worn tyre profile (on the of the central zone to the shoulders) shall be assured 
(for example by an arc of circumference or another curve).  
 
Figure 4  
2.2.1.2.3.  Preparation of the worn tyre.  
Inspect the tyre to determine that there are no tread defects that would affect 
the finished tyre. If such conditions are noted, do not use the tyre for this 
procedure.  
Depending on the worn tyre preparation processing technique, the removing 
of the rubber can be managed by directly targeting the worn tyre target profile, 
or by a manual regular controlling of the rubber removal, or oth er means.  
2.2.1.2.4.  Validation of the prepared tyre  
2.2.1.2.4.1.  Validation of tread depths  
At the end of the preparation process, measure the groove depth at the 
measurement points defined in paragraph 2.2.1.2.1.  
Centre of  
the circle  
Centre line  
Li 
 Le 
Shoulder zone  
 Central zone  
 Shoulder zone  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
14 For all the measurement points defined in the central zone:  
• The final groove depth at each individual measurement point of the 
central zone shall be 2  mm ±  0.4 mm  
• The average groove depth over all measurement points in the central 
zone shall be 2  mm ±  0.2 mm 
For each measurement point defined in the shoulder zone:  
• The final groove depth in the shoulder zone shall not be greater than 
2 mm. 
 
 
 
Figure 5  
If one of the above conditions is not met, another candidate tyre shall be 
prepared.  
2.2.1.2.4.2.  Validation of the surface of the worn tyre  
The arithmetical mean height of the absolute values of the roughness profile, 
as defined in ISO 21920 -2:2021, of the final surface shall be determined at 3 
measurement points in the transversal direction approximately equally spaced 
on the prepared surface, at 4 circumferential positions equally spaced.  
The average of the 3 arithmetical mean height of the absolute values of the 
roughness profile of the final surface shall not exce ed 20 µm.  
If the above condition is not met, another candidate tyre shall be prepared.  
2.3. General test conditions  
2.3.1.  Track characteristics  
The test track shall have the following characteristics:  
2.3.1.1.  The surface shall have a dense asphalt surfa ce with a uniform gradient of not 
more than 2 per cent in both longitudinal and lateral directions and shall not 
deviate more than 6 mm when tested with a 3 m straight edge.  
2.3.1.2.  The surface shall have a pavement of uniform age, composition, and wear. The 
test surface shall be free of loose material and foreign deposits.  
2.3.1.3.  The maximum chipping size shall be 10 mm (tolerances permitted from 8  mm 
to 13 mm).  
2.3.1.4.  The average macro texture depth as measured in accordance wi th ASTM E965 -
96 (Reapproved 2006) by a sand patch shall be (0.7 ± 0.3) mm. In case the 
vehicle method is used, the average macro texture depth shall be determined 
in both lanes where the tyres are going to brake.  
2 mm ± 0.4 mm  
2 mm ± 0.2 in average   (𝟒∙𝒏) 
≤ 2 mm  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
15 2.3.1.5.  The wetted frictional properties o f the surface shall be measured using the 
Worn Standard Reference Test Tyre SRTT16 in worn state either with the 
method described in paragraph 2.3.2.1 . of this Annex in case the vehicle 
method (according to paragraph 2.4.1. below) is used, or with the meth od 
described in paragraph 2.3.2.2 . in this Annex in case the trailer (or tyre test 
vehicle) method is used.  
2.3.2.  Methods to measure the wetted frictional properties of the surface  
2.3.2.1.  Using the procedure described in paragraph  2.4.1. of this Annex, perform two 
braking tests of the reference tyre, each consisting of at least six (6) valid test 
runs in the same direction on aligned segments of the track. The braking tests 
shall cover the entire potential braking area, including where the texture depth 
was measured.  
Evaluate the braking tests as described in paragraphs  2.4.1.1.1. and 2.4.1.1.2. 
of this Annex. If the coefficient of variation of one braking test CV BFC exceeds 
4 per cent, dismiss the results and repeat the braking tests.  
For each braking te st, the arithmetic mean 𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅ of the average Braking Force 
Coefficients shall be corrected for effects of temperature as follows:  
𝐵𝐹𝐶 ave,corr =𝐵𝐹𝐶 ave̅̅̅̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
where  
ϑ is the wetted surface temperature in degrees Celsius,  
𝑎= 0.002  ℃ −1 and 𝜗0=20 ℃ . 
For each braking test, the temperature -corrected average Braking Force 
Coefficient ( BFC ave,corr ) shall be not less than 0.4 and not greater than.0.65  
The arithmetic means of the temperature -corrected average Braking Force 
Coefficients of the two braking tests shall not differ by more than 10  per cent 
of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 ave,corr )=2∙|𝐵𝐹𝐶 ave,corr,1 −𝐵𝐹𝐶 ave,corr,2
𝐵𝐹𝐶 ave,corr,1 +𝐵𝐹𝐶 ave,corr,2|≤10 % 
2.3.2.2.  Using the procedure described in paragraph  2.4.2. of this Annex, perform in 
the same area where the average macro texture depth was measured one 
braking test of the reference tyre, consisting of at least six (6) test runs in the 
same direction.  
 Evaluate the braking test as described in paragraphs  2.4.2.1.1. and 2.4.2.1.2. of 
this Annex. If the coefficient of variation CV µ exceeds 4  per cent, dismiss the 
results and repeat the braking test.  
 The arithmetic mean ( 𝜇peak̅̅̅̅̅) of the measured peak braking force coefficients 
shall be corrected for effects of temperature as follows:  
𝜇peak,corr =𝜇peak̅̅̅̅̅̅+𝑎∙(𝜗−𝜗0) 
 Where  
ϑ is the wetted road surface temperature in degrees Celsius  
𝑎= 0.002  ℃ −1  and  𝜗0=20 ℃. 
The temperature corrected average peak braking force coefficient  (µpeak,corr ) 
shall be not less than 0.45 and not greater than 0.80.  
2.3.3.  Atmospheric conditions  
 The wind conditions shall not interfere with wetting of the surface (wind -
shields are allowed).  
 The wetted surface temperature and the ambient temperature shall be between:  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
16  
Category of use  Wetted surface 
temperature  Ambient temperature  
Normal tyres  12 °C – 35 °C  12 °C – 40 °C  
Snow tyres  5 °C – 35 °C  5 °C – 40 °C  
 Snow tyres for use in severe 
snow conditions  5 °C – 20 °C  5 °C – 20 °C  
Special use tyres  not applicable  not applicable  
 
 Moreover, the wetted surface temperature shall not vary during the test by 
more than 10  °C. 
 The ambient temperature shall remain close to the wetted surface temperature; 
the difference between the ambient and the wetted surface temperatures shall 
be less than 10 °C.  
2.3.4.  Replacement of reference tyr es 
 When  irregular wear or damage results from tests, or when wear or aging 
influences the test results, the use of the reference tyre shall be discontinued.  
2.4. Testing methods for measuring the adhesion on wet surfaces  
For the calculation of the wet grip index (G B) of a candidate tyre in worn state, 
the wet grip braking performance of the candidate tyre is compared to the wet 
grip braking performance of the reference tyre on a vehicle travelling straight 
ahead on a wet, paved surface. It is measured with one of the following 
methods:  
(a) Vehicle method consisting of testing a set of tyres mounted on an 
instrumented passenger car;  
(b) Testing method using a trailer towed by a vehicle or a tyre test vehicle, 
equipped with the test tyre(s).  
2.4.1. Testing method (a) using an instrumented passenger car  
All the provisions specified in Annex 5, Part (A), paragraph 4.1. "Testing 
method (a) using an instrumented passenger car" and its subparagraphs apply 
with the exception of paragraph 4.1.6. "Proces sing of measurement results". 
The paragraph 2.4.1.1. of this Annex applies instead.  
2.4.1.1.  Processing of measurement results  
2.4.1.1.1.  Calculation of the average braking force coefficient   
All the provisions specified in Annex 5, Part (A), paragraph 4.1 .6.1. apply.  
2.4.1.1. 2. Validation  of results  
 The coefficient of variation CV BFC is calculated as follows:  
𝐶𝑉𝐵𝐹𝐶 =100% ∙𝜎𝐵𝐹𝐶
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅ 
where  
 𝜎𝐵𝐹𝐶 =√1
𝑁−1∑ (𝐵𝐹𝐶 𝑎𝑣𝑒 ,𝑗−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample 
standard deviation and  
𝐵𝐹𝐶𝑎𝑣𝑒̅̅̅̅̅̅̅̅  the arithmetic mean of the average braking force coefficients BFC ave,j 
of N test runs.  E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
17  For the reference tyre:  
(a) The coefficient of variation CV BFC of the initial and the final braking 
test of the reference tyre within one test cycle shall be less than or equal 
to 4 per cent.  
(b) The arithmetic means of the average braking force coefficients of the 
initial and the final braking test shall not differ by more than [5]  per 
cent of the average of the two values:  
𝐶𝑉𝑎𝑙 (𝐵𝐹𝐶 𝑎𝑣𝑒)=100 %∙ 2∙|𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)−𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri)+𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf)|≤[5]% 
where  
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Ri) and 𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(Rf) are the arithmetic means of the average 
braking force coefficie nts respectively in the initial and final braking 
tests of the reference tyre within a test cycle.  
(c) The temperature -corrected average braking force coefficients 
(BFC ave,corr , see paragraph  2.3.2.1.  of this Annex) as calculated from the 
initial and from the final braking tests of the reference tyre within a test 
cycle shall be not less than 0. 40 and not greater than 0. 65. 
If one or more of the above conditions is not met, the complete test cycle shall 
be performed again.  
 For the candidate tyres (T):  
  The coefficient of variation CV BFC is calculated for each candidate tyre set. If 
one coefficient of variation is higher than 4 per cent, the data shall be discarded 
and the braking test repeated for that candidate tyre set.  
2.4.1.1.3.  Calculation of adjusted average braking force coefficien t 
All the provisions specified in Annex 5, Part (A), paragraph 4.1.6.3. apply.  
2.4.1.1.4.  Calculation  of the wet grip index of the candidate tyre  
 The wet grip index GB(Tn) of the candidate tyre T n (n = 1, 2 or 3) is calculated 
as follows:  
𝐺𝐵(T𝑛)=𝐾vehicle ∙{𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛)−[𝑎∙∆𝐵𝐹𝐶 (R)+𝑏∙∆𝜗+𝑐∙(∆𝜗)2+𝑑∙∆𝑀𝑇𝐷 ]} 
where : 
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅(T𝑛) is the arithmetic mean of the average braking force coefficients 
of the candidate tyre T n within a braking test;  
∆𝐵𝐹𝐶 (𝑅)=𝐵𝐹𝐶 𝑎𝑑𝑗(𝑅)−𝐵𝐹𝐶 (𝑅0) 
BFC adj(R) is the adjusted average braking force coefficient in accordance 
with Table  1; 
BFC (R0) = 0. 52 is fixed as the braking force coefficient for the reference tyre 
in the reference conditi ons; 
∆𝜗=𝜗−𝜗0 
ϑ is the measured wet surface temperature in degrees Celsius when 
the candidate tyre T n is tested;  
ϑ0 is the wetted surface reference temperature for the candidate tyre 
according to its category of use as listed in Table  2; 
∆𝑀𝑇𝐷 =𝑀𝑇𝐷 −𝑀𝑇𝐷 0 
MTD  is the measured macro texture depth in mm of the track (see 
paragraph  3.1.4. of this Annex);  
MTD 0 = 0.8  mm is the macro texture depth of the reference track;  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
18 Kvehicle  = 1.95 is a factor to grant consistency between previous calculation of 
the wet grip index and this one, and to ensure convergence 
between vehicle and trailer method and  
coefficients a, b, c and d are given in Table  2. 
Table  2 
Category of use  ϑ0 
(°C) a 
 b 
(°C−1) c 
(°C−2) d 
(mm−1) 
Normal tyre  20 +0.90996  -0.00179  -0.00013  -0.10313  
Snow tyre  15 +0.81045  -0.00004  -0.00019  -0.05093  
 Snow tyre for use in 
severe snow conditions  10 +0.71094  +0.00172  -0.00025  +0.00127  
Special use tyre  not defined  
2.4.2.  Testing  method (b) using a trailer towed by a vehicle or a tyre test vehicle  
 All the provisions specified in Annex 5, Part (A), paragraph 4.2. " Testing  
method (b) using a trailer towed by a vehicle or a tyre test vehicle" and its 
subparagraphs apply with the exc eption of paragraph 4.2.8. "Processing of 
measurement results". The paragraph 2.4.2.1. of this Annex applies instead.  
2.4.2.1.  Processing of measurement results  
2.4.2.1.1.  Calculation of the peak braking force coefficient  
All the provisions specified in An nex 5, Part (A), paragraph 4.2.8.1. apply.  
2.4.2.1.2.  Validation of results  
 The µpeak coefficient of variation CV µ is calculated as follows:  
𝐶𝑉𝜇=100% ∙𝜎𝜇
𝜇peak̅̅̅̅̅̅ 
where  
𝜎µ=√1
𝑁−1∑ (𝜇peak ,𝑗−𝜇peak̅̅̅̅̅̅)2𝑁
𝑗=1  denotes the corrected sample standard 
deviation and  
𝜇peak̅̅̅̅̅̅ the arithmetic mean of the peak braking force coefficients ( 𝜇peak ,𝑗) of N 
test runs.  
 For the reference tyre (R):  
(a) The coefficients of variation CVμ of the initial and the final braking tests  
of the reference tyre within one test cycle shall be less than or equal to 
4 per cent;  
(b) The arithmetic mean of the peak braking force coefficients of initial and 
the final braking test of the reference tyre within one test cycle shall not 
differ by mor e than 5  per cent of the average of the two values:  
𝐶𝑉𝑎𝑙 (µ𝑝𝑒𝑎𝑘 )=100 %∙ 2∙|µ𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)−µ𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)
µ𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri)+µ𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf)|≤5% 
where  
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Ri) and 𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(Rf) are the arithmetic means of the peak 
braking force coefficients respectively in the initial and final braking 
tests of the reference tyre within a test cycle;  
(c) The temperature -corrected average peak braking force coefficients 
(µpeak,corr , see paragraph 2.3.2.2. of this Annex) as calculated from the E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
19 initial and from the final braking test of the reference tyre within a test 
cycle shall be not less than 0. 45 and not greater than 0. 80. 
If one or more of the above conditions is not met, the complete test cyc le shall 
be performed again.  
 For the candidate tyre(s) (T n): 
 The coefficient of variation of the peak braking force coefficient CV µ is 
calculated for each candidate tyre. If one coefficient of variation is greater than 
5 per cent, the data shall be discarded and the braking test repeated for this 
candidate tyre.  
2.4.2.1.3.  Calculation of the adjusted average peak braking force coefficient of the 
reference tyre  
All the provisions specified in Annex 5, Part (A), paragraph 4.2.8.3. apply.  
2.4.2.1.4.  Calculation of the wet grip index of the candidate tyre  
 The wet grip index GB(Tn) of the candidate tyre T n (n = 1, 2, 3) is calculated as 
follows:  
𝐺𝐵(T𝑛)=𝐾trailer ∙{𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(T𝑛)−[𝑎∙∆𝜇𝑝𝑒𝑎𝑘 (R)+𝑏∙∆𝜗+𝑐∙(∆𝜗)2+𝑑∙∆𝑀𝑇𝐷 ]} 
where:  
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅(T𝑛) is the arithmetic mean of the peak braking force coefficients of 
the candidate tyre T n within a braking test;  
∆𝜇𝑝𝑒𝑎𝑘 (R)=𝜇𝑝𝑒𝑎𝑘 ,𝑎𝑑𝑗(R)−𝜇𝑝𝑒𝑎𝑘 (𝑅0) 
µpeak,adj (R) is the adjusted peak braking force coefficient in accordance with 
Table  3; 
µpeak(R0) = 0. 71 is fixed as the peak braking force coefficient for the reference 
tyre in the reference conditions;  
∆𝜗=𝜗−𝜗0 
ϑ  is the measured wet surface temperature in degrees Celsius when 
the candidate tyre T n is tested;  
ϑ0  is the wetted su rface reference temperature for the candidate tyre 
according to its sidewall marking as listed in Table 4;  
∆𝑀𝑇𝐷 =𝑀𝑇𝐷 −𝑀𝑇𝐷 0 
MTD  is the measured macro texture depth of the track  
MTD 0 = 0.8  mm is fixed as the macro texture depth of the reference track;  
Ktrailer = 1.50  is a factor to grant consistency between previous calculation of 
the wet grip index and this one, and to ensure convergence 
between vehicle and trailer method and  
 coefficient s a, b, c and d are given in Table 4.  
Table 4  
Category of use  ϑ0 
(°C) a 
 b 
(°C−1) c 
(°C−2) d 
(mm−1) 
Normal tyre  20 +0.99655  -0.00124  +0.00041  +0.06876  
Snow tyre  15 +0.94572  -0.00032  -0.00020  +0.08047  
 Snow tyre for use in 
severe snow conditions  10 +0.89488  +0.00061  -0.00080  +0.09217  
Special use tyre  not defined  E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
20 ” 
Insert a new Annex 9 – Appendix 1, to read : 
“Annex 9 – Appendix 1  
  Worn tyre preparation report example  
   
Date of buffing    
Manufacturer    
Brand    
Trade description/commercial name   
Size   
Service description   
Rim width   
Inflation pressure (kPa)   
Week of manufacture    
Tyre identification code    
 
  Groove depth measurement  
Groove depth  
Central zone: (2.0 ± 0.4)  mm 
Shoulder zone: ≤ 2 mm  in central zone 
(yes/no)  Circumferential locations  
1 2 3 4 Transversal locations  1           
2          
3          
4          
5          
6          
7          
8           
 
 
       
Values   
Average groove depth in central zone (mm)  
Central zone: (2.0 ± 0.2)  mm   
 
  Roughness measurement  
Arithmetic al mean height of the absolute 
values  of the roughness profile (µm)  Sections  
1 2 3 4 Trans. Loc.  
1 (right)      
2 (center)      
3 (left)      
Average      
 
Average of the arithmetic al mean height of the  absolute 
values of the  roughness profiles (µm)    
" E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
21 Insert a new Annex 9 – Appendix 2, to read : 
"Annex 9 – Appendix 2  
  Test reports examples of wet grip index for tyres in worn 
state  
Example 1: Test report of wet grip index for tyres in worn state using trailer or tyre test 
vehicle method  
Test report number:    Test date:   
      
Track:     Minimum:  Maximum:  
Texture depth 
(mm):    Wetted surface temp. 
(°C):    
µpeak,corr :   Ambient temp (°C):    
Water depth (mm):       
      
Speed (km/h):       
 
No. 1 2 3 4 5 
Brand       
Pattern/trade 
description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) 
inflation pressure (kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       
Rim      
Load (kg)       
Pressure (kPa)       
µpeak 1      
2      
3      
4      
5      
6      
7      
8      
𝜇𝑝𝑒𝑎𝑘̅̅̅̅̅̅̅       
Standard deviation, σµ      
CV µ ≤ 4 %       
CVal (µpeak) ≤ 5 %       E/ECE/324/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev. 4/Amend. 7 
22 No. 1 2 3 4 5 
µpeak,corr (R)      
µpeak,adj (R)      
Wet grip index       
Wetted surface temp. 
(°C)      
Ambient temp. (°C)       
Remarks       
 
Example 2: Test report of wet grip index for tyres in worn state using vehicle method  
Test report number:    Test date:   
      
Track:     Minimum:  Maximum:   Vehicle   
Texture depth 
(mm):    Wetted surface temp. 
(°C):     Brand:   
BFC ave,corr,1 :   Ambient temp (°C):     Model:   
BFC ave,corr,2 :       Type:   
CVal (BFC ave,corr ):       Year of 
registration:   
Water depth (mm):        Maximum axle 
load:  Front  Rear  
         
Initial speed (km/h):    Final speed (km/h):      
 
No. 1 2 3 4 5 
Brand       
Pattern/trade 
description  SRTT…     SRTT…  
Size      
Service description       
Reference (test) 
inflation pressure (kPa)       
Tyre identification       
M+S marking (Y/N)       
3PMSF marking (Y/N)       
Rim      
Front axle pressure 
(kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle pressure 
(kPa)  left: right:  left: right:  left: right:  left: right:  left: right:  
Front axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
Rear axle load (kg)  left: right:  left: right:  left: right:  left: right:  left: right:  
 Braking 
distance  
(m) BFC i Braking 
distance 
(m) BFC i Braking  
distance 
(m) BFC i Braking 
distance 
(m) BFC i Braking 
distance 
(m) BFC i 
Measurement  1           
 2           
 3           
 4           
 5           
 6           E/ECE/324/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
E/ECE/TRANS/505/ Rev.2/ Add. 116/Rev.4 /Amend. 7 
23 No. 1 2 3 4 5 
 7           
 8           
 9           
 10           
𝐵𝐹𝐶 𝑎𝑣𝑒̅̅̅̅̅̅̅̅̅̅       
Standard deviation, 
σBFC      
CV BFC ≤ 4 %       
CVal (BFC ave) ≤ 5 %       
BFC ave,corr (R)      
BFC adj(R)      
Wet grip index       
Wetted surface temp. 
(°C)      
Ambient temp. (°C)       
Remarks       
" 
    
 
    Agreement 
  Concerning the Adoption of Uniform Technical Prescriptions for 
Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be 
Used on W heeled Vehicles and the Conditions for Reciprocal 
R
ecognition of Approvals Granted on the Basis of these Prescriptions * 
(
Revision 2, including the amendments which entered into force on 16 October 1995) 
  Addendum 116: Regulation No. 117 
  Revision 4 
I
ncorporating all valid text up to: 
Corrigendum 4 to 02 series of amendments – Date of entry into force: 12 March 2014 
Corrigendum 5 to 02 series of amendments (Russian only)  – Date of entry into force: 12 March 2014 
Supplement 5 to the 02 series of amendments – Date of entry into force: 10 June 2014 
Supplement 6 to the 02 series of amendments – Date of entry into force: 9 October 2014 
Supplement 7 to the 02 series of amendments – Date of entry into force: 8 October 2015 
Supplement 8 to the 02 series of amendments – Date of entry into force: 20 January 2016  
Uniform provisions concerning the approval of tyres with regard to 
rolling sound emissions and/or to adhesion on wet surfaces and/or to 
r
olling resistance 
This document is meant purely as documentation tool. The authentic and legal binding texts of the 
supplements and the corrigenda are listed on the following page. 
___________ 
UNITED NATIONS 
  
 * Former title of the Agreement: 
  Agreement Concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition 
of Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958.  E/ECE/324/Rev.2/Add.116/Rev. 4−E/ECE/TRANS/505/Rev.2/Add.116/Rev. 4 
   
 
 
16 February 2016  
 
 
 
The authentic and legal binding texts of the supplements and the corrigenda are:   
 
- ECE/TRANS/WP.29/2013/59 
- ECE/TRANS/WP.29/2014/4 
- ECE/TRANS/WP.29/2014/6 
- ECE/TRANS/WP.29/2013/66 (as amended by paragraph 56 of the report ECE/TRANS/WP.29/1108) 
- ECE/TRANS/WP.29/2015/5 
- ECE/TRANS/WP.29/2015/65 (as amended by paragraph 66 of the report ECE/TRANS/WP.29/1116). 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
3 Regulation No. 117 
  Uniform provisions concerning the approval of tyres with 
regard to rolling sound emissions and/or to adhesion on wet 
surfaces and/or to rolling resistance 
Contents 
 Page  
Regulation 
1. Scope ..................................................................................................................................................   5  
2. Definitions ..........................................................................................................................................  5  
3. Application for approval .....................................................................................................................   9  
4. Markings .............................................................................................................................................   11 
5. Approval .............................................................................................................................................   11 
6. Specifications ......................................................................................................................................  13 
7. Modifications of the type of pneumatic tyre and   extension of approval ...........................................  18 
8. Conformity of production ...................................................................................................................   18 
9. Penalties for non-conformity of production ........................................................................................   19 
10. Production definitively discontinued ..................................................................................................  19 
11. Names and addresses of Technical Services    responsible for conducting approval  
tests of Type Approval Authorities .....................................................................................................  20 
12. Transitional provisions .......................................................................................................................   20 
Annex es 
1 Communication ...................................................................................................................................  22 
2  Appendix 1 -  Example of approval marks ....................................................................................   24 
Appendix 2 -  Approval according to Regulation No. 117 coincident with  
approval of Regulation No. 30 or 54 ......................................................................  25 
Appendix 3 - Extensions to combine approvals issued in accordance with  
Regulations Nos. 117, 30 or 54 ...............................................................................   28 
Appendix 4 -  Extensions to combine approvals issued in accordance with  
Regulation No. 117 ................................................................................................ .  29 
3 Coast-by test method for measuring tyre-rolling sound emission .......................................................   31 
Appendix 1 -  Test report ...............................................................................................................   38 
4 Specifications for the test site .............................................................................................................   40 
5 Test procedures for measuring wet grip ..............................................................................................   47 
 Appendix - Test reports examples of wet grip index ................................................................ .  73 E/ECE/324/Rev.2/Add.116/Rev.3 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.3 
 
4 6 Test procedure for measuring rolling resistance .................................................................................   75 
Appendix 1 -  Test equipment tolerances ......................................................................................   86 
Appendix 2 -  Measuring rim width ...............................................................................................   89 
Appendix 3 -  Test report and test data (Rolling resistance) ..........................................................   90 
Appendix 4 -  Tyre standards organizations ..................................................................................   91 
Appendix 5 -  Deceleration method: Measurements and data processing for deceleration  
value obtaining in differential form dω/dt.  .............................................................   92 
7 Procedures for snow performance testing relative to snow tyre for use in severe snow conditions ...  95 
Appendix 1 -  Pictogram definition of "Alpine Symbol" ...............................................................   107 
Appendix 2 -  Test reports and test data for C1 and C2 tyres ........................................................   108 
Appendix 3 -  Test reports and test data for C3 tyres .....................................................................  110 
 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
5   1.  Scope 
1.1. This Regulation applies to new pneumatic tyres of Classes C1, C2 and C3 
with regard to their sound emissions, rolling resistance and to adhesion 
performance on wet surfaces (wet adhesion). It does not, however, apply to: 
1.1.1. Tyres designed as "Temporary use spare tyres" and marked "Temporary use 
only"; 
1.1.2. Tyres having a nominal rim diameter code ≤  10 (or ≤  254 mm) or ≥  25 
(or ≥ 635 mm); 
1.1.3. Tyres designed for competitions; 
1.1.4. Tyres intended to be fitted to road vehicles of categories other than M, N 
and O;1 
1.1.5. Tyres fitted with additional devices to improve traction properties 
(e.g. studded tyres); 
1.1.6. Tyres with a speed rating less than 80 km/h (speed symbol F); 
1.1.7. Tyres designed only to be fitted to vehicles registered for the first time before 
1 October 1990. 
1.1.8. Professional off-road tyres.  
1.2. Contracting Parties shall issue or accept approvals to rolling sound and/or 
wet adhesion and/or rolling resistance. 
  2.  Definitions 
For the purpose of this Regulation, in addition to the definitions contained in 
Regulations Nos. 30 and 54, the following definitions apply. 
2.1. " Type of tyre " means, in relation to this Regulation, a range of tyres 
consisting of a list of tyre size designations, brand names and trade 
descriptions, which do not differ in such essential characteristics as: 
(a) The manufacturer's name; 
(b) The tyre class (see paragraph 2.4. below ); 
(c) The tyre structure; 
(d) The category of use: normal tyre, snow tyre and special use tyre; 
(e) For Class C1 tyres: 
(i) In case of tyres submitted for approval of rolling sound 
emission levels, whether normal or reinforced (or extra load); 
  
 1 As defined in the Consolidated Resolution on the Construction of Vehicles (R.E.3), document 
ECE/TRANS/WP.29/78/Rev.4, para. 2. - 
www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29resolutions.html E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
6 (ii) In case of tyres submitted for approval of performance 
adhesion on wet surfaces, whether normal tyres or snow tyres 
with a speed category of Q or below excluding H (≤ 160  km/h) 
or speed category R and above including H (> 160 km/h); 
(f) For Class es C2 and C3 tyres: 
(i) In case of tyres submitted for approval of rolling sound 
emission levels at stage 1, whether M+S marked or not; 
(ii) In case of tyres submitted for approval of rolling sound 
emission levels at stage 2, whether traction tyre or not; 
(g) The tread pattern (see paragraph 3.2.1. of this Regulation ). 
2.2. " Brand name" or " Trade description " means the identification of the tyre as 
given by the tyre manufacturer. The brand name may be the same as that of 
the manufacturer and the trade description may coincide with the trade mark. 
2.3. " Rolling sound emission " means the sound emitted from the contact between 
the tyres in motion and the road surface. 
2.4. " Tyre class" means one of the following groupings: 
2.4.1. Class C1 tyres : Tyres conforming to Regulation No. 30; 
2.4.2. Class C2 tyres : Tyres conforming to Regulation No. 54 and identified by a 
load capacity index in single formation lower or equal to 121 and a speed 
category symbol higher or equal to "N"; 
2.4.3. Class C3 tyres : Tyres conforming to Regulation No. 54 and identified by: 
(a) A load capacity index in single formation higher or equal to 122; or 
(b) A load capacity index in single formation lower or equal to 121 and a 
speed category symbol lower or equal to "M". 
2.5. " Representative tyre size " means the tyre size which is submitted to the test 
described in Annex 3 to this Regulation with regard to rolling sound 
emissions, or Annex 5 for adhesion on wet surfaces or Annex 6 for rolling 
resistance to assess the conformity for the type approval of the type of tyre, or 
Annex 7 for use in severe snow conditions. 
2.6. " Temporary-use spare tyre " means a tyre different from a tyre intended to be 
fitted to any vehicle for normal driving conditions; but intended only for 
temporary use under restricted driving conditions.  
2.7. " Tyres designed for competition " means tyres intended to be fitted to vehicles 
involved in motor sport competition and not intended for non-competitive on-
road use. 
2.8. " Normal tyre " means a tyre intended for normal on-road use. 
2.9. " Reinforced tyre " or " extra load tyre " of Class C1 means a pneumatic-tyre 
structure designed to carry more load at a higher inflation pressure than the 
load carried by the corresponding standard version tyre at the standard 
inflation pressure as specified in ISO 4000 -1:2010.2 
  
 2 Class C1 tyres correspond to "passenger car tyres" in ISO 4000-1:2010. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 7 2.10. " Traction tyre " means a tyre in Class C2 or C3 bearing the inscription 
TRACTION and intended to be fitted primarily to the drive axle(s) of a 
vehicle to maximize force transmission in various circumstances. 
2.11. " Snow tyre " means a tyre whose tread pattern, tread compound or structure is 
primarily designed to achieve in snow conditions a performance better than 
that of a normal tyre with regard to its ability to initiate or maintain vehicle 
motion. 
2.11.1. " Snow tyre for use in severe snow conditions " means a snow tyre whose tread 
pattern, tread compound or structure is specifically designed to be used in 
severe snow conditions and that fulfils the requirements of paragraph 6.4. of 
this Regulation. 
2.12. " Special use tyre " means a tyre intended for mixed use both on- and off-road 
or for other special duty. These tyres are primarily designed to initiate and 
maintain the vehicle in motion in off-road conditions. 
2.13. " Professional off-road tyre " is a special use tyre primarily used for service in 
severe off-road conditions. 
2.14. " Tread depth" means the depth of the principal grooves. 
2.14.1. " Principal grooves " means the wide circumferential grooves positioned in the 
central zone of the tyre tread, which, in the case of passenger and light truck 
(commercial) tyres, have the treadwear indicators located in the base. 
2.15. " Void to fill ratio " means the ratio between the area of voids in a reference 
surface and the area of this reference surface calculated from the mould 
drawing. 
2.16. " Standard Reference Test Tyre (SRTT)" means a tyre that is produced, 
controlled and stored in accordance with the  American Society for Testing 
and Materials (ASTM) standards 
 (a) E1136-93 (2003) for the size P195/75R14 
(b) F2872 (2011) for the size 225/75 R 16 C 
(c) F2871 (2011) for the size 245/70R19.5 
 (d) F2870 (2011) for the size 315/70R22.5. 
2.17. Wet grip or snow grip measurements – Specific definitions  
2.17.1. " Adhesion on wet surfaces " means the relative braking performance, on a wet 
surface, of a test vehicle equipped with the candidate tyre in comparison to 
that of the same test vehicle equipped with a reference tyre (SRTT). 
2.17.2. " Candidate tyre " means a tyre, representative of the type that is submitted for 
approval in accordance with this Regulation. 
2.17.3. " Control tyre " means a normal production tyre that is used to establish the 
wet grip or snow grip performance of tyre sizes unable to be fitted to the 
same vehicle as the standard reference test tyre – see paragraph 4.1.7. of 
Annex 5 and paragraph 3.4.3. of Annex 7 to this Regulation. 
2.17.4. " Wet grip index ( "G")" means the ratio between the performance of the 
candidate tyre and the performance of the standard reference test tyre. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
8 2.17.5. " Snow grip index ("SG") " means the ratio between the performance of the 
candidate tyre and the performance of the standard reference test tyre. 
2.17.6. " Peak brake force coefficient ( "pbfc") " means the maximum value of the ratio 
of braking force to vertical load on the tyre prior to wheel lock-up. 
2.17.7. " Mean fully developed deceleration ( "mfdd ")" means the average deceleration 
calculated on the basis of the measured distance recorded when decelerating a 
vehicle between two specified speeds. 
2.17.8. " Coupling (hitch) height " means the height when measured perpendicularly 
from the centre of the articulation point of the trailer towing coupling or hitch 
to the ground, when the towing vehicle and trailer are coupled together. The 
vehicle and trailer shall be standing on level pavement surface in its test 
mode complete with the appropriate tyre(s) to be used in the particular test. 
2.18. Rolling resistance measurement - Specific definitions 
2.18.1. Rolling resistance F r 
 Loss of energy (or energy consumed) per unit of distance traveled.3 
2.18.2. Rolling resistance coefficient C r 
 Ratio of the rolling resistance to the load on the tyre.4 
2.18.3. New test tyre 
 A tyre which has not been previously used in a rolling deflected test that 
raises its temperature above that generated in rolling resistance tests, and 
which has not previously been exposed to a temperature above 40 °C.5, 6 
2.18.4. Laboratory control tyre 
 Tyre used by an individual laboratory to control machine behaviour as a 
function of time.7 
2.18.5. Capped inflation 
 Process of inflating the tyre and allowing the inflation pressure to build up, as 
the tyre is warmed up while running. 
2.18.6. Parasitic loss 
 Loss of energy (or energy consumed) per unit distance excluding internal tyre 
losses, attributable to aerodynamic loss of the different rotating elements of 
the test equipment, bearing friction and other sources of systematic loss 
which may be inherent in the measurement. 
  
 3 The International System of Units (SI) unit conventionally used for the rolling resistance is the 
newton-meter per meter, which is equivalent to a drag force in newton. 
 4 The rolling resistance is expressed in newton and the load is expressed in kilo-newton. The rolling 
resistance coefficient is dimensionless. 
 5 New test tyre definition is needed to reduce potential data variation and dispersion due to tyre aging 
effects. 
 6 It is permissible to repeat an accepted test procedure. 
 7 An example of machine behaviour is drift. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 9 2.18.7. Skim test reading 
 Type of parasitic loss measurement, in which the tyre is kept rolling without 
slippage, while reducing the tyre load to a level at which energy loss within 
the tyre itself is virtually zero. 
2.18.8. Inertia or moment of inertia. 
Ratio of the torque applied to a rotating body to the rotational acceleration of 
this body.8 
2.18.9. Measurement reproducibility σ m 
 Capability of a machine to measure rolling resistance.9 
  3.  Application for approval 
3.1. The application for approval of a type of tyre with regard to this Regulation 
shall be submitted by the tyre manufacturer or by his duly accredited 
representative. It shall specify: 
3.1.1. The performance characteristics to be assessed for the tyre type; "rolling 
sound emissions level" and/or "adhesion performance level on wet surfaces" 
and/or "rolling resistance level". Tyre "snow performance level" in cases of 
"snow tyre for use in severe snow conditions"; 
3.1.2. Name of manufacturer; 
3.1.3. Name and address of applicant; 
3.1.4. Address(es) of manufacturing plant(s); 
3.1.5. Brand name(s), trade description(s), trade mark(s); 
3.1.6. Tyre class (Class C1, C2 or C3) (see paragraph 2.4. of this Regulation ); 
3.1.6.1. Section width range for Class C1 tyres (see paragraph 6.1.1. of this 
Regulation ); 
Note : This information is required only for approval with regard to rolling 
sound emission level. 
  
 8 The rotating body can be, for example, a tyre assembly or machine drum. 
 9 Measurement reproducibility σ m shall be estimated by measuring n times (where n ≥ 3), on a single 
tyre, the whole procedure described in paragraph 4. of Annex 6 as follows:  
 
 



   n
1 j2n
1 jj j m Crn1Cr1 n1
 
  Where: 
  j  = is the counter from 1 to n for the number of repetitions of each measurement for a given tyre, 
  n = number of repetitions of tyre measurements (n ≥ 3).  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
10 3.1.7. Tyre structure; 
3.1.8. For Class C1 tyres, state whether: 
(a) Reinforced (or extra load) in case of approval with regard to rolling 
sound emission level; 
(b) Speed category symbol "Q" or below (excluding "H") or "R" and 
above (including "H") in case of "snow" tyres for approval with regard 
to adhesion on wet surfaces; 
 For Classes  C2 and C3 tyres, state whether: 
(a) M+S marked in case of approval with regard to rolling sound emission 
level at stage 1; 
(b) Traction in case of approval with regard to rolling sound emission 
level at stage 2. 
3.1.9. Category of use (normal, snow, or special); 
3.1.10. A list of tyre size designations covered by this application. 
3.2. The application for approval shall be accompanied (in triplicate) by: 
3.2.1. Details of the major features, with respect to the effects on the performance 
(i.e. rolling sound emission level, adhesion on wet surfaces, rolling resistance 
and snow grip) of the tyres, including the tread pattern, included in the 
designated range of tyre sizes. This may be by means of descriptions 
supplemented by technical data, drawings, photographs and Computer 
Tomography (CT), and must be sufficient to allow the Type Approval 
Authority or Technical Service to determine whether any subsequent changes 
to the major features will adversely affect the tyre performance. The effects 
of changes to minor details of tyre construction on tyre performances will be 
evident and determined during checks on conformity of production; 
3.2.2. Drawings or photographs of the tyre sidewall, showing the information given 
in paragraph 3.1.8. above and the approval marking referred to in 
paragraph 4., shall be submitted once the production has been established, but 
no later than one year after the date of granting of type approval. 
3.2.3. In the case of applications relating to special use tyres, a copy of the mould 
drawing of the tread pattern shall be supplied in order to allow verification of 
the void- to-fill ratio. 
3.3. At the request of the Type Approval Authority, the applicant shall submit 
samples of tyres for test or copies of test reports from the Technical Services , 
communicated as given in paragraph 11. of this Regulation. 
3.4. With regard to the application, testing may be confined to a worst case 
selection, at the discretion of the Type Approval Authority or designated 
Technical Service. 
3.5. The laboratories and test facilities of a tyre manufacturer may be designated 
as an approved laboratory and the Type Approval Authority shall have the 
option of being represented during any tests. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 11   4.  Markings 
4.1. All tyres constituting the type of tyre shall be marked as prescribed by either 
Regulation No. 30 or 54, as applicable. 
4.2. In particular tyres shall bear:10 
4.2.1. The manufacturer's name or trade mark; 
4.2.2. The trade description (see paragraph 2.2. of this Regulation). However, the 
trade description is not required when it coincides with the trade mark; 
4.2.3. The tyre size designation; 
4.2.4. The inscription "REINFORCED" (or alternatively "EXTRA LOAD") if the 
tyre is classified as reinforced; 
4.2.5. The inscription "TRACTION"11 if the tyre is classified as "traction tyre"; 
4.2.6. The "Alpine" symbol ("3-peak-mountain with snowflake" conforming to the 
symbol described in Annex 7, Appendix 1) shall be added if the snow tyre is 
classified as "snow tyre for use in severe snow conditions". 
4.2.7. The inscription "MPT" (or alternatively " ML" or " ET") and /or "POR" if the 
tyre is classified in the category of use "special". 
 ET means Extra Tread, ML stands for Mining and Logging, MPT means 
Multi-Purpose Truck and POR means Professional Off-Road. 
4.3. Tyres shall provide adequate space for the approval mark as shown in 
Annex 2 to this Regulation. 
4.4. The approval mark shall be moulded into or onto the sidewall of the tyre, 
shall be clearly legible and shall be located in the lower area of the tyre on at 
least one of the sidewalls. 
4.4.1. However, in the case of tyres identified by the tyre to rim fitment 
configuration symbol "A", the marking may be located anywhere on the 
outside sidewall of the tyre. 
  5.  Approval 
5.1. If the representative tyre size of the type of tyre submitted for approval 
pursuant to this Regulation meets the requirements of paragraphs 6. and 7. 
below, approval of that type of tyre shall be granted. 
5.2. An approval number shall be assigned to the type of tyre approved. The same 
Contracting Party may not assign the same number to another type of tyre. 
5.3. Notice of approval or extension of approval or refusal of approval of a type 
of tyre pursuant to this Regulation shall be communicated to the Parties to the 
Agreement, which apply this Regulation by means of a form conforming to 
the model in Annex 1 to the Regulation. 
  
 10 Some of these requirements may be specified separately in Regulation No. 30 or 54. 
 11 Minimum height of marking: refer to dimension C in Annex 3 of Regulation No. 54. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
12 5.3.1. Tyre manufacturers are entitled to submit an application for extension of type 
approval to the requirements of other Regulations relevant to the tyre type. In 
that case, a copy of the relevant type approval communication(s), as issued 
by the relevant Type Approval Authority, shall be attached to the application 
for extension of approval. All applications for extension of approval(s) shall 
only be granted by the Type Approval Authority which issued the original 
approval for the tyr e. 
5.3.1.1. When extension of approval is granted to incorporate into the communication 
form (see Annex 1 to this Regulation) certification(s) of conformity to other 
Regulations, the approval number on the communication form shall be 
supplemented by suffix(es) to identify the given Regulation(s) and the 
technical prescriptions which have been incorporated by the extension of 
approval. In relation to each given suffix, the specific type approval 
number(s) and the Regulation itself shall be added to item 9. of Annex 1 -   
Communication form. 
5.3.1.2. The prefix shall identify the series of amendments of the prescription on tyre 
performances for the relevant Regulation, e.g. 02S2 to identify the second 
series of amendments on tyre road rolling sound emissions at stage 2 or 
02S1WR1 to identify the second series of amendments on tyre road rolling 
sound emissions at stage 1, tyre adhesion on wet surfaces and rolling 
resistance at stage 1 (see paragraph 6.1. below for stage 1 and stage 2 
definitions). No identification to the series of amendments shall be required if 
the relevant Regulation is in its original form. 
5.3.2. The following suffixes have been already reserved to identify specific 
Regulations on tyre performance parameters: 
S To identify additional conformity to the requirements on tyre rolling 
sound emissions; 
W To identify additional conformity to the requirements on tyre adhesion 
on wet surfaces; 
R To identify additional conformity to the requirements on tyre rolling 
resistance. 
 Taking into account that two stages are defined for rolling sound and rolling 
resistance specifications in paragraphs 6.1. and 6.3. below, S and R will be 
followed either by the suffix "1" for compliance to stage 1 or by the suffix 
"2" for compliance to stage 2. 
5.4. In the space referred to in paragraph 4.3. and in accordance with the 
requirements of paragraph 4.4. above there shall be affixed to every tyre size, 
conforming to the type of tyre approved under this Regulation, an 
international approval mark consisting of: 
5.4.1. A circle surrounding the letter "E" followed by the distinguishing number of 
the country which has granted approval;12 and 
  
 12 The distinguishing numbers of the Contracting Parties to the 1958 Agreement are reproduced in 
Annex 3 to the Consolidated Resolution on the Construction of Vehicles (R.E.3), document 
ECE/TRANS/WP.29/78/Rev. 4, Annex 3 - 
www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29resolutions.html  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 13 5.4.2. The approval number, which shall be placed close to the circle prescribed in 
paragraph 5.4.1. above either above or below the "E" or to the left or right of 
that letter. 
5.4.3. The suffix(es), and the identification to the relevant series of amendments, if 
any, as specified in the communication form. 
 One of the suffixes listed below or any combination of them can be used. 
S1 Sound level at stage 1  
S2 Sound level at stage 2  
W Wet adhesion level  
R1 Rolling resistance level at stage 1  
R2 Rolling resistance level at stage 2  
 These suffixes shall be placed to the right or below the approval number, if 
part of the original approval. 
 If the approval is extended subsequent to Regulation No. 30 or 54 approvals, 
the addition sign "+" and the series of amendment to Regulation No. 117 
shall be placed in front of the suffix or any combination of suffixes to denote 
an extension to the approval. 
 If the approval is extended subsequent to the original approval under 
Regulation No. 117, the addition sign "+" shall be placed between the suffix 
or any combination of suffixes of the original approval and the suffix or any 
combination of suffixes added to denote an extension to the approval. 
5.4.4. The marking on the tyre sidewalls of suffix(es) to the approval number 
removes the requirement for any additional marking on the tyre of the 
specific type approval number for conformity to the Regulation(s) to which 
the suffix refers as per paragraph 5.3.2. above. 
5.5. If the tyre conforms to type approvals under one or more other Regulation s 
annexed to the Agreement in the country which has granted approval under 
this Regulation, the symbol prescribed in paragraph 5.4.1. above need not be 
repeated. In such a case the additional numbers and symbols of all the 
Regulations under which approval has been granted in the country which has 
granted approval under this Regulation shall be placed adjacent to the symbol 
prescribed in paragraph 5.4.1. above. 
5.6. Annex 2 to this Regulation gives examples of arrangements of approval 
marks. 
  6.  Specifications 
6.1. Rolling sound emission limits, as measured by the method described in 
Annex 3 to this Regulation. 
6.1.1. For Class C1 tyres, the rolling sound emission value shall not exceed the 
values pertinent to the applicable stage given below. These values refer to the 
nominal section width as given in paragraph 2.17.1.1. of Regulation No. 30: E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
14 Stage 1  
Nominal section width Limit dB(A)  
145 and lower  72 
Over 145 up to 165  73 
Over 165 up to 185  74 
Over 185 up to 215  75 
Over 215  76 
The above limits shall be increased by 1 dB(A) for extra load tyres or reinf orced 
tyres and by 2  dB(A) for " special use tyres ". 
 
Stage 2  
Nominal section w idth Limit dB(A)  
185 and lower  70 
Over 185 up to 245  71 
Over 245 up to 275  72 
Over 275  74 
The above limits shall be increased by 1 dB(A) for "snow tyre  for use in severe 
snow conditions" , extra load tyres or reinforced tyres, or any combination of these 
classifications.  
6.1.2. For Class C2 tyres, the rolling sound emission value with reference to its 
category of use (see paragraph 2.1., subparagraph (d) above) shall not exceed 
the values pertinent to the applicable stage given below: 
Stage 1  
Category of use  Limit dB(A)  
Normal tyre  75 
Snow tyre  77 
Special use tyre  78 
 
Stage 2  
Category of use   Limit dB(A)  
Other  Traction tyres 
Normal tyre   72 73 
Snow tyre  72 73 
Snow tyre for use in 
severe snow conditions  73 75 
Special use tyre   74 75 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 15 6.1.3. For Class C3 tyres, the rolling sound emission value with reference to its 
category of use (see paragraph 2.1., subparagraph (d) above) shall not exceed 
the values pertinent to the applicable stage given below: 
Stage 1  
Category of use  Limit dB(A)  
Normal tyre  76 
Snow tyre  78 
Special use tyre  79 
 
Stage 2  
Category of use   Limit dB(A)  
Other  Traction tyres  
Normal tyre   73 75 
Snow tyre   73 75 
Snow tyre for use in severe 
snow conditions  74 76 
Special use tyre   75 77 
6.2. The wet grip performance will be based on a procedure that compares either 
peak brake force coefficient ("pbfc") or mean fully developed deceleration 
("mfdd") against values achieved by a standard reference test tyre (SRTT). 
The relative performance shall be indicated by a wet grip index (G). 
6.2.1. For Class C1 tyres, tested in accordance with either procedure given in 
Annex 5, Part (A), to this Regulation, the tyre shall meet the following 
requirements: 
Category of use   Wet grip index 
(G) 
Normal tyre  ≥  1.1  
Snow tyre  ≥  1.1  
"Snow tyre for use in severe snow 
conditions" and with a speed symbol 
("R" and above, including  "H") 
indicating a maximum permissible speed 
greater than  160 km/h  ≥  1.0  
"Snow tyre for use in severe snow 
conditions" and with a speed symbol 
("Q" or below excluding  "H") indicating 
a maximum permissible speed not 
greater than  160 km/h  ≥  0.9  
Special use tyre  Not defined  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
16 6.2.2. For Class C2 tyres, tested in accordance with either procedure given in 
Annex 5, Part (B), to this Regulation, the tyre shall meet the following 
requirements: 
Category of use   Wet grip index (G)  
Other  Traction tyres  
Normal tyre   ≥ 0.95  ≥ 0.85  
Snow tyre   ≥ 0.95  ≥ 0.85  
Snow tyre for use in severe 
snow conditions  ≥ 0.85  ≥ 0.85  
Special use tyre   ≥ 0.85  ≥ 0.85  
 
6.2.3.  For Class C3 tyres, tested in accordance with either procedure given in 
Annex 5, Part (B), to this Regulation, the tyre shall meet the following 
requirements: 
Category of use   Wet grip index (G)  
Other  Traction tyres  
Normal tyre   ≥ 0.80  ≥ 0.65  
Snow tyre   ≥ 0.65  ≥ 0.65  
Snow tyre for use in severe 
snow conditions  ≥ 0.65  ≥ 0.65  
Special use  tyre  ≥ 0.65  ≥ 0.65  
6.3. Rolling resistance coefficient limits, as measured by the method described in 
Annex 6 to this Regulation. 
6.3.1. The maximum values for stage 1 for the rolling resistance coefficient shall 
not exceed the following (value in N/kN is equivalent to value in kg/tonne): 
Tyre class  Max value (N/kN)  
C1 12.0 
C2 10.5 
C3 8.0 
For "snow tyre for use in severe snow conditions", the limits shall be 
increased by 1 N/kN.  
6.3.2. The maximum values for stage 2 for the rolling resistance coefficient shall 
not exceed the following (value in N/kN is equivalent to value in kg/tonne): 
Tyre class  Max value (N/kN)  
C1 10.5 
C2 9.0 
C3 6.5 
For "snow tyre for use in severe snow conditions”, the limits shall be 
increased by 1 N/kN.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 17 6.4. In order to be classified as a "snow tyre for use in severe snow conditions" the 
tyre shall meet the performance requirements of paragraph 6.4.1. below. The tyre 
shall meet these requirements based on a test method of Annex 7 by which: 
 (a) The mean fully developed deceleration ("mfdd") in a braking test, 
(b) Or alternatively an average traction force in a traction test, 
(c) Or alternatively the average acceleration in an acceleration test  
 of the candidate tyre is compared to that of a standard reference tyre. 
The relative performance shall be indicated by a snow index. 
6.4.1. Tyre snow performance requirements 
6.4.1.1. Class C1, C2 and C3 tyres 
 The minimum snow index value, as calculated in the procedure described in 
Annex 7 and compared with the SRTT shall be as follows: 
Class  
of tyre  Snow  grip index  
(brake on snow method) (a) Snow grip index  
(spin traction method) (b) Snow grip index  
(acceleration method) (c) 
 Ref. =  
C1 – SRTT 14  Ref. =  
C2 – SRTT 16C  Ref. =  
C1 – SRTT 14  Ref. = C3N – SRTT 19.5  
Ref. = C3W – SRTT 22.5  
C1  1.07 No 1.10 No 
C2 No 1.02 1.10 No 
C3 No No No 1.25 
  (a) See paragraph 3. of Annex 7 to this Regulation  
  (b) See paragraph 2. of Annex 7 to this Regulation 
  (c) See paragraph 4. of Annex 7 to this Regulation   
6.5. In order to be classified as a "traction tyre", a tyre is required to meet at least 
one of the conditions of paragraph 6.5.1. below. 
6.5.1. The tyre shall have a tread pattern with minimum two circumferential ribs, 
each containing a minimum of 30 block-like elements, separated by grooves 
and/or sipe elements the depth of which has to be minimum of one half of the 
tread depth. The use of an alternative option of a physical test will only apply 
at a later stage following a further amendment to the Regulation including a 
reference to an appropriate test methods and limit values. 
6.6. In order to be classified as a "special use tyre" a tyre shall have a block tread 
pattern in which the blocks are larger and more widely spaced than for 
normal tyres and have the following characteristics: 
For C1 tyres: a tread depth ≥ 11 mm and void to fill ratio ≥ 35 per cent  
For C2 tyres: a tread depth ≥ 11 mm and void to fill ratio ≥ 35 per cent  
For C3 tyres: a tread depth ≥ 16 mm and void to fill ratio ≥ 35 per cent  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
18 6.7. In order to be classified as a "professional off-road tyre ", a tyre shall have all 
of the following characteristics: 
 (a) For C1 and C2 tyres: 
  ( i) A tread depth ≥ 11 mm;  
  ( ii) A void- to-fill ratio ≥ 35 p er cent; 
  ( iii) A maximum speed rating of ≤ Q . 
 (b) For C3 tyres: 
  ( i) A tread depth ≥ 16 m m; 
  ( ii) A void- to-fill ratio ≥ 35 per cent ; 
  ( iii) A maximum speed rating of ≤ K . 
  7.  Modifications of the type of pneumatic tyre and 
  extension of approval 
7.1. Every modification of the type of tyre, which may influence the performance 
characteristics approved in accordance with this Regulation, shall be notified 
to the Type Approval Authority which approved the type of tyre. That 
Authority may either: 
7.1.1. Consider that the modifications are unlikely to have any appreciable adverse 
effect on the performance characteristics approved and that the tyre will 
comply with the requirements of this Regulation; or 
7.1.2. Require further samples to be submitted for test or further test reports from 
the designated Technical Service. 
7.1.3. Confirmation or refusal of approval, specifying the modifications, shall be 
communicated by the procedure given in paragraph 5.3. of this Regulation to 
the Parties to the Agreement which apply this Regulation. 
7.1.4. The Type Approval Authority granting the extension of approval shall assign 
a series number for such an extension which shall be shown on the 
communication form. 
  8.  Conformity of production 
 The conformity of production procedures shall comply with those set out in 
the Agreement, Appendix 2 (E/ECE/324-E/ECE/TRANS/505/Rev.2) with the 
following requirements: 
8.1. Any tyre approved under this Regulation shall be so manufactured as to 
conform to the performance characteristics of the type of tyre approved and 
satisfy the requirements of paragraph 6. above; 
8.2. In order to verify conformity as prescribed in paragraph 8.1. above, a random 
sample of tyres bearing the approval mark required by this Regulation shall 
be taken from the series production. The normal frequency of verification of 
conformity of production shall be at least once every two years; E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 19 8.2.1. In the case of verifications with regard to approvals in accordance with 
paragraph 6.2. of this Regulation, these shall be carried out using the same 
procedure (see Annex 5 to this Regulation) as that adopted for original 
approval, and the Type Approval Authority shall satisfy itself that all tyres 
falling within an approved type comply with the approval requirement. The 
assessment shall be based upon the production volume of the tyre type at 
each manufacturing facility, taking into account the quality management 
system(s) operated by the manufacturer. Where the test procedure involves 
testing a number of tyres at the same time, for example a set of four tyres for 
the purpose of testing wet grip performance in accordance with the standard 
vehicle procedure given in Annex 5 to this Regulation, then the set shall be 
considered as being one unit for the purposes of calculating the number of 
tyres to be tested. 
8.3. Production shall be deemed to conform to the requirements of this Regulation 
if the levels measured comply with the limits prescribed in paragraph 6.1. of 
this Regulation, with an additional allowance of +1 dB(A) for possible mass 
production variations. 
8.4. Production shall be deemed to conform to the requirements of this Regulation 
if the levels measured comply with the limits prescribed in paragraph 6.3. of 
this Regulation, with an additional allowance of +0.3 N/kN for possible mass 
production variations. 
  9.  Penalties for non-conformity of production 
9.1. The approval granted in respect of a type of tyre pursuant to this Regulation 
may be withdrawn if the requirements laid down in paragraph 8. above are 
not complied with, or if any tyre of the type of tyre exceeds the limits given 
in paragraph 8.3. or 8.4. above. 
9.2. If a Party to the Agreement, which applies this Regulation, withdraws an 
approval, it has previously granted, it shall forthwith notify the other 
Contracting Parties applying this Regulation by means of a copy of the 
approval form conforming to the model in Annex 1 to this Regulation. 
  10.  Production definit ively discontinued 
 If the holder of an approval completely ceases to manufacture a type of 
pneumatic tyre approved in accordance with this Regulation, he shall so 
inform the Type Approval Authority, which granted the approval. Upon 
receiving the relevant communication that Authority shall inform thereof 
the other Parties to the 1958 Agreement applying this Regulation by means 
of a communication form conforming to the model in Annex 1 to this 
Regulation. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
20   11.  Names and addresses of Technical Services  
  responsible for conducting approval tests of Type 
  Approval Authorities  
 The Parties to the Agreement which apply this Regulation shall communicate 
to the United Nations Secretariat, the names and addresses of the Technical 
Services conducting approval tests and of the Type Approval Authority 
which grant approval and to which forms certifying approval or extension of 
approval or refusal or withdrawal of approval, issued in other countries, are 
to be sent. 
  12.  Transitional provisions 
12.1. As from the date of entry into force of the 02 series of amendments to this 
Regulation, Contracting Parties applying this Regulation shall not refuse to 
grant approval under this Regulation for a type of tyre if the tyre complies 
with the requirements of the 02 series of amendments, including the stage 1 
or stage 2 rolling sound requirements set out in paragraphs 6.1.1. to 6.1.3. of 
this Regulation, the requirements for wet grip performance set out in 
paragraph 6.2. 1. of this Regulation, and the stage 1 or stage 2 rolling 
resistance requirements set out in paragraph 6.3.1. or 6.3.2. of this 
Regulation. 
12.2. As from 1 November 2012, Contracting Parties applying this Regulation 
shall refuse to grant approval if the tyre type to be approved does not meet 
the requirements of this Regulation as amended by the 02 series of 
amendments, and shall, in addition, refuse to grant approval if the stage 2 
rolling sound requirements set out in paragraphs 6.1.1. to 6.1.3. of this 
Regulation , the requirements for wet grip performance set out in 
paragraph 6.2. 1. of this Regulation, and the stage 1 rolling resistance 
requirements set out in paragraph 6.3.1. of this Regulation are not complied 
with. 
12.3. As from 1 November 2014, Contracting Parties applying this Regulation may 
refuse to allow the sale or entry into service of a tyre which does not meet the 
requirements of this Regulation as amended by the 02 series, and which does 
not meet the requirements of this Regulation as amended by the 02 series of 
amendments including the wet grip performance requirements set out in 
paragraph 6.2. 1. of this Regulation. 
12.4. As from 1 November 2016, Contracting Parties applying this Regulation 
shall refuse to grant approvals if the tyre type to be approved does not meet 
the requirements of this Regulation as amended by the 02 series of 
amendments including the stage 2 rolling resistance requirements set out in 
paragraph 6.3.2. of this Regulation and the wet grip requirements set out in 
paragraphs 6.2.2. and 6.2.3. of this Regulation. 
12.5. As from 1 November 2016, any Contracting Party applying this Regulation 
may refuse to allow the sale or entry into service of a tyre which does no t 
meet the requirements of this Regulation as amended by the 02 series, and 
which does not meet the stage 2 rolling sound requirements set out in 
paragraphs 6.1.1. to 6.1.3. of this Regulation. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
 
 21 12.6. As from the dates given below, any Contracting Party applying this 
Regulation may refuse to allow the sale or entry into service of a tyre which 
does not meet the requirements of this Regulation as amended by the 
02 series, and which does not meet the stage 1 rolling resistance requirements 
set out in paragraph 6.3.1. of this Regulation: 
Tyre class  Date  
C1, C2  1 November 2014  
C3 1 November 2016  
12.7. As from the dates given below, any Contracting Party applying this 
Regulation may refuse to allow the sale or entry into service of a tyre which 
does not meet the requirements of this Regulation as amended by the 
02 series, and which does not meet the stage 2 rolling resistance requirements 
set out in paragraph 6.3.2. of this Regulation and the wet grip requirements 
set out in paragraphs 6.2.2. and 6.2.3. of this Regulation: 
Tyre class  Date  
C1 and C2  1 November 2018  
C3 1 November 2020  
12.8. Until 13 February 2019 (60 months after the entry into force of Supplement 4 
to the 02 series of amendments to this Regulation) Contracting Parties 
applying this Regulation may continue to grant type approvals according to 
the 02 series of amendments to this Regulation, based on the provisions of 
Annex 4 to this Regulation. 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annexe 1 
 
22  Annex 1 
  Communication 
(Maximum format: A4 (210 x 297 mm)) 
 Issued by:  Name of administration:  
......................................  
......................................  
......................................  
111 
Concerning:2  Approval granted 
   Approval extended 
   Approval refused 
   Approval withdrawn 
   Production definitively discontinued 
of a type of tyre with regard to "rolling sound emission level" and/or "adhesion 
performance on wet surfaces" and/or "rolling resistance" pursuant to Regulation No. 117 
Approval No. ....... ........................................  Extension No.  ...............................   
1. Manufacturer's name and address(es):  .........................................................................   
2. If applicable, name and address of manufacturer's representative:  ..............................   
3. "Tyre class" and "category of use" of the type of tyre:  ................................................   
3.1. Snow tyre for use in severe snow conditions (Yes/No)2 
3.2. Traction tyre (Yes/No)2 
4. Brand(s) name(s) and/or Trade description(s) of the type of tyre:  ...............................   
5. Technical Service and, where appropriate, test laboratory approved for purposes of 
approval or of verification of conformity tests: ............................................................   
6. Performance(s) approved: sound level at (stage 1/stage 2),2 wet adhesion level, 
 rolling resistance level (stage 1/stage 2)2 
6.1. Sound level of the representative tyre size, see paragraph 2.5. of this Regulation, as 
per item 7. of the test report in Appendix 1 to Annex 3: ................ dB(A) a t 
reference speed of 70/80 km/h2 
6.2. Wet adhesion level of the representative tyre size, see paragraph 2.5. of this 
Regulation, as per item 7. of the test report in the appendix to Annex 5: 
……………………… (G) using t he vehicle or trailer method2 
  
 1 Distinguishing number of the country which has granted/extended/refused/withdrawn approval 
(see approval provisions in the Regulation). 
 2 Strike out what does not apply. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 1 
 
 23 6.3. Rolling resistance level of the representative tyre size, see paragraph 2.5. of this 
Regulation, as per item 7. of the test report in Appendix 1 to Annex 6 ........................   
6.4. Snow grip level of the representative tyre size, see paragraph 2.5. of Regulation No. 
117, as per item 7. of the test report in the appendix3 to Annex 7:………………. 
(Snow grip index) using the brake on snow method2, spin traction method2 or 
acceleration method.2 
7. Number of report issued by the Technical Service :  .....................................................   
8. Date of report issued by that Service :  ..........................................................................   
9. Reason(s) of extension (if applicable): .........................................................................   
10. Any remarks: .................................................................................................................   
11. Place:  ............................................................................................................................   
12. Date:  .............................................................................................................................   
13. Signature:  .....................................................................................................................   
14. Annexed to this communication are:  ............................................................................   
14.1. A list of documents in the approval file deposited at the Type Approval Authorities 
having delivered the approval and which can be obtained upon request. 4 
14.2. A list of tread-pattern designations: Specify for each trademark or brand name and 
trade description the list of tyre size designations, adding in case of Class C1 tyres 
the mark "reinforced" (or "extra load") or the speed symbol of snow tyres or in the 
case of tyres of Classes C2 and C3, the mark "traction", if so required by 
paragraph 3.1. of this Regulation. 
  
 3 Appendix 2 for C1 and C2 tyres. 
  Appendix 3 for C3 tyres.  
 4 In the case of "snow tyre for use in severe snow conditions" a test report according to Appendix 2 to 
Annex 7 shall be submitted. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annexe 2 - Appendix 1 
 
24  Annex 2 - Appendix 1 
  Example of approval marks 
Arrangements of approval marks 
(See paragraph 5.4. of this Regulation) 
Approval according to Regulation No. 117 
Example 1 
 
 
The above approval mark, affixed to a pneumatic tyre shows that a tyre concerned 
has been approved in the Netherlands (E 4) pursuant to Regulation No. 117 (marked by S2 
(rolling sound at stage 2) only), under approval number 0212345. The first two digits of the 
approval number (02) indicate that the approval was granted according to the requirements 
02 series of amendments to this Regulation. 
Example 2 
 
 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E 4) pursuant to Regulation No. 117 (marked by S1 (rolling sound at stage 1) 
W (wet adhesion), and R1 ( Rolling resistance at stage 1 ) under approval number 0212345. 
This indicates that the approval is for S1WR1. The first two digits of the approval number 
(02) indicate that the approval was granted according to the requirements of the 02 series of 
amendments to this Regulation. 
 0212345 S2  
0212345 S1WR1  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 2 - Appendix 2 
 
 25 Annex 2 - Appendix 2 
  Approval according to Regulation No. 117 coincident with 
approval of Regulation No. 30 or 541 
Example 1 
 
     a/3     0212345 S2 0236378  
 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E 4) pursuant to Regulation No. 117 (marked by S2 (rolling sound at 
stage 2)), under approval number 0212345 and Regulation No. 30, under approval 
number 0236378. The first two digits of the approval number (02) indicate that the approval 
was granted according to the 02 series of amendments and Regulation No. 30 included the 
02 series of amendments. 
  
 1 Approvals in accordance with Regulation No. 117 for tyres within the scope of Regulation No. 54 
currently do not include wet adhesion requirements. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annexe 2 - Appendix 2 
 
26  Example 2 
 
a/3     0212345 S2 0236378  
 
 
 
 
 
 
 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E 4) pursuant to Regulation No. 117 (marked by S2WR2 (rolling sound at 
stage 2 wet adhesion and rolling resistance at stage 2)), under approval number 0212345 
and Regulation No. 30 under approval number 0236378. The first two digits of the approval 
number (02) indicate that the approval was granted according to the 02 series of 
amendments and Regulation No. 30 included the 02 series of amendments. 
Example 3 
 
a/3     0212345 S2 0054321  
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E 4) pursuant to Regulation No. 117 and the 02 series of amendments under 
approval number 0212345 (marked by S2), and Regulation No. 54. This indicates that the 
approval is for rolling sound stage 2 (S2). The first two digits of the Regulation No. 117 
approval number (02) in conjunction with "S2" indicate that the first approval was granted 
in accordance with Regulation No. 117 which included the 02 series of amendments. The 
first two digits of Regulation No. 54 (00) indicate that this Regulation was in its original 
form. 
  or  
 
 0212345 S2WR2  
0236378   
   
 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 2 - Appendix 2 
 
 27 Example 4 
 
 
a/3     0212345 S2 0054321 
The above approval mark shows that the tyre concerned has been approved in the 
Netherlands (E 4) pursuant to Regulation No. 117 and the 02 series of amendments under 
approval number 0212345 (marked by S2 R2), and Regulation No. 54. This indicates that 
the approval is for rolling sound stage 2 (S2) and rolling resistance stage 2. The first two 
digits of the Regulation No. 117 approval number (02) in conjunction with "S2R2" indicate 
that the first approval was granted in accordance with Regulation No. 117 which included 
the 02 series of amendments. The first two digits of Regulation No. 54 (00) indicate that 
this Regulation was in its original form. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 2 - Appendix 3 
 
28  Annex 2 - Appendix 3 
  Extensions to combine approvals issued in accordance with 
Regulation s Nos. 117, 30 or 541 
Example 1 
 
a/3     0236378 + 02S1  
 
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E 4) pursuant to Regulation No. 30 and the 02 series of amendments 
under approval number 0236378. It is also marked by + 02S1 (rolling sound at stage 1) 
which indicates that its approval is extended under Regulation No. 117 (02 series of 
amendments). The first two digits of the approval number (02) indicate that the approval 
was granted according to Regulation No. 30 (02 series of amendments). The addition (+) 
sign indicates that the first approval was granted in accordance with Regulation No. 30 and 
has been extended to include the approval(s) granted according to Regulation No. 117 (02 
series of amendments) for rolling sound at stage 1. 
Example 2 
 
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E 4) pursuant to Regulation No. 30 and the 02 series of amendments 
under approval number 0236378. This indicates that the approval is for S1 (rolling sound at 
stage 1) W (wet adhesion) and R2 (rolling resistance at stage 2). The S1WR2 preceded by 
(02) indicates that it has had its approval extended under Regulation No. 117 which 
included the 02 series of amendments. The first two digits of the approval number (02) 
indicate that the approval was granted according to Regulation No. 30 (02 series of 
amendments). The addition (+) sign indicates that the first approval was granted in 
accordance with Regulation No. 30 and has been extended to include Regulation No. 117 
approval(s) (02 series of amendments). 
  
 1 Approvals in accordance with Regulation No. 117 for tyres within the scope of Regulation No. 54 
currently do not include wet adhesion requirements. 
 0236378 + 02S1WR2   
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 2 - Appendix 4 
 
 29 Annex 2 - Appendix 4 
  Extensions to combine approvals issued in accordance with 
Regulation No. 1171 
Example 1 
 
 
 
 
 
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E 4) pursuant to Regulation No. 117 and the 02 series of amendments 
under approval number 0212345. This indicates that the approval is for W (wet grip). The 
S2R2 preceded by + indicates that it has had its approval extended under Regulation 
No. 117 to rolling sound at stage 2 and rolling resistance at stage 2 based on separate 
certificate(s). 
Example 2 
 
 
 
 
 
 
 
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E 4) pursuant to Regulation No. 117 and the 02 series of amendments 
under approval number 0212345. This indicates that the approval is for S1 (rolling sound at 
stage 1) and W (wet grip). The R1 preceded by + indicates that it has had its approval 
extended under Regulation No. 117 to rolling resistance at stage 1 based on separate 
certificate(s). 
  
 1 Approvals in accordance with Regulation No. 117 for tyres within the scope of Regulation No. 54 
currently do not include wet adhesion requirements.   
 
 
 0212345 W + S2R2   
 a ≥ 12 mm  
 0212345 S1W + R1   E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 2 - Appendix 4 
 
30  Example 3 
 
 
 
 
The above approval mark shows that the tyre concerned has been initially approved 
in the Netherlands (E 4) pursuant to Regulation No. 117 and the 01 series of amendments 
under approval number 0167890. This indicates that the approval is for S (rolling sound at 
stage 1) and W (wet grip). The 02R1 preceded by + indicates that it has had its approval 
extended under Regulation No. 117 and the 02 series of amendments to rolling resistance at 
stage 1 based on separate certificate(s).   
 0167890 SW + 02R1   E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
 31 Annex 3 
  Coast-by test method for measuring tyre-rolling sound 
emission 
 Introduction 
The presented method contains specifications on measuring instruments , 
measurement conditions  and the measurement method, in order to obtain the 
sound level of a set of tyres mounted on a test vehicle rolling on a specified 
road surface. The maximum sound pressure level is to be recorded, when the 
test vehicle is coasting, by remote-field microphones; the final result for a 
reference speed is obtained from a linear regression analysis. Such test results 
cannot be related to tyre rolling sound measured during acceleration under 
power or deceleration under braking. 
1. Measuring instruments 
1.1. Acoustic measurements 
The sound level meter or the equivalent measuring system, including the 
windscreen recommended by the manufacturer shall meet or exceed the 
requirements of Type 1 instruments in accordance with 
IEC 60651:1979/A1:1993, second edition. 
The measurements shall be made using the frequency weighting A, and the 
time weighting F. 
When using a system that includes a periodic monitoring of the A-weighted 
sound level, a reading should be made at a time interval not greater than 30 ms. 
1.1.1. Calibration 
 At the beginning and at the end of every measurement session, the entire 
measurement system shall be checked by means of a sound calibrator that 
fulfils the requirements for sound calibrators of at least precision Class 1 
according to IEC 60942:1988. Without any further adjustment the difference 
between the readings of two consecutive checks shall be less than or equal to 
0.5 dB(A). If this value is exceeded, the results of the measurements obtained 
after the previous satisfactory check shall be discarded. 
1.1.2. Compliance with requirements 
 The compliance of the sound calibration device with the requirements of 
IEC 60942:1988 shall be verified once a year and the compliance of the 
instrumentation system with the requirements of IEC 60651:1979/A1:1993, 
second edition shall be verified at least every two years, by a laboratory 
which is authorized to perform calibrations traceable to the appropriate 
standards. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
32  1.1.3. Positioning of the microphone 
The microphone (or microphones) shall be located at a distance of 
7.5 ± 0.05 m from track reference line CC' (Figure 1) and 1.2 ± 0.02 m above 
the ground. Its axis of maximum sensitivity shall be horizontal and 
perpendicular to the path of the vehicle (line CC'). 
1.2. Speed measuremen ts 
 The vehicle speed shall be measured with instruments with accuracy 
of ±1 km/h or better when the front end of the vehicle has reached line PP 
(Figure 1). 
1.3. Temperature measurements 
 Measurements of air as well as test surface temperature are mandatory. 
 The temperature measuring devices shall be accurate within ±1 °C. 
1.3.1. Air temperature 
 The temperature sensor is to be positioned in an unobstructed location close 
to the microphone in such a way that it is exposed to the airflow and 
protected from direct solar radiation. The latter may be achieved by any 
shading screen or similar device. The sensor should be positioned at a height 
of 1.2 ± 0.1 m above the test surface level, to minimize the influence of the 
test surface thermal radiation at low airflows. 
1.3.2. Test surface temperature 
 The temperature sensor is to be positioned in a location where the 
temperature measured is representative of the temperature in the wheel 
tracks, without interfering with the sound measurement. 
 If an instrument with a contact temperature sensor is used, heat-conductive 
paste shall be applied between the surface and the sensor to ensure adequate 
thermal contact. 
 If a radiation thermometer (pyrometer) is used, the height should be chosen 
to ensure that a measuring spo t with a diameter of ≥  0.1 m is covered. 
1.4. Wind measurement 
 The device shall be capable of measuring the wind speed with a tolerance of 
±1 m/s. The wind shall be measured at microphone height. The wind 
direction with reference to the driving direction shall be recorded. 
2. Conditions of measurement 
2.1. Test site 
 The test site shall consist of a central section surrounded by a substantially 
flat test area. The measuring section shall be level; the test surface shall be 
dry and clean for all measurements. The test surface shall not be artificially 
cooled during or prior the testing. 
The test track shall be such that the conditions of a free sound field between 
the sound source and the microphone are attained to within 1 dB(A). These 
conditions shall be deemed to be met if there is no large sound reflecting 
objects, such as fences, rocks, bridges or building within 50 m of the centre 
of the measuring section. The surface of the test track and the dimensions of E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
 33 the test site shall be in accordance with ISO 10844:2014. Until the end of the 
period indicated in paragraph 12.8. of this Regulation the specifications for 
the test site may be in accordance with Annex 4 to this Regulation. 
A central part of at least 10 m radius shall be free of powdery snow, tall grass, 
loose soil, cinders or the like. There shall be no obstacle, which could affect the 
sound field within the vicinity of the microphone and no persons shall stand 
between the microphone and the sound source. The operator carrying out the 
measurements and any observers attending the measurements shall position 
themselves so as not to affect the readings of the measuring instruments. 
2.2. Meteorological conditions 
 Measurements shall not be made under poor atmospheric conditions. It shall 
be ensured that the results are not affected by gusts of wind. Testing shall not 
be performed if the wind speed at the microphone height exceeds 5 m/s. 
 Measurements shall not be made if the air temperature is below 5 °C or above 
40 °C or the test surface temperature is below 5 °C or above 50 °C. 
2.3. Ambient noise 
2.3.1. The background sound level (including any wind noise) shall be at least 
10 dB(A) less than the measured tyre rolling sound emission. A suitable 
windscreen may be fitted to the microphone provided that account is taken of 
its effect on the sensitivity and directional characteristics of the microphone. 
2.3.2. Any measurement affected by a sound peak which appears to be unrelated to 
the characteristics of the general sound level of tyres, shall be ignored. 
2.4. Test vehicle requirements 
2.4.1. General 
 The test vehicle shall be a motor vehicle and be fitted with four single tyres 
on just two axles. 
2.4.2. Vehicle load 
 The vehicle shall be loaded such as to comply with the test tyre loads as 
specified in paragraph 2.5.2. below. 
2.4.3. Wheelbase  
 The wheelbase between the two axles fitted with the test tyres shall for Class C1 
be less than 3.50 m and for Class C2 and Class C3 tyres be less than 5 m. 
2.4.4. Measures to minimize vehicle influence on sound level measurements 
 To ensure that tyre rolling sound is not significantly affected by the  test 
vehicle design the following requirements and recommendations are given. 
2.4.4.1. Requirements: 
(a) Spray suppression flaps or other extra device to suppress spray shall 
not be fitted; 
(b) Addition or retention of elements in the immediate vicinity of the rims 
and tyres, which may screen the emitted sound, is not permitted; 
(c) Wheel alignment (toe in, camber and caster) shall be in full 
accordance with the vehicle manufacturer's recommendations; E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
34  (d) Additional sound absorbing material may not be mounted in the wheel 
housings or under the underbody; 
(e) Suspension shall be in such a condition that it does not result in an 
abnormal reduction in ground clearance when the vehicle is loaded in 
accordance with the testing requirement. If available, body level 
Regulation systems shall be adjusted to give a ground clearance 
during testing which is normal for unladen condition. 
2.4.4.2. Recommendations to avoid parasitic noise: 
(a) Removal or modification on the vehicle that may contribute to the 
background noise of the vehicle is recommended. Any removals or 
modifications shall be recorded in the test report; 
(b) During testing it should be ascertained that brakes are not poorly 
released, causing brake noise; 
(c) It should be ascertained that electric cooling fans are not operating; 
(d) Windows and sliding roof of the vehicle shall be closed during testing. 
2.5. Tyres 
2.5.1. General 
 Four identical  tyres shall be fitted on the test vehicle. In the case of tyres with a 
load capacity index in excess of 121 and without any dual fitting indication, two 
of these tyres of the same type and range shall be fitted to the rear axle of the test 
vehicle; the front axle shall be fitted with tyres of size suitable for the axle load 
and planed down to the minimum depth in order to minimize the influence of 
tyre/road contact noise while maintaining a sufficient level of safety. Winter tyres 
that in certain Contracting Parties may be equipped with studs intended to 
enhance friction shall be tested without this equipment. Tyres with special fitting 
requirements shall be tested in accordance with these requirements (e.g. rotation 
direction). The tyres shall have full tread depth before being run-in. 
Tyres are to be tested on rims permitted by the tyre manufacturer. 
2.5.2.  Tyre loa ds 
 The test load Q t for each tyre on the test vehicle shall be 50 to 90 per cent of 
the reference load Q r, but the average test load Q t,avr of all tyres shall be 
75 ± 5 per cent of the reference load Q r. 
 For all tyres the reference load Q r corresponds to the maximum mass 
associated with the load capacity index of the tyre. In the case where the load 
capacity index is constituted by two numbers divided by slash (/), reference 
shall be made to the first number. 
2.5.3.  Tyre inflation pressure 
 Each tyre fitted on the test vehicle shall have a test pressure P t not higher than 
the reference pressure P r and within the interval: 
25. 1
rt
r t25. 1
rt
rQQP 1 . 1 PQQP


  



 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
 35 For Class C2 and Class C3 the reference pressure P r is the pressure 
corresponding to the pressure index marked on the sidewall. 
 For Class C1 the reference pressure is P r = 250 kPa for "standard" tyres 
and 290 kPa for "reinforced" or "extra load" tyres; the minimum test pressure 
shall be P t = 150 kPa. 
2.5.4.  Preparations prior to testing 
 The tyres shall be "run-in" prior to testing to remove compound nodules or 
other tyre pattern characteristics resulting from the moulding process. This 
will normally require the equivalent of about 100 km of normal use on the 
road. 
 The tyres fitted to the test vehicle  shall rotate in the same direction as when 
they were run-in. 
 Prior to testing tyres shall be warmed up by running under test conditions. 
3. Method of testing 
3.1. General conditions 
 For all measurements the vehicle shall be driven in a straight line over the 
measuring section (AA' to BB') in such a way that the median longitudinal 
plane of the vehicle is as close as possible to the line CC'. 
 When the front end of the test vehicle has reached the line AA' the vehicle 
driver shall have put the gear selector on neutral position and switched off the 
engine. If abnormal noise (e.g. ventilator, self-ignition) is emitted by the test 
vehicle during the measurement, the test shall be disregarded. 
3.2. Nature and number of measurements 
 The maximum sound level expressed in A-weighted decibels (dB(A)) shall 
be measured to the first decimal place as the vehicle is coasting between lines 
AA' and BB' (Figure 1 - front end of the vehicle on line AA', rear end of the 
vehicle on line BB'). This  value will constitute the result of the measurement. 
 At least four measurements shall be made on each side of the test vehicle at 
test speeds lower than the reference speed specified in paragraph 4.1. below 
and at least four measurements at test speeds higher than the reference speed. 
The speeds shall be approximately equally spaced over the speed range 
specified in paragraph 3.3. below. 
3.3. Test speed range 
 The test vehicle speeds shall be within the range: 
 (a) From 70 to 90 km/h for Class C1 and Class C2 tyres; 
 (b) From 60 to 80 km/h for Class C3 tyres. 
4. Interpretation of results 
 The measurement shall be invalid if an abnormal discrepancy between the 
values is recorded (see paragraph 2.3.2. of this annex). E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
36  4.1. Determination of test result 
 Reference speed V ref used to determine the final result will be: 
 (a) 80 km/h for  Class C1 and Class C2 tyres; 
 (b) 70 km/h for  Class C3 tyres. 
4.2. Regression analysis of rolling sound measurements 
 The tyre-road rolling sound level L R in dB(A) is determined by a regression 
analysis according t o: 
 
Where:  
  is the mean value of the rolling sound levels L i, measured 
in db(A):  
  

n
1 ii_
Ln1L
 
n  is the measurement number (n ≥ 16),  
  is the mean value of logarithms of speeds V i: 
  
 
a  is the slope of the regression line in dB(A):  
  
aL Li i
in
i
in 


()()
( ) 
 1
2
1
 
4.3. Temperature correction 
 For Class C1 and Class C2 tyres, the final result shall be normalized to a test 
surface reference temperature ref by applying a temperature correction, 
according to the following: 
LR(ref) = L R() + K(ref - ) 
Where:  
 = the measured test surface temperature,  
ref = 20 °C,  
 For Class C1 tyres, the coefficient K is: -0.03 db(A)/°C, when  > ref  
 and -0.06 dB(A)/°C when  < ref. 
 For Class C2 tyres, the coefficient K is -0.02 dB(A)/°C   
               
      1   
1   n   with    V   V   
i   
i   n   
i   ref       
i   lg(   /   )    L     a L L 
R E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 
 
 37  If the measured test surface temperature does not change more than 5 °C 
within all measurements necessary for the determination of the sound level of 
one set of tyres, the temperature correction may be made only on the final 
reported tyre rolling sound level as indicated above, utilizing the arithmetic 
mean value of the measured temperatures. Otherwise each measured sound 
level L i shall be corrected, utilizing the temperature at the time of the sound 
recording. 
 There will be no temperature correction for Class C3 tyres. 
4.4. In order to take account of any measuring instrument inaccuracies, the results  
according to paragraph 4.3. above shall be reduced by 1 dB(A). 
4.5. The final result, the temperature corrected tyre rolling sound level L R(ref) in 
dB(A), shall be rounded down to the nearest lower whole value. 
Figure 1 
Microphone positions for the measurement 
 
 
 
 
 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 - Appendix 1 
 
38  Annex 3 - Appendix 1 
  Test report 
Part 1 - Report 
1. Type Approval Authority or Technical Service:  ..........................................................   
2. Name and address of applicant:  ...................................................................................   
  ......................................................................................................................................  
3. Test report No.:  ............................................................................................................   
4. Manufacturer and Brand Name or Trade description:  ..................................................   
5. Tyre Class (C1, C2 or C3):  ..........................................................................................   
6. Category of use:  ...........................................................................................................   
7. Sound level according to paragraphs 4.4. and 4.5. of Annex 3:  .......................  dB(A) 
 at reference speed of 70/80 km/h1  
8. Comments (if any):  ......................................................................................................  
  ......................................................................................................................................  
9. Date:  .............................................................................................................................   
10. Signature:  .....................................................................................................................   
Part 2 - Test data 
1. Date of test:  ..................................................................................................................   
2. Test vehicle (Make, model, year, modifications, etc.):  ................................................   
  ......................................................................................................................................  
2.1. Test vehicle wheelbase:  .......................................................................................  mm 
3. Location of test track:  ..................................................................................................  
3.1. Date of track certification to ISO 10844: 2014 :  ............................................................   
3.2. Issued by:  .....................................................................................................................   
3.3. Method of certification:  ...............................................................................................   
4. Tyre test details:  ...........................................................................................................   
4.1. Tyre size designation:  ..................................................................................................  
4.2. Tyre service description:  ..............................................................................................   
4.3. Reference inflation pressure: ................................................................................  kPa 
  
 1 Strike out what does not apply. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 3 - Appendix 1 
 
 39 4.4. Test data:  ......................................................................................................................   
 Front left  Front right  Rear left  Rear right  
Test mass (kg)      
Tyre load index (%)      
Inflation pressure (cold) 
(kPa)      
4.5. Test rim width code:  ....................................................................................................  
4.6. Temperature measurement sensor type:  .......................................................................  
5. Valid test results:  ..........................................................................................................   
Run 
No. Test 
speed  
km/h  Direction 
of run  Sound level  left1 
measured  dB(A)  Sound level  
right1 
measured  
dB(A)  Air temp.   
oC Track  temp.  
oC Sound level  left1 
temp. corrected  
dB(A)  Sound level  right1 
temp. corrected  
dB(A)  Comments  
1          
2          
3          
4          
5          
6          
7          
8          
1  Relative to the vehicle.  
5.1. Regression line slope:  ..................................................................................................  
5.2. Sound level after temperature correction according to paragraph 4.3. of Annex 3: 
  .......................................................................................................................... dB(A) 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
40  Annex 4 
  Specifications for the test site1 
1. Introduction 
 This annex describes the specifications relating to the physical characteristics 
and the laying of the test track. These specifications based on a special 
standard2 describe the required physical characteristics as well as the test 
methods for these characteristics. 
2. Required characteristics of the surface 
 A surface is considered to conform to this standard provided that the texture 
and voids content or sound absorption coefficient have been measured and 
found to fulfil all the requirements of paragraphs 2.1. to 2.4. below and 
provided that the design requirements (paragraph 3.2. below) have been met. 
2.1. Residual voids content 
 The residual Voids Content (VC) of the test track paving mixture shall not 
exceed 8 per cent. For the measurement procedure, see paragraph 4.1. of this 
annex. 
2.2. Sound absorption coefficient 
 If the surface fails to comply with the residual voids content requirement, the 
surface is acceptable only if its sound absorption coefficient is α ≤ 0.10. For 
the measurement procedure, see paragraph 4.2. below. The requirements of 
this paragraph 2.1. above are met also if only sound absorption has been 
measured and found to be α  ≤ 0.10. 
 Note : The most relevant characteristic is the sound absorption, although the 
residual voids content is more familiar among road constructors. However, 
sound absorption needs to be measured only if the surface fails to comply 
with the voids requirement. This is motivated because the latter is connected 
with relatively large uncertainties in terms of both measurements and 
relevance and some surfaces therefore erroneously may be rejected when 
based only on the voids measurement. 
2.3. Texture depth 
 The Texture Depth (TD) measured according to the volumetric method (see 
paragraph 4.3. below) shall be: 
TD ≥ 0.4 mm  
  
 1 The specifications for the test site reproduced in this annex are valid until the end of the period 
indicated in paragraph 12.8. of this Regulation. 
 2 ISO 10844:2014. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
 41 2.4. Homogeneity of the surface 
 Every practical effort shall be taken to ensure that the surface is made to be as 
homogeneous as possible within the test area. This includes the texture and 
voids content, but it should also be observed that if the rolling process results 
in more effective rolling at some places than others, the texture may be 
different and unevenness causing bumps may also occur. 
2.5. Period of testing 
 In order to check whether the surface continues to conform to the texture and 
voids content or sound absorption requirements stipulated in this standard, 
periodic testing of the surface shall be done at the following intervals: 
 (a) For residual VC or sound absorption (α):  
  When the surface is new: 
 If the surface meets the requirements when new, no further periodical 
testing is required. If it does not meet the requirement when it is new, 
it may do so later because surfaces tend to become clogged and 
compacted with time; 
 (b) For TD: 
 When the surface is new: 
 When the noise testing starts ( Note : Not before four weeks after 
laying); 
 Then every twelve months. 
3. Test surface design 
3.1. Area 
 When designing the test track layout it is important to ensure that, as a 
minimum requirement, the area traversed by the vehicles running through the 
test strip is covered with the specified test material with suitable margins for 
safe and practical driving. This will require that the width of the track is at 
least 3 m and the length of the track extends beyond lines AA and BB by at 
least 10 m at either end. Figure 1 shows a plan of a suitable test site and 
indicates the minimum area which shall be machine laid and machine 
compacted with the specified test surface material. According to Annex 3, 
paragraph 3.2., measurements have to be made on each side of the vehicle. 
This can be made either by measuring with two microphone locations (one on 
each side of the track) and driving in one direction, or measuring with a 
microphone only on one side of the track but driving the vehicle in two 
directions. If the latter method is used, then there are no surface requirements 
on that side of the track where there is no microphone. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
42  Figure 1 
Minimum requirements for test surface area. The shaded part is called "Test area" 
 
3.2. Design and preparation of the surface 
3.2.1. Basic design requirements 
 The test surface shall meet four design requirements: 
3.2.1.1. It shall be a dense asphaltic concrete. 
3.2.1.2. The maximum chipping size shall be 8 mm (tolerances allow from 6.3 mm 
to 10 mm). 
3.2.1.3. The thickness of the wearing course shall be ≥ 30  mm. 
3.2.1.4. The binder shall be a straight penetration grade bitumen without 
modification. 
3.2.2. Design guidelines 
 As a guide to the surface constructor, an aggregate grading curve which will 
give desired characteristics is shown in Figure 2. In addition, Table 1 gives 
some guidelines in order to obtain the desired texture and durability. The 
grading curve fits the following formula: 
P (% passing) = 100 · (d/d max) 1/2 
Where:  
d = square mesh sieve size, in mm  
dmax = 8 mm for the mean curve  
 = 10 mm for the lower tolerance curve  
 = 6.3 mm for the upper tolerance curve  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
 43 Figure 2 
Grading curve of the aggregate in the asphaltic mix with tolerances 
 
 
 In addition to the above, the following recommendations are given: 
(a) The sand fraction (0.063 mm < square mesh sieve size < 2 mm) shall 
include no more than 55 per cent natural sand and at least 45 per cent 
crushed sand; 
(b) The base and sub-base shall ensure a good stability and evenness, 
according to best road construction practice; 
(c) The chippings shall be crushed (100 per cent crushed faces) and of a 
material with a high resistance to crushing; E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
44   (d) The chippings used in the mix shall be washed; 
 (e) No extra chippings shall be added onto the surface; 
(f) The binder hardness expressed as PEN value shall be 40 - 60, 60 - 80 
or even 80 - 100 depending on the climatic conditions of the country. 
The rule is that as hard a binder as possible shall be used, provided 
this is consistent with common practice; 
(g) The temperature of the mix before rolling shall be chosen so as to 
achieve by subsequent rolling the required voids content. In order to 
increase the probability of satisfying the specifications of 
paragraphs 2.1. to 2.4. above, the compactness shall be studied not 
only by an appropriate choice of mixing temperature, but also by an 
appropriate number of passings and by the choice of compacting 
vehicle. 
Table 1 
Design guidelines 
 Target values  
 
Tolerances  By total mass  
of mix  By mass of the 
aggregate  
Mass of stones,  
square mesh sieve (SM) > 2 mm   
47.6 %  
50.5 %  
±5 % 
Mass of sand    0.063 < SM < 2 mm  38.0 % 40.2 % ±5 % 
Mass of filler   SM < 0.063 mm   8.8 % 9.3 % ±5 % 
Mass of binder (bitumen)   5.8 % N.A.  ±0.5 % 
Max. chipping  size 8 mm  6.3 - 10 mm  
Binder hardness  (see paragraph 3.2.2. (f))   
Polished Stone Value (PSV)  > 50  
Compactness, relative to Marshall  
Compactness  98 %   
4. Test method 
4.1. Measurement of the residual voids content 
 For the purpose of this measurement, cores have to be taken from the track in 
at least four different positions, which are equally distributed in the test are a 
between lines AA and BB (see Figure 1). In order to avoid in homogeneity 
and unevenness in the wheel tracks, cores should not be taken in wheel tracks 
themselves, but close to them. Two cores (minimum) should be taken close to 
the wheel tracks and one core (minimum) should be taken approximately 
midway between the wheel tracks and each microphone location. 
 If there is a suspicion that the condition of homogeneity is not met 
(see paragraph 2.4. above), cores shall be taken from more locations within 
the test area. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
 45  The residual voids content has to be determined for each core, then the 
average value from all cores shall be calculated and compared with the 
requirement of paragraph 2.1. of this annex. In addition, no single core shall 
have a voids value, which is higher than 10 per cent. 
 The test surface constructor is reminded of the problem, which may arise 
when the test area is heated by pipes or electrical wires and cores shall be 
taken from this area. Such installations shall be carefully planned with 
respect to future core drilling locations. It is recommended to leave a few 
locations of size approximately 200 mm x 300 mm where there are no 
wires/pipes or where the latter are located deep enough in order not to be 
damaged by cores taken from the surface layer. 
4.2. Sound absorption coefficient 
 The sound absorption coefficient (normal incidence) shall be measured by the 
impedance tube method using the procedure specified in ISO 10534 -1:1996 
or ISO 10534-2:1998. 
 Regarding test specimens, the same requirements shall be followed as 
regarding the residual voids content (see paragraph 4.1. above). The sound 
absorption shall be measured in the range between 400 Hz and 800 Hz and in 
the range between 800 Hz and 1,600 Hz (at least at the centre frequencies of 
third octave bands) and the maximum values shall be identified for both of 
these frequency ranges. Then these values, for all test scores, shall be 
averaged to constitute the final result. 
4.3. Volumetric macro-texture measurement 
 For the purpose of this standard, texture depth measurements shall be made 
on at least 10 positions evenly spaced along the wheel tracks of the test strip 
and the average value taken to compare with the specified minimum texture 
depth. See Standard ISO 10844:2014 for description of the procedure. 
5. Stability in time and maintenance 
5.1. Age influence 
 In common with any other surfaces, it is expected that the tyre rolling sound 
level measured on the test surface may increase slightly during the first  
6-12 months after construction. 
The surface will achieve its required characteristics not earlier than four 
weeks after construction. The influence of age on the noise from trucks is 
generally less than that from cars. 
 The stability over time is determined mainly by the polishing and compaction 
by vehicles driving on the surface. It shall be periodically checked as stated 
in paragraph 2.5. above. 
5.2. Maintenance of the surface 
 Loose debris or dust, which could significantly reduce the effective texture 
depth shall be removed from the surface. In countries with winter climates, 
salt is sometimes used for de-icing. Salt may alter the surface temporarily or 
even permanently in such a way as to increase noise and is therefore not 
recommended. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 4 
 
46  5.3. Repaving the test area 
 If it is necessary to repave the test track, it is usually unnecessary to repave 
more than the test strip (of 3 m width in Figure 1) where vehicles are driving, 
provided the test area outside the strip met the requirement of residual voids 
content or sound absorption when it was measured. 
6. Documentation of the test surface and of tests performed on it 
6.1. Documentation of the test surface 
 The following data shall be given in a document describing the test surface: 
6.1.1. The location of the test track; 
6.1.2. Type of binder, binder hardness, type of aggregate, maximum theoretical 
density of the concrete (DR), thickness of the wearing course and grading 
curve determined from cores from the test track; 
6.1.3. Method of compaction (e.g. type of roller, roller mass, number of passes); 
6.1.4. Temperature of the mix, temperature of the ambient air and wind speed 
during laying of the surface; 
6.1.5. Date when the surface was laid and contractor; 
6.1.6. All or at least the latest test result, including: 
6.1.6.1. The residual voids content of each core; 
6.1.6.2. The locations in the test area from where the cores for voids measurements 
have been taken; 
6.1.6.3. The sound absorption coefficient of each core (if measured). Specify the 
results both for each core and each frequency range as well as the overall 
average; 
6.1.6.4. The locations in the test area from where the cores for absorption 
measurement have been taken; 
6.1.6.5. Texture depth, including the number of tests and standard deviation; 
6.1.6.6. The institution responsible for tests according to paragraphs 6.1.6.1. 
and 6.1.6.2. above and the type of equipment used; 
6.1.6.7. Date of the test(s) and date when the cores were taken from the test track. 
6.2. Documentation of vehicle noise tests conducted on the surface 
 In the document describing the vehicle noise test(s) it shall be stated whether 
all the requirements of this standard were fulfilled or not. Reference shall be 
given to a document according to paragraph 6.1. above describing the results 
which verify this. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 47 Annex 5  
  Test procedures for measuring wet grip   
  (A) - C1 category tyres  
1.  Reference standards 
The following documents listed apply. 
1.1. ASTM E 303- 93 (Reapproved 2008), Standard Test Method for Measuring 
Surface Frictional Properties Using the British Pendulum Tester. 
1.2. ASTM E 501-08, Standard Specification for Standard Rib Tire for Pavement 
Skid-Resistance Tests. 
1.3. ASTM E 965-96 (Reapproved 2006), Standard Test Method for Measuring 
Pavement Macrotexture Depth Using a Volumetric Technique. 
1.4. ASTM E 1136-93 (Reapproved 2003), Standard Specification for a Radial 
Standard Reference Test Tire P195/75R14. 
1.5. ASTM F 2493-08, Standard Specification for a Radial Standard Reference 
Test Tire P225/60R16.  
2. Definitions 
For the purposes of testing wet grip of C1 tyres: 
2.1. "Test run"  means a single pass of a loaded tyre over a given test track 
surface. 
2.2. "Test tyre(s)"  means a candidate tyre, a reference tyre or a control tyre or tyre 
set that is used in a test run. 
2.3. "Candidate tyre(s) (T)"  means a tyre or a tyre set that is tested for the purpose 
of calculating its wet grip index. 
2.4. "Reference tyre(s) (R)" means a tyre or a tyre set that has the characteristics 
indicated in the ASTM F 2493-08 and referred to as the Standard Reference 
Test Tyre.  
2.5. "Control tyre(s) (C)"  means an intermediate tyre or a set of intermediate tyres 
which is used when the candidate tyre and the reference tyre cannot be 
directly compared on the same vehicle. 
2.6. "Braking force of a tyre"  means the longitudinal force, expressed in newton, 
resulting from braking torque application. 
2.7. "Braking Force Coefficient of a tyre (BFC )" means the ratio of the braking 
force to the vertical load. 
2.8. "Peak braking force coefficient of a tyre"  means the maximum value of a tyre 
braking force coefficient that occurs prior to wheel lockup as the braking 
torque is progressively increased. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
48  2.9. "Lockup of a wheel"  means the condition of a wheel in which its rotational 
velocity about the wheel spin axis is zero and it is prevented from rotating in 
the presence of applied wheel torque. 
2.10. "Vertical load"  means the load in newton imposed on the tyre perpendicular 
to the road surface. 
2.11. "Tyre test vehicle"  means a dedicated special purpose vehicle which has 
instruments to measure the vertical and the longitudinal forces on one test 
tyre during braking. 
2.12. "SRTT14" means the ASTM E 1136- 93 (Reapproved 2003), Standard 
Specification for a Radial Standard Reference Test Tire P195/75R14. 
2.13. "SRTT16" means the ASTM F 2493-08, Standard Specification for a Radial 
Standard Reference Test Tire P225/60R16. 
3. General test conditions 
3.1. Track characteristics 
The test track shall have the following characteristics: 
3.1.1. The surface shall have a dense asphalt surface with a uniform gradient of not 
more than 2 per cent and shall not deviate more than 6 mm when tested with 
a 3 m straight edge. 
3.1.2. The surface shall have a pavement of uniform age, composition, and wear. 
The test surface shall be free of loose material and foreign deposits. 
3.1.3. The maximum chipping size shall be 10 mm (tolerances permitted from 
8 mm to 13 mm). 
3.1.4. The texture depth as measured by a sand patch shall be 0.7 ± 0.3 mm. It shall 
be measured in accordance with ASTM E 965-96 (Reapproved 2006). 
3.1.5. The wetted frictional properties of the surface shall be measured with either 
method (a) or (b) in paragraph 3.2. 
3.2. Methods to measure the wetted frictional properties of the surface 
3.2.1. British Pendulum Number (BPN) method (a) 
 The British Pendulum Number method shall be as defined in ASTM E 303-93 
(Reapproved in 2008). 
 Pad rubber component formulation and physical properties shall be as 
specified in ASTM E 501- 08. 
 The averaged British Pendulum Number (BPN) shall be between 42 and 
60 BPN after temperature correction as follows. 
 BPN shall be corrected by the wetted road surface temperature. Unless 
temperature correction recommendations are indicated by the British 
pendulum manufacturer, the following formula is used: 
 BPN = BPN (measured value) + temperature correction 
 Temperature correction = -0.0018 t 2 + 0.34 t - 6.1 
 Where t  is the wetted road surface temperature in degrees Celsius. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 49  Effects of slider pad wear: the pad shall be removed for maximum wear when 
the wear on the striking edge of the slider reaches 3.2 mm in the plane of the 
slider or 1.6 mm vertical to it in accordance with paragraph 5.2.2. and 
Figure 3 of ASTM E 303-93 (Reapproved 2008). 
 For the purpose of checking track surface BPN consistency for the 
measurement of wet grip on an instrumented passenger car: the BPN values 
of the test track should not vary over the entire stopping distance so as to 
decrease the dispersion of test results. The wetted frictional properties of the 
surface shall be measured five times at each point of the BPN measurement 
every 10 meters and the coefficient of variation of the averaged BPN shall 
not exceed 10 per cent. 
3.2.2. ASTM E 1136 Standard Reference Test Tyre method (b)  
 By derogation with paragraph 2.4. above, this method uses the reference tyre 
that has the characteristics indicated in the ASTM E 1136-93 (Reapproved 
2003) and referred to as SRTT14. 
 The average peak braking force coefficient ( µpeak,ave ) of the SRTT14 shall be 
0.7 ± 0.1 at 65 km/h. 
 The average peak braking force coefficient ( µpeak,ave ) of the SRTT14 shall be 
corrected for the wetted road surface temperature as follows: 
 Peak braking force coefficient ( µpeak,ave ) = peak braking force coefficient 
(measured) + temperature correction 
 Temperature correction = 0.0035 x (t - 20) 
 Where t is the wetted road surface temperature in degrees Celsius. 
3.3. Atmospheric conditions 
 The wind conditions shall not interfere with wetting of the surface (wind-
shields are allowed). 
 Both the wetted surface temperature and the ambient temperature shall be 
between 2 °C and 20 °C for snow tyres and 5 °C and 35 °C for normal tyres. 
 The wetted surface temperature shall not vary during the test by more than 
10 °C. 
 The ambient temperature must remain close to the wetted surface 
temperature; the difference between the ambient and the wetted surface 
temperatures must be less than 10 °C. 
4. Testing methods for measuring wet grip 
 For the calculation of the wet grip index (G) of a candidate tyre, the wet grip 
braking performance of the candidate tyre is compared to the wet grip 
braking performance of the reference tyre on a vehicle travelling straight 
ahead on a wet, paved surface. It is measured with one of the following 
methods: 
(a) Vehicle method consisting of testing a set of tyres mounted on an 
instrumented passenger car; 
(b) Testing method using a trailer towed by a vehicle or a tyre test 
vehicle, equipped with the test tyre(s). E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
50  4.1. Testing method (a) using an instrumented passenger car 
4.1.1.  Principle  
 The testing method covers a procedure for measuring the deceleration 
performance of C1 tyres during braking, using an instrumented passenger car 
equipped with an Antilock Braking System (ABS), where "instrumented 
passenger car" means a passenger car that is fitted with the measuring 
equipment listed in paragraph 4.1.2.2. below for the purpose of this testing 
method. Starting with a defined initial speed, the brakes are applied hard 
enough on four wheels at the same time to activate the ABS. The average 
deceleration is calculated between two pre-defined speeds.  
4.1.2.  Equipment  
4.1.2.1. Vehicle 
 Permitted modifications on the passenger car are as follows: 
(a) Those allowing the number of tyre sizes that can be mounted on the 
vehicle to be increased; 
(b) Those permitting automatic activation of the braking device to be 
installed; 
(c) Any other modification of the braking system is prohibited. 
4.1.2.2. Measuring equipment 
 The vehicle shall be fitted with a sensor suitable for measuring speed on a 
wet surface and distance covered between two speeds.  
 To measure vehicle speed, a fifth wheel or non-contact speed-measuring 
system shall be used. 
4.1.3. Conditioning of the test track and wetting condition  
 The test track surface shall be watered at least half an hour prior to testing in 
order to equalize the surface temperature and water temperature. External 
watering should be supplied continuously throughout testing. For the whole 
testing area, the water depth shall be 1.0 ± 0.5 mm, measured from the peak 
of the pavement. 
 The test track should then be conditioned by conducting at least ten test runs 
with tyres not involved in the test programme at 90 km/h. 
4.1.4. Tyres and rims 
4.1.4.1. Tyre preparation and break- in 
 The test tyres shall be trimmed to remove all protuberances on the tread 
surface caused by mould air vents or flashes at mould junctions. 
Fit the test tyres on rims specified by a recognized tyre and rim standards 
organization as listed in Appendix 4 to Annex 6 to this Regulation. 
4.1.4.2. Tyre load 
 The static load on each axle tyre shall lie between 60 per cent and 90 per cent 
of the tested tyre load capacity. Tyre loads on the same axle should not differ 
by more than 10 per cent. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 51 4.1.4.3. Tyre inflation pressure 
 On the front and rear axles, the inflation pressures shall be 220 kPa (for 
standard- and extra-load tyres). The tyre pressure should be checked just 
prior to testing at ambient temperature and adjusted if required. 
4.1.5. Procedure  
4.1.5.1. Test run 
 The following test procedure applies for each test run. 
4.1.5.1.1. The passenger car is driven in a straight line up to 85 ± 2 km/h. 
4.1.5.1.2. Once the passenger car has reached 85 ± 2 km/h, the brakes are always 
activated at the same place on the test track referred to as "braking starting 
point", with a longitudinal tolerance of 5 m and a transverse tolerance of 0.5 m. 
4.1.5.1.3. The brakes are activated either automatically or manually.  
4.1.5.1.3.1. The automatic activation of the brakes is performed by means of a detection 
system made of two parts, one indexed to the test track and one on board the 
passenger car.  
4.1.5.1.3.2. The manual activation of the brakes depends on the type of transmission a s 
follows. In both cases, a minimum of 600 N pedal efforts is required. 
 For manual transmission, the driver should release the clutch and depress the 
brake pedal sharply, holding it down as long as necessary to perform the 
measurement. 
 For automatic transmission, the driver should select neutral gear and then 
depress the brake pedal sharply, holding it down as long as necessary to 
perform the measurement. 
4.1.5.1.4. The average deceleration is calculated between 80 km/h and 20 km/h. 
If any of the specifications listed above (including speed tolerance, 
longitudinal and transverse tolerance for the braking starting point, and 
braking time) are not met when a test run is made, the measurement is 
discarded and a new test run is made. 
4.1.5.2. Test cycle 
 A number of test runs are made in order to measure the wet grip index of a 
set of candidate tyres (T) according to the following procedure, whereby each 
test run shall be made in the same direction and up to three different sets of 
candidate tyres may be measured within the same test cycle: 
4.1.5.2.1. First, the set of reference tyres are mounted on the instrumented passenger 
car.  
4.1.5.2.2. After at least three valid measurements have been made in accordance with 
paragraph 4.1.5.1. above, the set of reference tyres is replaced by a set of 
candidate tyres.  
4.1.5.2.3. After six valid measurements of the candidate tyres are performed, two more 
sets of candidate tyres may be measured.  
4.1.5.2.4. The test cycle is closed by three more valid measurements of the same set of 
reference tyres as at the beginning of the test cycle.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
52   Examples: 
(a) The run order for a test cycle of three sets of candidate tyres (T1 to 
T3) plus a set of reference tyres (R) would be the following: 
 R- T1-T2-T3-R 
(b) The run order for a test cycle of five sets of candidate tyres (T1 to T5) 
plus a set of reference tyres (R) would be the following: 
 R- T1-T2-T3-R-T4-T5-R 
4.1.6. Processing of measurement results 
4.1.6.1. Calculation of the Average Deceleration (AD) 
 The Average Deceleration (AD) is calculated for each valid test run in m/s2 as 
follows:  
  
 Where: 
 Sf is the final speed in m/s; S f = 20 km/h = 5.556 m/s 
 Si is the initial speed in m/s; S i = 80 km/h = 22.222 m/s 
 d is the distance covered between S i and S f in meter. 
4.1.6.2. Validation of results 
 The AD coefficient of variation is calculated as follows: 
 (Standard deviation / Average) x 100. 
 For the reference tyres (R): If the AD coefficient of variation of any two 
consecutive groups of three tests runs of the reference tyre set is higher than 
3 per cent, all data should be discarded and the test repeated for all test tyres 
(the candidate tyres and the reference tyres). 
 For the candidate tyres (T): The AD coefficients of variation are calculated 
for each candidate tyre set. If one coefficient of variation is higher than 3 per 
cent, the data should be discarded and the test repeated for that candidate tyre 
set. 
4.1.6.3. Calculation of adjusted average deceleration (Ra) 
 The Average Deceleration (AD) of the reference tyre set used for the 
calculation of its braking force coefficient is adjusted according to the 
positioning of each candidate tyre set in a given test cycle.  
 This adjusted AD of the reference tyre (Ra) is calculated in m/s2 in 
accordance with Table 1 where R 1 is the average of the AD values in the first 
test of the reference tyre set (R) and R 2 is the average of the AD values in the 
second test of the same reference tyre set (R). d S S 
AD i f 
2   2 2 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 53 Table 1 
Number of sets of candidate  tyres 
within one test cycle  Set of candidate tyres  Ra 
1 
(R1-T1-R2) T1 Ra = 1/2 (R1 + R 2) 
2 
(R1-T1-T2-R2) T1 Ra = 2/3 R 1 + 1/3 R 2 
T2 Ra = 1/3 R 1 + 2/3 R 2 
3 
(R1-T1-T2-T3-R2) T1 Ra = 3/4 R 1 + 1/4 R 2 
T2 Ra = 1/2 (R 1 +R 2) 
T3 Ra = 1/4 R 1 + 3/4 R 2 
4.1.6.4. Calculation of the Braking Force Coefficient (BFC) 
 The Braking Force Coefficient (BFC) is calculated for a braking on the two 
axles according to Table 2 where Ta (a = 1, 2 or 3) is the average of the AD 
values for each candidate tyre (T) set that is part of a test cycle. 
Table 2 
Test Tyre  Braking force coeffic ient 
Reference tyre  BFC(R) = │Ra/g│  
Candidate tyre  BFC(T) = │Ta/g│  
g is the acceleration due to gravity, g = 9.81 m/s2 
4.1.6.5. Calculation of the wet grip index of the candidate tyre  
 The wet grip index of the candidate tyre G(T) is calculated as follows: 
  
 Where: 
 t  is the measured wet surface temperature in degree Celsius when 
the candidate tyre (T) is tested  
 t0  is the wet surface reference temperature condition, t 0 = 20 °C for 
normal tyres and t 0 = 10 °C for snow tyres 
 BFC(R 0) is the braking force coefficient for the reference tyre in the 
reference conditions, BFC(R 0) = 0.68 
 a = -0.4232 and b = -8.297 for normal tyres, a = 0.7721 and b = 31.18 
for snow tyres [a is expressed as (1/°C)] 2 
0 0 10 0 , 1 
) ( ) ( ) ( 125 
) ( ) ( ) (    
  
 
  
  
  
  
  
        
R BFC  R BFC  b t t a 
R BFC  T BFC  T G E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
54  4.1.7. Wet grip performance comparison between a candidate tyre and a reference 
tyre using a control tyre 
4.1.7.1. General 
 Where the candidate tyre size is significantly different from that of the 
reference tyre, a direct comparison on the same instrumented passenger car 
may not be possible. This testing method uses an intermediate tyre, 
hereinafter called the control tyre as defined in paragraph 2.5. above. 
4.1.7.2. Principle of the approach 
 The principle is the use of a control tyre set and two different instrumented 
passenger cars for the test cycle of a candidate tyre set in comparison with a 
reference tyre set. 
 One instrumented passenger car is fitted with the reference tyre set followed 
by the control tyre set, the other with the control tyre set followed by the 
candidate tyre set.  
 The specifications listed in paragraphs 4.1.2. to 4.1.4. above apply.  
 The first test cycle is a comparison between the control tyre set and the 
reference tyre set. 
 The second test cycle is a comparison between the candidate tyre set and the 
control tyre set. It is done on the same test track and during the same day as 
the first test cycle. The wetted surface temperature shall be within ±5 °C of 
the temperature of the first test cycle. The same control tyre set shall be used 
for the first and the second test cycles. 
 The wet grip index of the candidate tyre G(T) is calculated as follows: 
 G(T) = G 1 × G 2 
 Where: 
G1  is the relative wet grip index of the control tyre (C) compared to the 
reference tyre (R) calculated as follows: 
 
G2  is the relative wet grip index of the candidate tyre (T) compared to the 
control tyre (C) calculated as follows: 
  
4.1.7.3. Storage and preservation 
 It is necessary that all the tyres of a control tyre set have been stored in the 
same conditions. As soon as the control tyre set has been tested in 
comparison with the reference tyre, the specific storage conditions defined in 
ASTM E 1136-93 (Reapproved 2003) shall be applied. ) ( 2 C BFC  BFC  G  0 0 1 10-2 
 . 1 
) ( ) ( 
) ( 125 
) ( ) (   
  
 
  
  
  
  
          
R BFC  R BFC  
b t t a 
R BFC  C BFC  G 0 
( T ) E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 55 4.1.7.4. Replacement of reference tyres and control tyres 
 When irregular wear or damage results from tests, or when wear influences 
the test results, the use of the tyre shall be discontinued. 
4.2. Testing method (b) using a trailer towed by a vehicle or a tyre test vehicle 
4.2.1. Principle 
 The measurements are conducted on test tyres mounted on a trailer towed by 
a vehicle (hereafter referred to as tow vehicle) or on a tyre test vehicle. The 
brake in the test position is applied firmly until sufficient braking torque is 
generated to produce the maximum braking force that will occur prior to 
wheel lockup at a test speed of 65 km/h. 
4.2.2. Equipment 
4.2.2.1. Tow vehicle and trailer or tyre test vehicle 
 The tow vehicle or the tyre test vehicle shall have the capability of 
maintaining the specified speed of 65 ± 2 km/h even under the maximum 
braking forces. 
 The trailer or the tyre test vehicle shall be equipped with one place where the 
tyre can be fitted for measurement purposes hereafter called 'test position' and 
the following accessories: 
(a) Equipment to activate brakes in the test position; 
(b) A water tank to store sufficient water to supply the road surface 
wetting system, unless external watering is used; 
(c) Recording equipment to record signals from transducers installed at 
the test position and to monitor water application rate if the self-
watering option is used. 
The maximum variation of toe-settings and camber angle for the test position 
shall be within ±0.5° with maximum vertical load. Suspension arms and 
bushings shall have sufficient rigidity necessary to minimize free play and 
ensure compliance under application of maximum braking forces. The 
suspension system shall provide adequate load-carrying capacity and be of 
such a design as to isolate suspension resonance. 
The test position shall be equipped with a typical or special automotive brake 
system which can apply sufficient braking torque to produce the maximum 
value of braking test wheel longitudinal force at the conditions specified. 
The brake application system shall be able to control the time interval 
between initial brake application and peak longitudinal force as specified in 
paragraph 4.2.7.1. below. 
The trailer or the tyre test vehicle shall be designed to accommodate the 
range of candidate tyre sizes to be tested. 
The trailer or the tyre test vehicle shall have provisions for adjustment of 
vertical load as specified in paragraph 4.2.5.2. below E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
56  4.2.2.2. Measuring equipment 
The test wheel position on the trailer or the tyre test vehicle shall be equipped 
with a rotational wheel velocity measuring system and with transducers to 
measure the braking force and vertical load at the test wheel. 
General requirements for measurement system: The instrumentation system 
shall conform to the following overall requirements at ambient temperatures 
between 0 °C and 45 °C: 
(a) Overall system accuracy, force: ±1.5 per cent of the full scale of the 
vertical load or braking force; 
(b) Overall system accuracy, speed: ±1.5 per cent of speed or ±1.0 km/h, 
whichever is greater. 
Vehicle speed: To measure vehicle speed, a fifth wheel or non-contact 
precision speed-measuring system should be used. 
Braking forces: The braking force-measuring transducers shall measure 
longitudinal force generated at the tyre –road interface as a result of brake 
application within a range from 0 per cent to at least 125 per cent of the 
applied vertical load. The transducer design and location shall minimize 
inertial effects and vibration-induced mechanical resonance. 
Vertical load: The vertical load-measuring transducer shall measure the 
vertical load at the test position during brake application. The transducer shall 
have the same specifications as described previously. 
Signal conditioning and recording system: All signal conditioning and 
recording equipment shall provide linear output with necessary gain and data 
reading resolution to meet the specified previous requirements. In addition, 
the following requirements apply: 
(a) The minimum frequency response shall be flat from 0 Hz to 50 Hz 
(100 Hz) within ±1 per cent full scale; 
(b) The signal- to-noise ratio shall be at least 20/1; 
(c) The gain shall be sufficient to permit full-scale display for full-scale 
input signal level; 
(d) The input impedance shall be at least ten times larger than the output 
impedance of the signal source; 
(e) The equipment shall be insensitive to vibrations, acceleration, and 
changes in ambient temperature. 
4.2.3. Conditioning of the test track 
 The test track should be conditioned by conducting at least ten test runs with 
tyres not involved in the test program at 65 ± 2 km/h. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 57 4.2.4. Wetting conditions 
 The tow vehicle and trailer or the tyre test vehicle may be optionally 
equipped with a pavement-wetting system, less the storage tank, which, in the 
case of the trailer, is mounted on the tow vehicle. The water being applied to 
the pavement ahead of the test tyres shall be supplied by a nozzle suitably 
designed to ensure that the water layer encountered by the test tyre has a 
uniform cross section at the test speed with a minimum splash and overspray. 
 The nozzle configuration and position shall ensure that the water jets are 
directed towards the test tyre and pointed towards the pavement at an angle of 
20° to 30°. 
 The water shall strike the pavement 250 mm to 450 mm ahead of the centre 
of tyre contact. The nozzle shall be located 25 mm above the pavement or at 
the minimum height required to clear obstacles which the tester is expected to 
encounter, but in no case more than 100 mm above the pavement. 
 The water layer shall be at least 25 mm wider than the test tyre tread and 
applied so the tyre is centrally located between the edges. Water delivery rate 
shall ensure a water depth of 1.0 ± 0.5 mm and shall be consistent throughout 
the test to within ±10 per cent. The volume of water per unit of wetted width 
shall be directly proportional to the test speed. The quantity of water applied 
at 65 km/h shall be 18 l/s per meter of width of wetted surface in case of a 
water depth of 1.0 mm. 
4.2.5. Tyres and rims 
4.2.5.1. Tyre preparation and break- in 
 The test tyres shall be trimmed to remove all protuberances on the tread 
surface caused by mould air vents or flashes at mould junctions. 
 The test tyre shall be mounted on the test rim declared by the tyre 
manufacturer.  
 A proper bead seat should be achieved by the use of a suitable lubricant. 
Excessive use of lubricant should be avoided to prevent slipping of the tyre 
on the wheel rim. 
 The test tyres/rim assemblies shall be stored in a location for a minimum of 
two hours such that they all have the same ambient temperature prior to 
testing. They should be shielded from the sun to avoid excessive heating by 
solar radiation. 
 For tyre break-in, two braking runs shall be performed under the load, 
pressure and speed as specified in paragraphs 4.2.5.2, 4.2.5.3 and 4.2.7.1 
respectively. 
4.2.5.2. Tyre load 
 The test load on the test tyre is 75 ± 5 per cent of the tyre load capacity. 
4.2.5.3. Tyre inflation pressure 
 The test tyre cold inflation pressure shall be 180 kPa for standard-load tyres. 
For extra-load tyres, the cold inflation pressure shall be 220 kPa. 
 The tyre pressure should be checked just prior to testing at ambient temperature and 
adjusted if required.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
58  4.2.6. Preparation of the tow vehicle and trailer or the tyre test vehicle 
4.2.6.1. Trailer 
 For one axle trailers, the hitch height and transverse position shall be adjusted  
once the test tyre has been loaded to the specified test load in order to avoid 
any disturbance of the measuring results. The longitudinal distance from the 
centre line of the articulation point of the coupling to the transverse centre 
line of the axle of the trailer shall be at least ten times the "hitch height" or 
the "coupling (hitch) height". 
4.2.6.2. Instrumentation and equipment 
 Install the fifth wheel, when used, in accordance with the manufacturer’s 
specifications and locate it as near as possible to the mid-track position of the 
tow trailer or the tyre test vehicle. 
4.2.7. Procedure 
4.2.7.1. Test run 
 The following procedure applies for each test run: 
4.2.7.1.1. The tow vehicle or the tyre test vehicle is driven onto the test track in a 
straight line at the specified test speed 65 ± 2 km/h. 
4.2.7.1.2. The recording system is launched. 
4.2.7.1.3. Water is delivered to the pavement ahead of the test tyre approximately 0.5 s 
prior to brake application (for internal watering system). 
4.2.7.1.4. The trailer brakes are activated within 2 meters of a measurement point of the 
wetted frictional properties of the surface and sand depth in accordance with 
paragraphs 3.1.4. and 3.1.5. above. The rate of braking application shall be 
such that the time interval between initial application of force and peak 
longitudinal force is in the range 0.2 s to 0.5 s.  
4.2.7.1.5. The recording system is stopped. 
4.2.7.2. Test cycle 
 A number of test runs are made in order to measure the wet grip index of the 
candidate tyre (T) according to the following procedure, whereby each test 
run shall be made from the same spot on the test track and in the same 
direction. Up to three candidate tyres may be measured within the same test 
cycle, provided that the tests are completed within one day. 
4.2.7.2.1. First, the reference tyre is tested.  
4.2.7.2.2. After at least six valid measurements are performed in accordance with 
paragraph 4.2.7.1. above, the reference tyre is replaced by the candidate tyre.  
4.2.7.2.3. After six valid measurements of the candidate tyre are performed, two more 
candidate tyres may be measured.  
4.2.7.2.4. The test cycle is closed by six more valid measurements of the same 
reference tyre as at the beginning of the test cycle.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 59 Examples: 
(a) The run order for a test cycle of three candidate tyres (T1 to T3) plus 
the reference tyre (R) would be the following: 
 R- T1-T2-T3-R 
(b) The run order for a test cycle of five candidate tyres (T1 to T5) plus 
the reference tyre R would be the following: 
 R- T1-T2-T3-R-T4-T5-R 
4.2.8. Processing of measurement results 
4.2.8.1. Calculation of the peak braking force coefficient 
The tyre peak braking force coefficient (µ peak) is the highest value of µ(t) 
before lockup occurs calculated as follows for each test run. Analogue signals 
should be filtered to remove noise. Digitally recorded signals must be filtered 
using a moving average technique. 
Where: 
 µ(t)  is the dynamic tyre braking force coefficient in real time; 
 fh(t)  is the dynamic braking force in real time, in N; 
 fv(t)  is the dynamic vertical load in real time, in N. 
4.2.8.2. Validation of results 
 The µ peak coefficient of variation is calculated as follows:  
 (Standard deviation / Average) x 100 
 For the reference tyre (R): If the coefficient of variation of the peak braking 
force coefficient (µpeak) of the reference tyre is higher than 5 per cent, all data 
should be discarded and the test repeated for all test tyres (the candidate 
tyre(s) and the reference tyre). 
 For the candidate tyre(s) (T): The coefficient of variation of the peak braking 
force coefficient (µpeak) is calculated for each candidate tyre. If one 
coefficient of variation is higher than 5 per cent, the data should be discarded 
and the test repeated for this candidate tyre. 
4.2.8.3. Calculation of the adjusted average peak braking force coefficient 
 The average peak braking force coefficient of the reference tyre used for the 
calculation of its braking force coefficient is adjusted according to the 
positioning of each candidate tyre in a given test cycle. 
 This adjusted average peak braking force coefficient of the reference tyre 
(Ra) is calculated in accordance with Table 3 where R 1 is the average peak 
tyre braking coefficient in the first test of the reference tyre (R) and R 2 is the 
average peak tyre braking coefficient in the second test of the same reference 
tyre (R). ) ( ) ( ) ( t fv t fh t     E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
60  Table 3 
Number of candidate tyre(s) within one 
test cycle  Candidate tyre  Ra 
1 
(R1-T1-R2) T1 Ra = 1/2 (R 1 + R 2) 
2 
(R1-T1-T2-R2) T1 Ra = 2/3 R 1 + 1/3 R 2 
T2 Ra = 1/3 R 1 + 2/3 R 2 
3 
(R1-T1-T2-T3-R2) T1 Ra = 3/4 R 1 + 1/4 R 2 
T2 Ra = 1/2 (R 1 +R2) 
T3 Ra = 1/4 R 1 + 3/4 R 2 
4.2.8.4 Calculation of the average peak braking coefficient (µ peak,ave )  
The average value of the peak braking coefficients (µ peak,ave ) is calculated 
according to Table 4 whereby Ta (a = 1, 2 or 3) is the average of the peak 
braking force coefficients measured for one candidate tyre within one test 
cycle. 
Table 4 
Test tyre  µpeak,ave  
Reference tyre  µpeak,ave (R)=Ra as per Table 3  
Candidate tyre  µpeak,ave (T) = Ta  
4.2.8.5. Calculation of the wet grip index of the candidate tyre  
 The wet grip index of the candidate tyre (G(T)) is calculated as follows: 
2
0 ave , peakave , peak
0
ave , peakave , peak10 0 . 1) R () R (b ) t t ( a 125) R () T () T ( G








     
 
 Where: 
 t  is the measured wet surface temperature in degree Celsius 
when the candidate tyre (T) is tested 
 t0  is the wet surface reference temperature condition  
 t0 =  20 °C for normal tyres t 0=10°C for snow tyres 
 µpeak,ave (R0) = 0.85 is the peak braking force coefficient for the reference tyre 
in the reference conditions 
 a =  -0.4232 and b = -8.297 for normal tyres, a = 0.7721 and b = 
31.18 for snow tyres [a is expressed as (1/°C)]. 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 61 (B) – C2 and C3 category tyres 
1. General test conditions 
1.1. Track characteristics 
The surface shall be a dense asphalt surface with a uniform gradient of not 
more than two per cent and shall not deviate more than 6 mm when tested 
with a 3 m straight edge. 
The test surface shall have a pavement of uniform age, composition, and 
wear. The test surface shall be free of loose material or foreign deposits. 
The maximum chipping size shall be from 8 mm to 13 mm. 
The sand depth measured as specified in EN13036-1:2001 and ASTM E 965-
96 (reapproved 2006) shall be 0.7 ± 0.3 mm.  
The surface friction value for the wetted track shall be established by one or 
other of the following methods according to the discretion of the Contracting 
Party. 
1.1.1. Standard Reference Test Tyre (SRTT) method 
The average peak braking coefficient (μ peak average) of the ASTM E1136 -
93 (reapproved 2003) reference tyre (Test method using a trailer or a tyre test 
vehicle as specified in clause 2.1) shall be 0.7 +/- 0.1 (at 65 km/h and 
180 kPa). The measured values shall be corrected for the effects of 
temperature as follows: 
pbfc = pbfc (measured) + 0.0035 · (t - 20) 
Where "t" is the wetted track surface temperature in degrees Celsius. 
The test shall be conducted using the lanes and length of the track to be used 
for the wet grip test. 
For the trailer method, testing is run in such a way that braking occurs within 
10 meters distance of where the surface was characterized. 
1.1.2. British Pendulum Number (BPN) method 
The averaged British Pendulum Number (BPN) British Pendulum Tester 
method as specified in ASTM E 303-93 (reapproved 2008) using the Pad as 
specified in ASTM E 501-08 shall be (50 ± 10) BPN after temperature 
correction. 
BPN shall be corrected by the wetted road surface temperature. Unless 
temperature correction recommendations are indicated by the British 
pendulum manufacturer the following formula can be used: 
BPN = BPN (measured value) – (0.0018 · t²) + 0.34 · t - 6.1 
Where: "t" is the wetted road surface temperature in degrees Celsius. 
Effects of slider pad wear: the pad should be removed for maximum wear 
when the wear on the striking edge of the slider reaches 3.2 mm in the plane 
of the slider or 1.6 mm vertical to it.  
Check the test track testing surface BPN consistency for the measurement of 
wet grip on a standard vehicle. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
62  In the lanes of the track to be used during the wet grip tests, the BPN shall be 
measured at intervals of 10 m along the length of the lanes. The BPN shall be 
measured 5 times at each point and the coefficient of variation of the BPN 
averages shall not exceed 10 per cent. 
1.1.3. The Type Approval Authority shall satisfy itself of the characteristics of the 
track on the basis of evidence produced in test reports. 
1.2. The surface may be wetted from the track-side or by a wetting system 
incorporated into the test vehicle or the trailer. 
If a track-side system is used, the test surface shall be wetted for at least half 
an hour prior to testing in order to equalize the surface temperature and water 
temperature. It is recommended that track-side wetting be continuously 
applied throughout testing. 
The water depth shall be between 0.5 and 2.0 mm. 
1.3. The wind conditions shall not interfere with wetting of the surface (wind-
shields are permitted). 
The ambient and the wetted surface temperature shall be between 5 °C and 
35 °C and shall not vary during the test by more than 10 °C. 
1.4. In order to cover the range of the tyre sizes fitting the commercial vehicles, 
three Standard Reference Testing Tyre (SRTT) sizes shall be used to measure 
the relative wet index: 
(a) SRTT 315/70R22.5 LI=154/150, ASTM F2870 
(b) SRTT 245/70R19.5 LI=136/134, ASTM F2871 
(c) SRTT 225/75 R 16 C LI=116/114, ASTM F2872 
The three standard reference testing tyre sizes shall be used to measure the 
relative wet index as shown in the following table: 
For C3 tyres  
Narrow   family  
SNominal  < 285 mm  Wide family  
SNominal   > 285 mm  
SRTT 245/70R19.5  LI=136/134  SRTT 315/70R22.5 LI=154/150  
For C2 tyres  
SRTT 225/75 R 16 C LI=116/114  
SNominal = Tyre nominal section width  
2.  Test procedure 
  The comparative wet grip performance shall be established using either: 
(a) A trailer or special purpose tyre evaluation vehicle; or 
(b) A standard production vehicle (M 2, M 3, N1, N2 or N 3, category) as 
defined in the Consolidated Resolution on the Construction of 
Vehicles (R.E.3.) contained in ECE/TRANS/WP.29/78/Rev.4, para. 2. 
2.1.  Trailer or special purpose tyre evaluation vehicle procedure 
2.1.1. The measurements are conducted on (a) tyre(s) mounted on a trailer towed by 
a vehicle or a tyre test vehicle. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 63 The brake on the test position is applied firmly until sufficient braking torque 
results to produce maximum braking force that will occur prior to wheel 
lockup at a test speed of 50 km/h. The trailer, together with the towing 
vehicle, or the tyre evaluation vehicle shall comply with the following 
requirements: 
2.1.1.1. Be capable of exceeding the upper limit for the test speed of 50 km/h and of 
maintaining the test speed requirement of (50  2) km/h even at the 
maximum level of application of braking forces; 
2.1.1.2. Be equipped with an axle providing one test position having an hydraulic 
brake and actuation system that can be operated at the test position from the 
towing vehicle if applicable. The braking system shall be capable of 
providing sufficient braking torque to achieve the peak brake force 
coefficient over the range of tyre sizes and tyre loads to be tested; 
2.1.1.3. Be capable of maintaining longitudinal alignment (toe) and camber of the test 
wheel and tyre assembly throughout the test within 0.5° of the static figures 
achieved at the test tyre loaded condition; 
2.1.1.4. In the case a track wetting system is incorporated: 
The system shall be able to deliver the water such that the tyre and track 
surface in front of the tyre are wetted before the start of braking and 
throughout the duration of the test. The apparatus may be optionally equipped 
with a pavement-wetting system, less the storage tank, which, in the case of 
the trailer, is mounted on the tow vehicle. The water being applied to the 
pavement ahead of the test tyres shall be supplied by a nozzle suitably 
designed to ensure that the water layer encountered by the test tyre has a 
uniform cross section at the test speed with a minimum splash and overspray. 
The nozzle configuration and position shall ensure that the water jets shall be 
directed toward the test tyre and pointed toward the pavement at an angle of 
15 to 30°. The water shall strike the pavement 0.25 to 0.5 m ahead of the 
centre of tyre contact. The nozzle shall be located 100 mm above the 
pavement or the minimum height required to clear obstacles which the tester 
is expected to encounter, but in no case more than 200 mm above the 
pavement. The water layer shall be at least 25 mm wider than the test tyre 
tread and applied so the tyre is centrally located between the edges. The 
volume of water per unit of wetted width shall be directly proportional to the 
test speed. The quantity of water applied at 50 km/h shall be 14 l/s per meter 
of the width of the wetted surface. The nominal values of rate of water 
application shall be maintained within 10 per cent. 
2.1.2. Test procedure 
2.1.2.1. Fit the test tyres on rims specified by a recognized tyre and rim standards 
organization as listed in Appendix 4 to Annex 6 to this Regulation. Ensure 
proper bead seating by the use of a suitable lubricant. Excessive use of 
lubricant should be avoided to prevent slipping of the tyre on the wheel rim. 
Check the test tyres for the specified inflation pressure at ambient 
temperature (cold), just prior to testing. For the purpose of this standard the 
testing tyre cold inflation pressure P t shall be calculated as follows: 
25. 1
rt
r tQQP P


 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
64  Where: 
Pr = Inflation pressure marked on the sidewall. If P r is not marked on the 
sidewall refer to the specified pressure in applicable tyre standards 
manuals corresponding to maximum load capacity for single 
applications 
Qt = The static test load of the tyre 
Qr = The maximum mass associated with the load capacity index of the 
tyre 
2.1.2.2. For tyre break-in, two braking runs are performed. The tyre shall be 
conditioned for a minimum of two hours adjacent to the test track such that it 
is stabilized at the ambient temperature of the test track area. The tyre(s) shall 
not be exposed to direct sunshine during conditioning. 
2.1.2.3. The load conditions for testing shall be 75  5 per cent of the value 
corresponding to the load index. 
2.1.2.4. Shortly before testing, the track shall be conditioned by carrying out at least 
ten braking test runs at 50 km/h on the part of the track to be used for the 
performance test programme but using a tyre not involved in that 
programme; 
2.1.2.5. Immediately prior to testing, the tyre inflation pressure shall be checked and 
reset, if necessary, to the values given in paragraph 2.1.2.1. 
2.1.2.6. The test speed shall be at 50  2 km/h and shall be maintained between these 
limits throughout the test run. 
2.1.2.7. The direction of the test shall be the same for each set of tests and shall be the 
same for the test tyre as that used for the SRTT with which its performance is 
to be compared. 
2.1.2.8. Deliver water to the pavement ahead of the test tyre approximately 0.5 s prior 
to brake application (for internal watering system). The brakes of the test 
wheel assembly shall be applied such that peak braking force is achieved 
within 0.2 s and 1.0 s of brake application.  
2.1.2.9. For new tyres, the first two braking runs are discarded for tyre bre ak-in. 
2.1.2.10. For the evaluation of the performance of any tyre compared with that of the 
SRTT, the braking test should be run at the same area on the test pad. 
2.1.2.11. The order of testing shall be: 
R1 - T - R2 
 Where: 
 R1 = the initial test of the SRTT,  
R2 = the repeat test of the SRTT and  
T = the test of the candidate tyre to be evaluated. 
A maximum of three candidate tyres may be tested before repeating the 
SRTT test, for example: 
R1 - T1 - T2 - T3 - R2 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 65 2.1.2.12. Calcu late the peak braking force coefficient, μ peak, for each test using the 
following equation: 
  
 t ft ftμ
vh
                     (1) 
Where: 
μ(t) = dynamic tyre braking force coefficient in real time, 
fh(t) = dynamic braking force in real time, N, 
fv(t) = dynamic vertical load in real time, N 
Using equation (1) for dynamic tyre braking force coefficient, calculate the 
peak tyre braking force coefficient, μ peak, by determining the highest value of 
μ(t) before lockup occurs. Analogic signals should be filtered to remove 
noise. Digitally recorded signals may be filtered using a moving average 
technique.  
Calculate the average values of peak- braking coefficient (μ peak, ave ) by 
averaging four or more valid repeated runs for each set of test and reference 
tyres for each test condition provided that the tests are completed within the 
same day. 
2.1.2.13. Validation of results 
For the reference tyre: 
If the coefficient of variation of the peak braking coefficient, which is 
calculated by "standard deviation/average x 100" of the reference tyre is 
higher than five per cent, discard all data and repeat the test for this reference 
tyre.  
For the candidate tyres: 
The coefficients of variation (standard deviation/average x 100) are 
calculated for all the candidate tyres. If one coefficient of variation is greater 
than five per cent, discard the data for this candidate tyre and repeat the test. 
If R 1 is the average of the peak braking coefficient in the first test of the 
reference tyre, R 2 is the average of the peak braking coefficient in the second 
test of the reference tyre, the following operations are performed, according 
to the following table: 
If the number of sets of candidate 
tyres between two successive runs of 
the reference tyre is:  and the set of 
candidate tyres to be 
qualified is:  then "Ra" is calculated by 
applying the following:  
1     R1 – T1 – R2 T1 Ra = 1/2 (R 1 + R 2) 
2     R1 – T1 - T2 – R2 T1 
T2 Ra = 2/3 R 1 + 1/3 R 2 
Ra = 1/3 R 1 + 2/3 R 2 
3     R1 – T1 - T2 - T3 – R2 T1 
T2 
T3 Ra = 3/4 R 1 + 1/4 R 2 
Ra = 1/2 (R 1 + R 2) 
Ra = 1/4 R 1 + 3/4 R 2 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
66  2.1.2.14. The wet grip index (G) shall be calculated as: 
Wet grip index (G) = μ peak,ave  (T)/μ peak, ave  (R) 
It represents the relative Wet Grip Index for braking performance of the 
candidate tyre (T) compared to the reference tyre (R). 
2.2. Standard vehicle procedure 
2.2.1. The vehicle used shall have two axles and be equipped with an anti-lock 
braking system (e.g. standard production vehicle of M 2, M 3, N 1, N 2 or N 3 
category). The ABS shall continue to fulfil the utilisation of adhesion 
requirements defined in the Regulations as appropriate, and shall be 
comparable and constant throughout the tests with the different tyres 
mounted. 
2.2.1.1. Measuring equipment 
The vehicle shall be fitted with a sensor suitable for measuring speed on a 
wet surface and distance covered between two speeds. 
To measure vehicle speed, a fifth wheel or non-contact speed-measuring 
system shall be used. 
The following tolerances shall be respected: 
(a) For the speed measurements: ±1 per cent or ±0.5 km/h whichever is 
greater; 
(b) For the distance measurements: ±1 x 10-1 m. 
A display of the measured speed or the difference between the measured 
speed and the reference speed for the test can be used inside the vehicle so 
that the driver can adjust the speed of the vehicle. 
A data acquisition system can be also used for storing the measurements. 
2.2.2. Test procedure 
Starting with a defined initial speed, the brakes are applied hard enough on 
the two axles at the same time to activate the ABS system.  
2.2.2.1. The Average Deceleration (AD) is calculated between two defined speeds, 
with an initial speed of 60 km/h and a final speed of 20 km/h.  
2.2.2.2. Vehicle equipment 
The rear axle may be indifferently fitted with 2 or 4 tyres.  
For the reference tyre testing, both axles are fitted with reference tyres. (A 
total of 4 or 6 reference tyres depending on the choice above mentioned).  
For the candidate tyre testing, 3 fitting configurations are possible: 
(a) Configuration "Configuration 1": Candidate tyres on front and rear 
axles: it is the standard configuration that should be used every time it 
is possible.  
(b) Configuration "Configuration 2": Candidate tyres on front axle and 
reference tyre or control tyre on rear axle: allowed in such cases where 
fitting the candidate tyre on the rear position is not possible.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 67 (c) Configuration "Configuration 3": Candidate tyres on rear axle and 
reference tyre or control tyre on front axle: permitted in such cases 
where fitting the candidate tyre on the front position is not possible. 
2.2.2.3. Tyre inflation pressure 
(a) For a vertical load higher or equal to 75 per cent of the load capacity 
of the tyre, the test inflation pressure "P t" shall be calculated as 
follows: 
Pt = P r  · (Q t/Qr)1.25 
Pr = Inflation pressure marked on the sidewall. If P r is not marked 
on the sidewall refer to the specified pressure in applicable tyre 
standards manuals corresponding to maximum load capacity 
for single applications 
Qt = static test load of the tyre 
Qr = maximum mass associated with the load capacity index of the 
tyre 
(b) For a vertical load lower than 75 per cent of the load capacity of the 
tire, the test inflation pressure P t shall be calculated as follows: 
Pt = P r · (0.75)1.25 = (0.7) · Pr  
Pr = Inflation pressure marked on the sidewall. 
If P r is not marked on the sidewall refer to the specified pressure in applicable 
tyre standard manuals corresponding to maximum load capacity for single 
applications. 
Check the tyre pressure just prior to testing at ambient temperature. 
2.2.2.4. Tyre load 
The static load on each axle shall remain the same throughout the test 
procedure. The static load on each tyre shall lie between 60 per cent and 
100 per cent of the candidate tyre's load capacity. This value shall not exceed 
100 per cent of the load capacity of the reference tyre. 
Tyre load on the same axle should not differ by more than 10 per cent. 
The use of fitting as per Configurations 2 and 3 shall fulfil the following 
additional requirements: 
Configuration 2: Front axle load > Rear axle load 
The rear axle may be indifferently fitted with 2 or 4 tyres 
Configuration 3: Rear axle load > Front axle load x 1.8 
2.2.2.5. Tyre preparation and break- in 
2.2.2.5.1. The test tyre shall be mounted on the test rim declared by the tyre 
manufacturer. 
Ensure proper bead seating by the use of a suitable lubricant. Excessive use 
of lubricant should be avoided to prevent slipping of the tyre on the wheel 
rim. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
68  2.2.2.5.2. Place the fitted test tyres in a location for a minimum of two hours such that 
they all have the same ambient temperature prior to testing, and shield them 
from the sun to avoid excessive heating by solar radiation. For tyre break-in, 
perform two braking runs. 
2.2.2.5.3. Condition the pavement by conducting at least ten test runs with tyres not 
involved in the test programme at an initial speed higher or equal to 65 km/h 
(which is higher than the initial test speed to guarantee that a sufficient length 
of track is conditioned). 
2.2.2.6. Procedure 
2.2.2.6.1. First, mount the set of reference tyres on the vehicle. 
The vehicle accelerates in the starting zone up to 65 ± 2 km/h. 
Activation of the brakes on the track is made always at the same place with a 
tolerance of 5 meters in longitudinal and 0.5 meters in transverse. 
2.2.2.6.2. According to the type of transmission, two cases are possible: 
(a) Manual transmission 
As soon as the driver is in the measuring zone and having reached 
65 ± 2 km/h, the clutch is released and the brake pedal depressed 
sharply, holding it down as long as necessary to perform the 
measurement. 
(b) Automatic transmission 
As soon as the driver is in the measuring zone and having reached 
65 ± 2 km/h, select neutral gear and then the brake pedal is depressed 
sharply, holding it down as long as necessary to perform the 
measurement. 
Automatic activation of the brakes can be performed by means of a detection 
system made of two parts, one indexed to the track and one embarked on the 
vehicle. In that case braking is made more rigorously at the same portion of 
the track. 
If any of the above-mentioned conditions are not met when a measurement is 
made (speed tolerance, braking time, etc.), the measurement is discarded and 
a new measurement is made. 
2.2.2.6.3. Test running order  
Examples: 
The run order for a test of 3 sets of candidate tyres (T1 to T3) plus a reference 
tyre R would be:  
R - T1 - T2 - T3 - R 
The run order for a test of 5 sets of tyres (T1 to T5) plus a reference tyre R 
would be:  
R - T1 - T2 - T3 - R -T4 - T5 – R 
2.2.2.6.4. The direction of the test shall be the same for each set of tests and shall be the 
same for the candidate test tyre as that used for the SRTT with which its 
performance is to be compared. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 69 2.2.2.6.5. For each test and for new tires, the first two braking measurements are 
discarded. 
2.2.2.6.6. After at least 3 valid measurements have been made in the same direction, the 
reference tyres are replaced by a set of the candidate tyres (one of the 3 
configurations presented in paragraph 2.2.2.2.) and at least 6 valid 
measurements shall be performed. 
2.2.2.6.7. A maximum of three sets of candidate tyres can be tested before the reference 
tyre is re-tested. 
2.2.2.7. Processing of measurement results 
2.2.2.7.1. Calculation of the Average Deceleration (AD) 
Each time the measurement is repeated, the average deceleration AD [ m∙s-²) 
is calculated by: 
dS SADi f
22 2
 
Where d [m] is the distance covered between the initial speed S i [m∙s-1] and 
the final speed S f [m∙s-1]. 
2.2.2.7.2. Validation of results 
For the reference tyre: 
If the coefficient of variation of "AD" of any two consecutive groups of 3 
runs of the reference tyre is higher than 3 per cent, discard all data and repeat 
the test for all tyres (the candidate tyres and the reference tyre). The 
coefficient of variation is calculated by the following relation: 
100averagedeviation  standard
 
For the candidate tyres: 
The coefficients of variation are calculated for all the candidate tyres. 
100averagedeviation  standard
 
If one coefficient of variation is greater than 3 per cent, discard the data for 
this candidate tyre and repeat the test. 
2.2.2.7.3. Calculation of the "average AD" 
If R 1 is the average of the AD values in the first test of the reference tyre and 
R2 is the average of the AD values in the second test of the reference tyre, the 
following operations are performed, according to Table 5. 
Ra is the adjusted average AD of the reference tyre. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
70  Table 5 
Number of sets of candidate  
tyres between two successive  
runs of the reference tyre  Set of candidate  
tyres to be 
qualified  Ra 
1   R1 -T1-R2 T1 Ra = 1/2 (R 1 + R 2) 
2   R1 -T1-T2-R2 T1 
T2 Ra = 2/3 R 1 + 1/3 R 2 
Ra = 1/3 R 1 + 2/3 R 2 
3   R1 -T1-T2-T3-R2 T1 
T2 
T3 Ra = 3/4 R 1 + 1/4 R 2 
Ra = 1/2 (R 1 + R 2) 
Ra = 1/4 R 1 + 3/4 R 2 
2.2.2.7.4. Calculation of braking force coefficient, BFC 
BFC(R) and BFC(T) are calculated according to Table 6: 
Table 6 
Tyre type  Braking force coefficient is  
Reference tyre  BFC(R) = Ra/g  
Candidate tyre  BFC(T) = Ta/g  
g is the acceleration due to gravity (rounded to 9.81 m ⋅s−2). 
Ta (a = 1, 2, etc.) is the average of the AD values for a test of a candidate 
tyre. 
2.2.2.7.5. Calculation of the relative wet grip performance index of the tyre 
The Wet grip index represents the relative performance of the candidate tyre 
compared to the reference tyre. The way to obtain it depends on the test 
configuration as defined in paragraph 2.2.2.2. of this annex. The wet grip 
index of the tyre is calculated as reported into Table 7: 
Table 7 
Configuration C1:  
candidate tyres on both axles  
) R ( BFC) T ( BFCIndex Grip Wet 
Configuration C2:  
candidate tyres on front axle 
and reference tyres on rear axle  
 
 ) T ( BFC h b ) R ( BFC) R ( BFC a ) R ( BFC h b a ) T ( BFCIndex Grip Wet        
Configuration C3:  
reference tyres on front axle 
and candidate tyres on rear axle  
 
 ) T ( BFC h a ) R ( BFC) R ( BFC b ) R ( BFC h b a ) T ( BFCIndex Grip Wet          
Where: 
"G":  centre of gravity of the loaded vehicle  
"m":  mass (in kilograms) of the loaded vehicle E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5  
 
 71 "a":  horizontal distance between front axle and centre of gravity of the 
loaded vehicle (m) 
"b":  horizontal distance between rear axle and centre of gravity of the 
loaded vehicle  
"h":  vertical distance between ground level and centre of gravity of the 
loaded vehicle (m).  
N.B. When "h" is not precisely known, these worst case values shall apply: 
1.2 for configuration C2, and 1.5 for configuration C3 
"" loaded vehicle acceleration [ m∙s-²]  
"g" acceleration due to the gravity [ m∙s-²]  
"X1" longitudinal (X-direction) reaction of the front tyre on the road  
"X2" longitudinal (X-direction) reaction of the rear tyre on the road  
"Z1" normal (Z-direction) reaction of the front tyre on the road  
"Z2" normal (Z-direction) reaction of the rear tyre on the road  
Figure 1  
Nomenclature explanation related to grip index of the tyre 
 
 
2.2.2.8. Wet grip performance comparison between a candidate tyre and a reference 
tyre using a control tyre 
When the candidate tyre size is significantly different from the reference tyre, 
a direct comparison on the same vehicle may be not possible. This approach 
uses an intermediate tyre, hereinafter called the control tyre. 
2.2.2.8.1. The principle lies upon the use of a control tyre and 2 different vehicles for 
assessing a candidate tyre in comparison with a reference tyre. 
m.ɣ 
X1 X2 m.g h b a 
Z1
g Z2
g E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 
 
72  One vehicle can fit the reference tyre and the control tyre, the other the 
control tyre and the candidate tyre. All conditions are in conformity with 
paragraphs 2.2.1.2. to 2.2.2.5. above. 
2.2.2.8.2. The first assessment is a comparison between the control tyre and the 
reference tyre. The result (Wet Grip Index 1) is the relative efficiency of the 
control tyre compared to the reference tyre. 
2.2.2.8.3. The second assessment is a comparison between the candidate tyre and the 
control tyre. The result (Wet Grip Index 2) is the relative efficiency of the 
candidate tyre compared to the control tyre. 
The second assessment is done on the same track as the first one and within 
one week maximum. The wetted surface temperature shall be in the range of 
+5°C of the temperature of the first assessment. The control tyre set (4 or 6 
tyres) is physically the same set as the set used for the first assessment. 
2.2.2.8.4. The wet grip index of the candidate tyre compared to the reference tyre is 
deduced by multiplying the relative efficiencies calculated above: 
(Wet Grip Index 1 · Wet Grip Index 2) 
Note : When the test expert decides to use an SRTT tyre as a control tyre (i.e. 
in the test procedure two SRTTs are compared directly instead of an SRTT 
with a control tyre) the result of the comparison between the SRTTs is called 
the "local shift factor".  
It is permitted to use a previous SRTTs comparison.  
The comparison results shall be checked periodically. 
2.2.2.8.5. Selection of a set of tyres as a control tyre set 
A "control tyre" set is a group of identical tyres made in the same factory 
during a one week period. 
2.2.2.8.6. Reference and control tyres 
Before the first assessment (control tyre / reference tyre), normal storage 
conditions can be used. It is necessary that all the tyres of a control tyre set 
have been stored in the same conditions. 
2.2.2.8.7. Storage of control tyres 
As soon as the control tyre set has been assessed in comparison with the 
reference tyre, specific storage conditions shall be applied for control tyres 
replacement. 
2.2.2.8.8. Replacement of reference and control tyres 
 When irregular wear or damage results from tests, or when wear influences 
the test results, the use of the tyre shall be discontinued. 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 - Appendix 
 
 73 Annex 5 – Appendix 
  Test reports examples of wet grip index 
Example 1:  Test report of wet grip index using trailer method 
Test report number:   Test date:  
Type of road surface:   Texture depth (mm):  
 µ peak (SRTT14  E1136) :   or BPN:  
Speed (km/h):   Water depth (mm):  
 
No. 1 2 3 4 5 6 7 8 9 10 
Size           
Service description            
Tyre identification            
Rim           
Pattern            
Load (N)            
Pressure (kPa)            
µpeak  1           
 2           
 3           
 4           
 5           
 6           
 7           
 8           
Average            
Standard deviation σ           
(σ/average)≤5 per cent            
Ra, Adjusted            
Wet grip index            
Surface temp. (°C)            
Ambient temp. (°C)            
Remarks            
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 5 - Appendix  
 
74  Example 2:  Test report of wet grip index using passenger car method 
Driver:   Test date:    
     
Track:   Passenger car:   Initial speed (km/h):  
 Texture depth (mm):   Brand:   Final speed (km/h):  
 BPN:   Model:    
 Water depth (mm):   Type    
 
No. 1 2 3 4 5 
Brand  Uniroyal  TYRE B  TYRE C  TYRE D  Uniroyal  
Pattern  ASTM F 2493 
SRTT16  PATTERN B  PATTERN C  PATTERN D  ASTM F 2493 
SRTT16  
Size P225/60R16  SIZE B  SIZE C  SIZE D  P225/60R16  
Service description  97S LI/SS  LI/SS  LI/SS  97S 
Tyre identification  XXXXXXXXX  YYYYYYYYY  ZZZZZZZZZ  NNNNNNNNN  XXXXXXXXX  
Rim      
Front axle pressure (kPa)       
Rear axle pressure (kPa)       
Front axle load (kg)       
Rear axle load (kg)       
Wet surface temp (°C)       
Ambient temp (°C)       
 Braking 
distance  
(m) Average  
deceleration 
(m/s2) Braking 
distance 
(m) Average  
deceleration 
(m/s2) Braking  
distance 
(m) Average  
deceleration 
(m/s2) Braking 
distance 
(m) Average 
deceleration  
(m/s2) Braking 
distance 
(m) Average 
deceleration  
(m/s2) 
Measurement  1           
 2           
 3           
 4           
 5           
 6           
 7           
 8           
 9           
 10           
Average AD (m/s2)      
Standard deviation (m/s2)      
Validation of results  
Coeff. of variation (per 
cent) < 3 per cent       
Adjusted average AD of 
ref. tyre:  Ra (m/s2)      
BFC(R) reference tyre 
(SRTT16)       
BFC (T) candidate tyre       
Wet grip index (%)       E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 75 Annex 6 
  Test procedure for measuring rolling resistance 
1. Test methods 
 The alternative measurement methods listed below are given in this 
Regulation. The choice of an individual method is left to the tester. For each 
method, the test measurements shall be converted to a force acting at the 
tyre/drum interface. The measured parameters are: 
(a) In the force method: the reaction force measured or converted at the 
tyre spindle;1 
 (b) In the torque method: the torque input measured at the test drum;2 
(c) In the deceleration method: the measurement of deceleration of the 
test drum and tyre assembly;2 
(d) In the power method: the measurement of the power input to the test 
drum.2 
2. Test equipment 
2.1. Drum specifications 
2.1.1. Diameter 
 The test dynamometer shall have a cylindrical flywheel (drum) with a 
diameter of at least 1.7 m. 
 The F r and C r values shall be expressed relative to a drum diameter of 2.0 m. 
If drum diameter different than 2.0 m is used, a correlation adjustment shall 
be made following the method in paragraph 6.3. of this annex. 
2.1.2. Surface 
 The surface of the drum shall be smooth steel. Alternatively, in order to 
improve skim test reading accuracy, a textured surface may also be used, 
which should be kept clean. 
 The F r and C r values shall be expressed relative to the "smooth" drum 
surface. If a textured drum surface is used, see Appendix 1, paragraph 7. 
2.1.3. Width 
 The width of the drum test surface shall exceed the width of the test tyre 
contact patch. 
  
 1 This measured value also includes the bearing and aerodynamic losses of the wheel and tyre which 
are also to be considered for further data interpretation. 
 2 The measured value in the torque, deceleration and power methods also includes the bearing and 
aerodynamic losses of the wheel, the tyre, and the drum which are also to be considered for further 
data interpretation. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
76 2.2. Measuring rim (see Appendix 2) 
The tyre shall be mounted on a steel or light alloy measuring rim, as follows: 
(a) For Class C1 tyres, the width of the rim shall be as defined in 
ISO 4000 -1:2010, 
(b) For Class C2 and C3 tyres, the width of the rim shall be as defined in 
ISO 4209 1:2001. 
In cases where the width is not defined in the above mentioned ISO 
Standards, the rim width as defined by one of the standards organizations as 
specified in Appendix 4 may be used. 
2.3. Load, alignment, control and instrumentation accuracies 
 Measurement of these parameters shall be sufficiently accurate and precise to 
provide the required test data. The specific and respective values are shown 
in Appendix 1. 
2.4. Thermal environment 
2.4.1. Reference conditions 
 The reference ambient temperature, measured at a distance not less 
than 0.15 m and not more than 1 m from the tyre sidewall, shall be 25 C. 
2.4.2. Alternative conditions 
 If the test ambient temperature is different from the reference ambient 
temperature, the rolling resistance measurement shall be corrected to the 
reference ambient temperature in accordance with paragraph 6.2. of this 
annex. 
2.4.3. Drum surface temperature. 
 Care should be taken to ensure that the temperature of the test drum surface is 
the same as the ambient temperature at the beginning of the test. 
3. Test conditions 
3.1. General 
 The test consists of a measurement of rolling resistance in which the tyre is 
inflated and the inflation pressure allowed to build up, i.e., "capped air". 
3.2. Test speeds 
 The value shall be obtained at the appropriate drum speed specified in 
Table 1. 
Table 1 
Test Speeds (in km/h) 
Tyre Class  C1 C2 and C3  C3 
Load index  All LI ≤ 121  LI > 121  
Speed symbol  All All J 100 km/h and lower or tyres 
not marked with speed symbol  K 110 km/h 
and higher  
Speed  80 80 60 80 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 77 3.3. Test load 
 The standard test load shall be computed from the values shown in Table 2 
and shall be kept within the tolerance specified in Appendix 1. 
3.4. Test inflation pressure 
 The inflation pressure shall be in accordance with that shown in Table 2 and 
shall be capped with the accuracy specified in paragraph 4. of Appendix 1 to 
this annex. 
Table 2 
Test loads and inflation pressures 
Tyre Class  C1 (a) C2, C3  
 Standard 
load Reinforced or extra load   
Load  - % of 
maximum load 
capacity   
80  
80  
85(b) 
(% of single load)  
Inflation  pressure  
kPa  
210  
250 Corresponding to maximum load 
capacity for single application(c) 
Note : The inflation pressure shall be capped with the accuracy specified in paragraph  4. of 
 Appendix  1 to this annex.  
(a) For those passenger car tyres belonging to categories which are not shown in ISO  4000 -1:2010, 
the inflation pressure shall be the inflation pressure recommended by the tyre manufacturer, 
corresponding to the maximum tyre  load capacity, reduced by 30  kPa. 
(b) As a percentage of single load, or 85 per cent of maximum load capacity for single application 
specified in applicable tyre standards manuals if not marked on tyre.  
(c) Inflation pressure marked on sidewall, or if not  marked on sidewall, as specified in applicable 
tyre standards manuals corresponding to maximum load capacity for single application.  
3.5. Duration and speed. 
When the deceleration method is selected, the following requirements apply: 
(a) The deceleration j shall be determined in differential dω/dt or discrete 
Δω/Δt form, where ω is angular velocity, t –  time; 
If the differential form dω/dt is used, then the recommendations of 
Appendix 5 to this annex are to be applied. 
 (b) For duration Δt , the time increments shall not exceed 0.5 s; 
(c) Any variation of the test drum speed shall not exceed 1 km/h within 
one time increment. 
4. Test procedure 
4.1. General 
 The test procedure steps described below shall be followed in the sequence 
given. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
78 4.2. Thermal conditioning 
 The inflated tyre shall be placed in the thermal environment of the test 
location for a minimum of: 
(a) 3 hours for Class C1 tyres; 
(b) 6 hours for Class C2 and C3 tyres. 
4.3. Pressure adjustment 
 After thermal conditioning, the inflation pressure shall be adjusted to the test 
pressure, and verified 10 minutes after the adjustment is made. 
4.4. Warm- up 
 The warm-up durations shall be as specified in Table 3. 
Table 3 
Warm up durations 
Tyre Class  C1 C2 and C3  
LI ≤ 121  C3 
LI > 121  
Nominal Rim Diameter  All All < 22.5  ≥ 22.5  
Warm up duration  30 min.  50 min.  150 min.  180 min.  
4.5. Measurement and recording 
 The following shall be measured and recorded (see Figure 1): 
 (a) Test speed U n; 
 (b) Load on the tyre normal to the drum surface L m; 
 (c) The initial test inflation pressure as defined in paragraph 3.3. above; 
(d) The coefficient of rolling resistance measured C r, and its corrected 
value C rc, at 25 °C and for a drum diameter of 2 m; 
(e) The distance from the tyre axis to the drum outer surface under steady 
state r L,; 
 (f) Ambient temperature t amb; 
 (g) Test drum radius R; 
 (h) Test method chosen; 
 (i) Test rim (size and material); 
(j) Tyre size, manufacturer, type, identity number (if one exists), speed 
symbol, load index, DOT number (Department of Transportation). E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 79 Figure 1 
 
 
All the mechanical quantities (forces, torques) will be orientated in 
accordance with the axis systems specified in ISO 8855:1991. 
 The directional tyres shall be run in their specified rotation sense. 
4.6. Measurement of parasitic losses 
 The parasitic losses shall be determined by one of the following procedures 
given in paragraph 4.6.1. or 4.6.2. below. 
4.6.1. Skim test reading 
 Skim test reading follows the procedure below: 
(a) Reduce the load to maintain the tyre at the test speed without 
slippage.3 
  The load values should be as follows: 
(i) Class C1 tyres: recommended value of 100 N; not to exceed 
200 N; 
(ii) Class C2 tyres: recommended value of 150 N; not to exceed 
200 N for machines designed for Class C1 tyre measurement or 
500 N for machine designed for Class C2 and C3 tyres; 
(iii) Class C3 tyres: recommended value of 400 N; not to exceed 
500 N. 
(b) Record the spindle force F t, input torque T t, or the power, whichever 
applies;3 
(c) Record the load on the tyre normal to the drum surface L m3. 
  
 3 With the exception of the force method, the measured value includes the bearing and aerodynamic 
losses of the wheel, the tyre, and the drum losses which also need to be considered. 
  It is known that the spindle and drum bearing frictions depend on the applied load. Consequently, it is 
different for the loaded system measurement and the skim test reading. However, for practical 
reasons, this difference can be disregarded. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
80 4.6.2. Deceleration method 
The deceleration method follows the procedure below: 
(a) Remove the tyre from the test surface; 
(b) Record the deceleration of the test drum  Do/ t and that of the 
unloaded tyre  T0/ t or record the deceleration of the test drum j D0 
and that of the unloaded tyre j T0 in exact or approximate form in 
accordance with paragraph 3.5. above. 
4.7. Allowance for machines exceeding σ m criterion 
 The steps described in paragraphs 4.3. to 4.5. above shall be carried out once 
only, if the measurement standard deviation determined in accordance with 
paragraph 6.5. below is: 
 (a) Not greater than 0.075 N/kN for Class C1 and C2 tyres; 
 (b) Not greater than 0.06 N/kN for Class C3 tyres. 
 If the measurement standard deviation exceeds this criterion, the 
measurement process will be repeated n times as described in paragraph 6.5. 
below. The rolling resistance value reported shall be the average of the n 
measurements. 
5. Data interpretation 
5.1. Determination of parasitic losses 
5.1.1. General 
 The laboratory shall perform the measurements described in paragraph 4.6.1. 
above for the force, torque and power methods or those described in 
paragraph 4.6.2. above for the deceleration method, in order to determine 
precisely in the test conditions (load, speed, temperature) the tyre spindle 
friction, the tyre and wheel aerodynamic losses, the drum (and as appropriate, 
engine and/or clutch) bearing friction, and the drum aerodynamic losses. 
 The parasitic losses related to the tyre/drum interface F pl expressed in newton 
shall be calculated from the force F t torque, power or the deceleration, as 
shown in paragraphs 5.1.2. to 5.1.5. below. 
5.1.2. Force method at tyre spindle 
 Calculate: F pl = F t (1  rL/R) 
Where:  
Ft  is the tyre spindle force in newton (see paragraph  4.6.1.  above ), 
rL  is the distance from the tyre axis to the drum outer surface 
under steady state conditions, in meter , 
R  is the test drum radius, in meter.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 81 5.1.3. Torque method at drum axis 
 Calculate: F pl = T t/R 
Where:  
Tt  is the input torque in newton meter, as determined in 
paragraph  4.6.1 , 
R  is the test drum radius, in meter.  
5.1.4. Power method at drum axis 
 Calculate: 
nplUA V 6 , 3F  
Where:  
V  is the electrical potential applied to the machine drive, in volt , 
A  is the electric current drawn by the machine drive, in ampere,  
Un  is the test drum speed, in kilometer per hour.  
5.1.5. Deceleration method 
 Calculate the parasitic losses F pl, in newton. 




 



 
00 T
rT
00 D D
plRI
t RIF
 
Where:  
ID  is the test drum inertia in rotation, in kilogram meter squared,  
R  is the test drum surface radius, in meter,  
D0  is the test drum angular speed, without tyre, in radians per 
second,  
t0  is the time increment chosen for the measurement of the 
parasitic losses without tyre, in second,  
IT  is the spindle, tyre and wheel inertia in rotation, in kilogram 
meter squared,  
Rr  is the tyre rolling radius, in meter , 
T0  is the tyre angular speed, unloaded tyre, in radian per second.  
or  
T0
rT
D0D
pl jRIjRIF  
 
 
Where:    
ID  is the test drum inertia in rotation, in kilogram meter squared,  
R  is the test drum surface radius, in meter,  
jD0  is the deceleration of the test drum, without tyre, in radians per 
second squared,  
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
82 IT  is the spindle, tyre and wheel inertia in rotation, in kilogram 
meter squared,  
Rr  is the tyre rolling radius, in meter , 
jT0  is the deceleration of unloaded tyre, in radians per second 
squared.  
5.2. Rolling resistance calculation 
5.2.1. General 
 The rolling resistance F r, expressed in newton, is calculated using the values 
obtained by testing the tyre to the conditions specified in this international 
standard and by subtracting the appropriate parasitic losses F pl, obtained 
according to paragraph 5.1. above. 
5.2.2. Force method at tyre spindle 
 The rolling resistance Fr, in newton, is calculated using the equation 
Fr = F t[1  (rL/R)]  Fpl 
Where:  
Ft  is the tyre spindle force i n newton,  
Fpl  represents the parasitic losses as calculated in paragraph  5.1.2.  
above , 
rL  is the distance from the tyre axis to the drum outer surface 
under steady -state conditions, in meter , 
R  is the test drum radius, in meter . 
5.2.3. Torque method at drum axis 
 The rolling resistance F r, in newton, is calculated with the equation 
t
r plTFFR
 
Where:  
Tt  is the input torque, in newton meter , 
Fpl  represents the parasitic losses as calculated in paragraph  5.1.3.  
above , 
R  is the test drum radius, in meter . 
5.2.4. Power method at drum axis 
 The rolling resistance F r, in newton, is calculated with the equation: 
r pl
n3,6VAFFU
 
Where:    
V = is the electrical potential applied to the machine drive, in volt , 
A = is the electric current drawn by the machine drive, in ampere,  3.6V x A E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 83 Un = is the test dr um speed, in kilometer  per hour,  
Fpl = represents the parasitic losses as calculated in paragraph  5.1.4.  
above.  
 
5.2.5. Deceleration method 
The rolling resistance Fr, in newton, is calculated using the equation: 
pl
VV
2
rT
VV DFtω
RI R
tω
RIFr 



 




 
Where:    
ID  is the test drum inertia in rotation, in kilogram meter  squared,  
R  is the test drum surface radius, in meter,  
Fpl  represents the parasitic losses as calculated in paragraph  5.1.5.  
above , 
tv  is the time increment chosen for measurement, in second,  
Δv  is the test drum angular speed increment, without tyre, in 
radian per second,  
IT  is the spindle, tyre and wheel inertia in rotation, in kilogram 
meter  squared,  
Rr  is the tyre rolling radius, in meter , 
Fr  is the rolling resistance, in newton.  
 
or 
pl V 2
rT
VDF j
RI RjRIFr  
 
Where:    
ID  is the test drum inertia in rotation, in kilogram meter  squared,  
R  is the test drum surface radius, in meter,  
Fpl  represents the parasitic losses as calculated in paragraph  5.1.5.  
above , 
jV  is the deceleration of  the test drum, in radians per second 
squared,  
IT  is the spindle, tyre and wheel inertia in rotation, in kilogram 
meter  squared,  
Rr  is the tyre rolling radius, in meter , 
Fr  is the rolling resistance, in newton.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
84 6. Data analysis 
6.1. Rolling resistance coefficient 
 The rolling resistance coefficient C r is calculated by dividing the rolling 
resistance by the load on the tyre: 
CF
Lrr
m
 
Where:    
Fr
  is the rolling resistance, in newton,  
Lm
  is the test load, in kN.  
6.2. Temperature correction 
 If measurements at temperatures other than 25 C are unavoidable (only 
temperatures not less than 20 C or more than 30 C are acceptable), then a 
correction for temperature shall be made using the following equation, with: 
 Fr25 is the rolling resistance at 25 C, in Newton: 
   F F K tr r amb 25 1 25   
 
Where:   
Fr
 is the rolling resistance, in Newton,  
tamb
 is the ambient temperature, in degree Celsius,  
K
 is equal to:  
0.008  for Class C1 tyres  
0.010  for Class C2 and C3 tyres with a load index equal or 
lower than 121  
0.006  for Class C3 tyres with a load index greater than 121  
6.3. Drum diameter correction 
 Test results obtained from different drum diameters shall be compared by 
using the following theoretical formula: 
F KFr r 02 01
 
 With: 
  
 TT
r Rr R R RK
12 2 1
 
Where:    
R1
  is the radius of drum 1, in meter , 
R2
  is the radius of drum 2, in meter , 
rT
  is one -half of the nominal  design tyre diameter, in meter,  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 
 
 85 
01rF  is the rolling resistance value measured on drum 1, in  newton,  
Fr02
  is the rolling resistance value measured on drum 2, in newton.  
6.4. Measurement result 
 Where n measurements are greater than 1, if required by paragraph 4.6. 
above, the measurement result shall be the average of the C r values obtained 
for the n measurements, after the corrections described in paragraphs 6.2. 
and 6.3. above have been made. 
6.5. The laboratory shall ensure that, based on a minimum of three measurements, 
the machine maintains the following values of σ m, as measured on a single 
tyre: 
 σm  ≤ 0.075 N/kN for tyres of Classes C1 and C2  
 σm  ≤ 0.06 N/kN for tyres of Class C3  
 If the above requirement for σ m is not met, the following formula shall be 
applied to determine the minimum number of measurements n (rounded to 
the immediate superior integer value) that are required by the machine to 
qualify for conformance with this Regulation. 
n = (σ m/ x)² 
 Where: 
 x = 0.075 N/kN for tyres of Classes C1 and C2 
 x = 0.06 N/kN for tyres of Class C3 
 If a tyre needs to be measured several times, the tyre/wheel assembly shall be 
removed from the machine between the successive measurements. 
 If the removal/refitting operation duration is less than 10 minutes, the warm-
up durations indicated in paragraph 4.3. above may be reduced to: 
 (a) 10 minutes for tyres of Class C1; 
 (b) 20 minutes for tyres of Class C2; 
 (c) 30 minutes for tyres of Class C3. 
6.6. Monitoring of the laboratory control tyre shall be carried out at intervals no 
greater than one month. Monitoring shall include a minimum of 3 separate 
measurements taken during this one month period. The average of the 
3 measurements taken during a given one-month period shall be evaluated for 
drift from one monthly evaluation to another. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 - Appendix 1 
 
86  Annex 6 - Appendix 1 
  Test equipment tolerances 
1. Purpose 
 The limits specified in this annex are necessary in order to achieve suitable 
levels of repeatable test results, which can also be correlated among various 
test laboratories. These tolerances are not meant to represent a complete set 
of engineering specifications for test equipment; rather, they should serve as 
guidelines for achieving reliable test results. 
2. Test rims 
2.1. Width 
For passenger car tyre rims (C1 tyres), the test rim width shall be the same as 
the measuring rim determined in ISO 4000 -1: 2010 , clause 6.2.2. 
For truck and bus tyres (C2 and C3), the rim width shall be the same as the 
measuring rim determined in ISO 4209 -1:2001, clause 5.1.3. 
In cases where the width is not defined in the above mentioned ISO 
Standards, the rim width as defined by one of the standards organizations as 
specified in Appendix 4 to Annex 6 may be use d. 
2.2. Run-out 
 Run-out shall meet the following criteria: 
 (a) Maximum radial run-out: 0.5 mm; 
 (b) Maximum lateral run-out: 0.5 mm. 
3. Drum / tyre alignment 
 General: 
 Angle deviations are critical to the test results. 
3.1. Load application 
 The direction of tyre loading application shall be kept normal to the test 
surface and shall pass through the wheel centre within 
 (a) 1 mrad for the force and deceleration methods; 
 (b) 5 mrad for the torque and power methods. 
3.2. Tyre alignment 
3.2.1. Camber angle 
 The plane of the wheel shall be perpendicular to the test surface within 
2 mrad for all methods. 
3.2.2. Slip angle 
 The plane of the tyre shall be parallel to the direction of the test surface 
motion within 1 mrad for all methods. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 - Appendix 1 
 
 87 4. Control accuracy 
 Test conditions shall be maintained at their specified values, independent of 
perturbations induced by the tyre and rim non-uniformity, such that the 
overall variability of the rolling resistance measurement is minimized. In 
order to meet this requirement, the average value of measurements taken 
during the rolling resistance data collection period shall be within the 
accuracies stated as follows: 
 (a) Tyre loading: 
  (i) For LI ≤ 121  ±20 N or ±0.5 per cent, whichever is greater; 
  (ii) For LI > 121 ±45 N or ±0.5 per cent whichever is greater; 
 (b) Cold inflation pressure: ±3 kPa; 
 (c) Surface speed: 
  (i) ±0.2 km/h for the power, torque and deceleration methods; 
  (ii) ±0.5 km/h for the force method; 
 (d) Time:  
(i) ±0.02 s for the time increments specified in Annex 6, 
paragraph 3.5.(b) for the data acquisition in the deceleration 
method in ∆ω/∆t form;  
(ii) ±0.2 per cent for the time increments specified in Annex 6, 
paragraph 3.5.(a) for the data acquisition in the deceleration 
method in dω/dt form;  
(iii) ±5 per cent for the other time durations specified in Annex 6. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 - Appendix 1 
 
88  5. Instrumentation accuracy 
 The instrumentation used for readout and recording of test data shall be 
accurate within the tolerances stated below: 
Parameter  Load Index ≤ 121 Load Index > 121  
Tyre load  ±10 N or ±0.5  % (a) ±30 N or ±0.5  % (a) 
Inflation pressure  ±1 kPa ±1.5 kPa 
Spindle force  ±0.5 N or ±0.5  % (a) ±1.0 N or ±0.5  % (a) 
Torque input  ±0.5 Nm or ±0.5  % (a) ±1.0 Nm or ±0.5  % (a) 
Distance  ±1 mm ±1 mm 
Electrical power  ±10 W ±20 W 
Temperature  ±0.2 °C 
Surface speed  ±0.1 km/h  
Time  ±0.01  s - ±0.1 % - ±10 s(b)  
Angular velocity  ±0.1 % 
(a)  Whichever is greater. 
(b)  ±0.01 s for the time increments specified in Annex 6, paragraph 3.5.(b) for the data acquisition in 
the deceleration method in ∆ω/∆t form  
±0.1 per cent for the time increments specified in Annex 6, paragraph 3.5.(a) for the data acquisition 
in the deceleration method in dω/dt form  
± 10 sec for the other time durations specified in Annex 6. 
6. Compensation for load/spindle force interaction and load misalignment for 
the force method only 
 Compensation of both load/spindle force interaction ("cross talk") and load 
misalignment may be achieved either by recording the spindle force for both 
forward and reverse tyre rotation or by dynamic machine calibration. If 
spindle force is recorded for forward and reverse directions (at each test 
condition), compensation is achieved by subtracting the "reverse" value from 
the "forward" value and dividing the result by two. If dynamic machine 
calibration is intended, the compensation terms may be easily incorporated in 
the data reduction. 
 In cases where reverse tyre rotation immediately follows the completion of 
the forward tyre rotation, a warm-up time for reverse tyre rotation shall be at 
least 10 minutes for Class C1 tyres and 30 minutes for all other tyre types. 
7. Test surface roughness 
 The roughness, measured laterally, of the smooth steel drum surface shall 
have a maximum centreline average height value of 6.3 m. 
 Note:  In cases where a textured drum surface is used instead of a smooth 
steel surface, this fact is noted in the test report. The surface texture shall then 
be 180 m deep (80 grit) and the laboratory is responsible for maintaining the 
surface roughness characteristics. No specific correction factor is 
recommended for cases where a textured drum surface is used. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 - Appendix 2 
 
 89 Annex 6 - Appendix 2 
  Measuring rim width 
1. Class C1 tyres 
 The measuring rim width R m is equal to the product of the nominal section 
width S N and the coefficient K 2: 
Rm = K 2 x S N 
 rounded to the nearest standardized rim, where K 2 is the rim/section width 
ratio coefficient. For tyres mounted on 5° drop-centre rims with a nominal 
diameter expressed by a two-figure code: 
  K 2 = 0.7 for nominal aspect ratios 95 to 75 
  K 2= 0.75 for nominal aspect ratios 70 to 60 
  K 2 = 0.8 for nominal aspect ratios 55 and 50 
  K 2 = 0.85 for nominal aspect ratio 45 
  K 2 = 0.9 for nominal aspect ratios 40 to 30 
  K 2 = 0.92 for nominal aspect ratios 20 and 25 
2. Class C2 and C3 tyres 
 The measuring rim width R m is equal to the product of the nominal section 
width S N, and the coefficient K 4: 
  R m = K 4 x S N rounded to the nearest standardized rim width. 
Table 1 
Coefficients for determining measuring rim width 
Tyre structure code  Type of rim  Nominal aspect ratio H/S  Measuring rim/ section ratio K 4 
B, D, R  5º tapered  100 to 75  0.70 
70 and 65  0.75 
60 0.75 
55 0.80 
50 0.80 
45 0.85 
40 0.90 
15º tapered  
(drop -centre)  90 to 65  0.75 
60 0.80 
55 0.80 
50 0.80 
45 0.85 
40 0.85 
Note : Other factors may be established for new tyre concepts  (structures).  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 - Appendix 3 
 
90  Annex 6 - Appendix 3 
  Test report and test data (Rolling resistance) 
Part 1:  Report 
1. Type Approval Authority or Technical Service:  ...............................................   
2. Name and address of applicant:  ........................................................................   
3. Test report No.: ..................................................................................................  
4. Manufacturer and brand name or trade description:  .........................................   
5. Tyre class (C1, C2 or C3):  ................................................................................   
6. Category of use:  ................................................................................................   
7. Rolling resistance coefficient 
(temperature and drum diameter corrected):  .....................................................   
8. Comments (if any):  ...........................................................................................   
9. Date:  .................................................................................................................   
10. Signature:  ..........................................................................................................   
Part 2:  Test data 
1. Date of test:  .......................................................................................................  
2. Test machine identification and drum diameter/surface:  ..................................  
3. Test tyre details:  ................................................................................................   
3.1. Tyre size designation and service description:  .................................................   
3.2. Tyre brand and trade description:  .....................................................................  
3.3. Reference inflation pressure:  ......................................................................  kPa 
4. Test data: ...........................................................................................................   
4.1. Measurement method:  ......................................................................................   
4.2. Test speed:  ............................................................................................... km/h 
4.3. Load:  .............................................................................................................  N 
4.4. Test inflation pressure, initial:  ....................................................................  kPa 
4.5. Distance from the tyre axis to the drum outer surface under steady state 
conditions, r L: ................................................................................................  m 
4.6. Test rim width and material:  .............................................................................   
4.7. Ambient temperature:  ..................................................................................  °C 
4.8. Skim test load (except deceleration method) :  ...............................................  N 
5. Rolling resistance coefficient:  ..........................................................................   
5.1. Initial value (or average in the case of more than 1):  ............................... N/kN 
5.2. Temperature corrected: ............................................................................. N/kN 
5.3. Temperature and drum diameter corrected:  ............................................. N/kN E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 – Appendix 4 
 
 91 Annex 6 – Appendix 4 
  Tyre standards organizations 
1. The Tire and Rim Association, Inc. (TRA) 
2. The European Tyre and Rim Technical Organisation (ETRTO) 
3. The Japan Automobile Tyre Manufacturers’ Association (JATMA)  
4. The Tyre and Rim Association of Australia (TRAA) 
5. South Africa Bureau of Standards (SABS) 
6. China Association for Standardization (CAS) 
7. Indian Tyre Technical Advisory Committee (ITTAC) 
8. International Standards Organisation (ISO) E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 – Appendix 5 
 
92  Annex 6 – Appendix 5 
  Deceleration method: Measurements and data processing for 
deceleration value obtaining in differential form dω/dt.  
1. Record dependency "distance-time" of rotating body decelerated from 
peripheral with a speed range such as 82 to 78 km/h or 62 to 58 km/h 
dependent on tyre class (Annex 6, paragraph 3.2., Table 1) in a discrete form 
(Figure 1) for a rotating body: 
z = f(t z) 
Where: 
z is a number of body revolutions during deceleration; 
tz is end time of revolution number z in seconds recorded with 6 digits after 
zero. 
Figure 1 
0 t t t tz
4 1t2 3zzz4
1z23
1234
 
Note 1 : The lower speed of the recording range may be reduced down to 
60 km/h when test speed is 80 km/h and 40 km/h when the test speed is 
60 km/h. 
2. Approximate recorded dependency by continuous, monotonic, differentiable 
function: 
2.1. Choose the value nearest to the maximum of z dividable by 4 and divide it 
into 4 equal parts with bounds: 0, z 1(t1), z 2(t2), z 3(t3), z 4(t4). 
2.2. Work out the system for 4 equations each of the form: 
 
BTcos) t T ( B coslnA zm
m
 
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 – Appendix 5 
 
 93 Where unknowns: 
A is a dimensionless constant, 
B is a constant in revolutions per second, 
TΣ is a constant in seconds, 
m is the number of bounds shown in figure 1. 
Insert in these 4 equations the coordinates of 4-th bound above. 
2.3. Take constants A, B and T Σ as the solution of the equation system of 
paragraph 2.2. above using iteration process and approximate measured data 
by formulae: 
BTcos) t T ( B coslnA ) t ( z
 
Where: 
z(t) is the current continuous angular distance in number of revolutions (not 
only integer values); 
t is time in seconds. 
Note 2 : Other approximating functions z = f(t z) may be used if their adequacy 
is proven. 
3. Calculate the deceleration j in revolutions per second squared (s-2) by the 
formula: 
AABj2
2 
 
Where: 
ω is the angular speed in revolutions per second (s-1). 
For the case Un = 80 km/h; ω = 22.222/R r (or R). 
For the case Un = 60 km/h; ω = 16.666/R r (or R). 
4. Estimate the quality of approximation of measured data and its accuracy by 
parameters: 
4.1. Standard deviation in percentages: 
%100z) t ( z11 n1n
12

 
 
4.2. Coefficient of determination 
 
 
 

 n
12n
12
2
z z) t ( z z
1 R
 E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 6 – Appendix 5 
 
94  Where: 
 2n 1n 2 1n1zn1zn
1 z      

 
Note 3 : The above calculations for this variant of the deceleration method for 
tyre rolling resistance measurement can be executed by the computer 
program "Deceleration Calculator" downloadable from the WP.29 website1 
as well as any software which allows the calculation of nonlinear regression. 
  
 1 http://www.unece.org/trans/main/wp29/wp29wgs/wp29gen/deceleration_calculator.html.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 95 Annex 7 
  Procedures for snow performance testing relative to snow 
tyre for use in severe snow conditions 
1.  Specific definitions for snow test when different from existing ones 
1.1. " Test run " means a single pass of a loaded tyre over a given test surface. 
1.2. " Braking test " means a series of a specified number of ABS-braking test runs 
of the same tyre repeated within a short time frame. 
1.3. " Traction test " means a series of a specified number of spin-traction test runs 
according to ASTM standard F1805-06 of the same tyre repeated within a 
short time frame. 
1.4. " Acceleration test " means a series of specified number of traction controlled 
acceleration test runs of the same tyre repeated within a short timeframe. 
2. Spin traction method for Class C1 and C2 tyres (traction force test per 
paragraph 6.4. (b) of this Regulation) 
 The test procedure of ASTM standard F1805-06 shall be used to assess snow 
performance through spin traction values on medium packed snow (The snow 
compaction index measured with a CTI penetrometer1 shall be between 
70 and 80). 
2.1. The test course surface shall be composed of a medium packed snow surface, 
as characterized in table A2.1 of ASTM standard F1805- 06. 
2.2. The tyre load for testing shall be as per option 2 in paragraph 11.9.2. of 
ASTM standard F1805- 06. 
3. Braking on snow method for Class C1 and C2 tyres  
3.1. General conditions 
3.1.1. Test course 
The braking tests shall be done on a flat test surface of sufficient length and 
width, with a maximum 2 per cent gradient, covered with packed snow. 
The snow surface shall be composed of a hard packed snow base at leas t 
3 cm thick and a surface layer of medium packed and prepared snow about 
2 cm thick. 
The air temperature, measured about one meter above the ground, shall be 
between -2 °C and - 15 °C; the snow temperature, measured at a depth of 
about one centimeter, shall be between -4 °C and - 15 °C. 
 It is recommended to avoid direct sunlight, large variations of sunlight or 
humidity, as well as wind. 
  
 1 See appendix of ASTM standard F18 05-06 for details. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
96   The snow compaction index measured with a CTI penetrometer1 shall be 
between 75 and 85. 
3.1.2. Vehicle 
 The test shall be conducted with a standard production vehicle in good 
running order and equipped with an ABS system. 
 The vehicle used shall be such that the loads on each wheel are appropriate to 
the tyres being tested. Several different tyre sizes can be tested on the same 
vehicle. 
3.1.3. Tyres 
 The tyres should be "broken-in" prior to testing to remove spew, compound 
nodules or flashes resulting from the moulding process. The tyre surface in 
contact with snow shall be cleaned before performing a test. 
 Tyres shall be conditioned at the outdoor ambient temperature at least two 
hours before their mounting for tests. Tyre pressures shall then be adjusted to 
the values specified for the test. 
 In case a vehicle cannot accommodate both the reference and candidate tyres , 
a third tyre ("control" tyre) may be used as an intermediate. First test control 
vs. reference on another vehicle, then test candidate vs. control on the 
vehicle. 
3.1.4. Load and pressure 
3.1.4.1. For C1 tyres, the vehicle load shall be such that the resulting loads on the 
tyres are between 60 per cent and 90 per cent of the load corresponding to 
the tyre load index. 
 The cold inflation pressure shall be 240 kPa. 
3.1.4.2.  For C2 tyres, the vehicle load shall be such that the resulting loads on the  
tyres are between 60 per cent and 100 per cent of the load corresponding to 
the tyre load index. 
 The static tyre load on the same axle should not differ by more than 10 per 
cent. 
 The inflation pressure is calculated to run at constant deflection: 
 For a vertical load higher or equal to 75 per cent of the load capacity of the 
tyre, a constant deflection is applied, hence the test inflation pressure "Pt" 
shall be calculated as follows: 
25. 1




rt
r tQQP P
 
 Qr is the maximum load associated to the load capacity index of the tyre 
written on the sidewall 
 Pr is the reference pressure corresponding to the maximum load capacity Qr 
 Qt is the static test load of the tyre E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 97  For a vertical load lower than 75 per cent of the load capacity of the tyre, a 
constant inflation pressure is applied, hence the test inflation pressure Pt shall 
be calculated as follows: 
 
 r r t P P P ) 7 . 0 ( 75. 025. 1   
 Pr is the reference pressure corresponding to the maximum load capacity Qr 
 Check the tyre pressure just prior to testing at ambient temperature. 
3.1.5. Instrumentation 
 The vehicle shall be fitted with calibrated sensors suitable for measurements 
in winter. There shall be a data acquisition system to store measurements. 
 The accuracy of measurement sensors and systems shall be such that the 
relative uncertainty of the measured or computed mean fully developed 
decelerations is less than 1 per cent. 
3.2. Testing sequences 
3.2.1. For every candidate tyre and the standard reference tyre, ABS-braking test 
runs shall be repeated a minimum of 6 times. 
 The zones where ABS-braking is fully applied shall not overlap. 
 When a new set of tyres is tested, the runs are performed after shifting aside 
the vehicle trajectory in order not to brake on the tracks of the previous tyre. 
 When it is no longer possible not to overlap full ABS-braking zones, the test 
course shall be re-groomed. 
Required sequence: 
6 repeats SRTT, then shift aside to test next tyre on fresh surface 
6 repeats Candidate 1, then shift aside 
6 repeats Candidate 2, then shift aside 
6 repeats SRTT, then shift aside 
3.2.2. Order of testing: 
 If only one candidate tyre is to be evaluated, the order of testing shall be: 
R1 - T - R2 
Where:  
R1 is the initial test of the SRTT, R2 is the repeat test of the SRTT and 
T is the test of the candidate tyre to be evaluated.  
 A maximum of two candidate tyres may be tested before repeating 
the SRTT test, for example:  
 R1 - T1 - T2 - R2. 
3.2.3. The comparative tests of SRTT and candidate tyres shall be repeated on two 
different days. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
98  3.3. Test procedure 
3.3.1. Drive the vehicle at a speed not lower than 28 km/h. 
3.3.2. When the measuring zone has been reached, the vehicle gear is set into 
neutral, the brake pedal is depressed sharply by a constant force sufficient to 
cause operation of the ABS on all wheels of the vehicle and to result in stabl e 
deceleration of the vehicle and held down until the speed is lower than 
8 km/h. 
3.3.3. The mean fully developed deceleration between 25 km/h and 10 km/h shall 
be computed from time, distance, speed, or acceleration measurements. 
3.4. Data evaluation and presentation of results 
3.4.1. Parameters to be reported 
3.4.1.1. For each tyre and each braking test, the mean and standard deviation of the 
mfdd shall be computed and reported. 
 The coefficient of variation CV of a tyre braking test shall be computed as: 
  
 tyre Meantyre dev StdtyreCV.
 
3.4.1.2 Weighted averages of two successive tests of the SRTT shall be computed 
taking into account the number of candidate tyres in between: 
 In the case of the order of testing R1 - T - R2, the weighted average of the 
SRTT to be used in the comparison of the performance of the candidate tyre 
shall be taken to be: 
wa(SRTT) = (R 1 + R 2)/2 
Where:  
R1 is the mean fully developed deceleration  for the first test of the 
SRTT and R2 is the mean mfdd for the second test of the SRTT.  
 In the case of the order of  testing R1 – T1 – T2 – R2, the weighted 
average (wa) of the SRTT to be used in the comparison of the 
performance of the candidate tyre shall be taken to be:  
 wa (SRTT) = 2/3 R 1 + 1/3 R 2 for comparison with the candidate 
tyre T1; and:  
 wa (SRTT) = 1/3 R 1 + 2/3 R 2 for comparison with the candidate 
tyre T2 . 
3.4.1.3. The snow grip index (SG) in per cent of a candidate tyre shall be computed 
as: 
 
) SRTT ( wa) candidate ( Mean) candidate ( Index Grip Snow  
3.4.2. Statistical validations 
 The sets of repeats of measured or computed mfdd for each tyre should be 
examined for normality, drift, eventual outliers. 
 The consistency of the means and standard-deviations of successive braking 
tests of SRTT should be examined. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 99  The means of two successive SRTT braking tests shall not differ by more 
than 5 per cent. 
 The coefficient of variation of any braking test shall be less than 6 per cent. 
 If those conditions are not met, tests shall be performed again after re-
grooming the test course. 
3.4.3. In the case where the candidate tyres cannot be fitted to the same vehicle as 
the SRTT, for example, due to tyre size, inability to achieve required loading 
and so on, comparison shall be made using intermediate tyres, hereinafter 
referred to as "control tyres", and two different vehicles. One vehicle shall be 
capable of being fitted with the SRTT and the control tyre and the other 
vehicle shall be capable of being fitted with the control tyre and the 
candidate tyre. 
3.4.3.1 The snow grip index of the control tyre relative to the SRTT (SG1) and of 
the candidate tyre relative to the control tyre (SG2) shall be established using 
the procedure in paragraphs 3.1. to 3.4.2. above. 
The snow grip index of the candidate tyre relative to the SRTT shall be the 
product of the two resulting snow grip indices that is SG1 x SG2. 
3.4.3.2. The ambient conditions shall be comparable. All tests shall be completed 
within the same day. 
3.4.3.3. The same set of control tyres shall be used for comparison with the SRTT 
and with the candidate tyre and shall be fitted in the same wheel positions. 
3.4.3.4. Control tyres that have been used for testing shall subsequently be stored 
under the same conditions as required for the SRTT. 
3.4.3.5. The SRTT and control tyres shall be discarded if there is irregular wear or 
damage or when the performance appears to have been deteriorated. 
4. Acceleration method for Class C3 tyres 
4.1. According to the definition of C3 tyres reported into paragraph 2.4.3. above , 
the additional classification for the purpose of this test method only applies: 
(a)  C3 Narrow (C3N), when the C3 tyre nominal section width is lower 
than 285 mm 
(b) C3Wide (C3W), when the C3 tyre nominal section width is greater or 
equal to 285 mm 
4.2. Methods for measuring snow grip index 
Snow performance is based on a test method by which the average 
acceleration in an acceleration test, of a candidate tyre is compared to that of 
a standard reference tyre. 
The relative performance shall be indicated by a snow grip index (SG). 
When tested in accordance with the acceleration test in paragraph 4.7. below , 
the average acceleration of a candidate snow tyre shall be at least 1.25 
compared to one of the two equivalent SRTTs – ASTM F 2870 and  
ASTM F 2871. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
100  4.3. Measuring equipment 
4.3.1. A sensor suitable for measuring speed and distance covered on snow/ice 
surface between two speeds must be used. 
To measure vehicle speed, a fifth wheel or non-contact speed-measuring 
system (including radar, GPS …) shall be used.  
4.3.2. The following tolerances shall be respected: 
(a) For speed measurements:   ±1 per cent (km/h) or 0.5 km/h whichever 
is greater. 
(b) For distance measurements:  ±1 x 10-1 m 
4.3.3. A display of the measured speed or the difference between the measured 
speed and the reference speed for the test is recommended inside the vehicle 
so that the driver can adjust the speed of the vehicle. 
4.3.4. For Acceleration test covered in paragraph 4.7. below, a display of the slip 
ratio of the driven tyres is recommended inside the vehicle and shall be used 
in the particular case of paragraph 4.7.2.1.1. below. 
The slip ratio is calculated by  
100Speed VehicleSpeed Vehicle Speed Wheel% Ratio Slip 
 
 
 (a) Vehicle speed is measured as defined in 4.3.1. above (m/s) 
(b) Wheel speed is calculated on a tyre of the driven axle by measuring 
its angular velocity and its loaded diameter  
speed angular diameter loadedπ Speed Wheel   
 
Where, π = 3.1416 (m/360deg), the loaded diameter (m) and the angular 
speed (revolution per second = 360 deg/sec). 
4.3.5.  A data acquisition system can be used for storing the measurements. 
4.4. General conditions 
4.4.1. Test course 
The test shall be done on a flat test surface of sufficient length and width, 
with a maximum 2 per cent gradient, covered with packed snow.  
4.4.1.1 The snow surface shall be composed of a hard packed snow base at least 
3 cm thick and a surface layer of medium packed and prepared snow about 
2 cm thick. 
4.4.1.2. The snow compaction index measured with a CTI penetrometer shall be 
between 80 and 90. Refer to the appendix of ASTM F1805 for additional 
details on measuring method. 
4.4.1.3. The air temperature, measured about one meter above the ground, shall be 
between -2 °C and  -15 °C; the snow temperature, measured at a depth of 
about one centimeter, shall be between  -4 °C and  -15 °C. 
Air temperature shall not vary more than 10 deg C during the test.  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 101 4.5. Tyres preparation and break- in 
4.5.1. Fit the test tyres on rims as per ISO 4209-1 using conventional mounting 
methods. Ensure proper bead seating by the use of a suitable lubricant. 
Excessive use of lubricant should be avoided to prevent slipping of the tyr e 
on the wheel rim. 
4.5.2. The tyres should be "broken-in" prior to testing to remove spew, compound 
nodules or flashes resulting from moulding process.  
4.5.3. Tyres shall be conditioned at the outdoor ambient temperature at least two 
hours before their mounting for tests.  
They should be placed such that they all have the same ambient temperature 
prior to testing and be shielded from the sun to avoid excessive heating by 
solar radiation. 
The tyre surface in contact with snow shall be cleaned before performing a 
test. 
Tyre pressures shall then be adjusted to the values specified for the test. 
4.6. Testing sequence 
If only one candidate tyre is to be evaluated, the order of testing shall be: 
R1, T, R2 
Where: 
R1 is the initial test of the SRTT, R2 is the repeat test of the SRTT and T is 
the test of the candidate tyre to be evaluated. 
A maximum of 3 candidate tyres may be tested before repeating the SRTT 
test, for example: R1, T1, T2, T3, R2. 
Recommendations are that the zones where acceleration is fully applied shall 
not overlap without reworking and when a new set of tyres is tested; 
The runs are performed after shifting the vehicle trajectory in order not to 
accelerate on the tracks of the previous tyre; when it is no longer possible not 
to overlap full acceleration zones, the test course should be re-groomed. 
4.7. Acceleration on snow test procedure for snow grip index of Class es C3N and 
C3W 
4.7.1. Principle 
The test method covers a procedure for measuring the snow grip performance 
of commercial vehicle tyres during acceleration, using a commercial vehicle 
having a Traction Control System (TCS, ASR, etc.). 
Starting with a defined initial speed, the full throttle is applied to activate the 
traction control system, the average acceleration is calculated between two 
defined speeds. 
4.7.2. Vehicle 
4.7.2.1. The test shall be conducted with a standard 2 axle commercial vehicle in 
good running order with: E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
102  (a) Low rear axle weight and an engine powerful enough to maintain the 
average percentage of slip during the test as required in paragraphs 
4.7.5.1. and 4.7.5.2.1. below; 
(b) A manual gearbox (automatic gearbox with manual shift allowed) 
having a gear ratio covering the speed range of at least 19 km/h 
between 4 km/h and 30 km/h; 
(c) Differential lock on driven axle is recommended to improve 
repeatability; 
(d) A standard commercial system controlling/limiting the slip of the 
driving axle during acceleration (Traction Control, ASR, TCS, etc.). 
4.7.2.1.1. In the particular case where a standard commercial vehicle equipped with a 
traction control system is not available, a vehicle without Traction 
Control/ASR/TCS is permitted provided the vehicle is fitted with a system to 
display the percentage slip as stated in paragraph 4.3.4. of this annex and a 
mandatory differential lock on the driven axle used in accordance with 
operating procedure 4.7.5.2.1. below.  If a differential lock is available it 
shall be used; if the differential lock, however, is not available, the average 
slip ratio should be measured on the left and right driven wheel. 
4.7.2.2. The permitted modifications are: 
(a) Those allowing to increase the number of tyre sizes capable to be 
mounted on the vehicle; 
(b) Those permitting to install an automatic activation of the acceleration 
and the measurements. 
Any other modification of the acceleration system is prohibited. 
4.7.3. Vehicle fitting 
The rear driven axle may be indifferently fitted with 2 or 4 test tyres if 
respecting the loading by tyre.  
The front steer non driven axle is equipped with 2 tyres having a size suitable 
for the axle load. These 2 front tyres could be maintained along the test.  
4.7.4. Load and inflation pressure 
4.7.4.1. The static load on each rear driven test tyres must be between 20 per cent and 
55 per cent of the tested tyre load capacity written on the sidewall. 
The vehicle front steer total static axle load should be between 60 per cent 
and 160 per cent of the driven rear total axle load.  
The static tyre load on the same driven axle should not differ by more than 
10 per cent. 
4.7.4.2. The driven tyres inflation pressure shall be 70 per cent of the one written on 
the sidewall. 
The steer tyres are inflated at nominal sidewall pressure. 
If the pressure is not marked on the sidewall, refer to the specified pressure in 
applicable tyre standards manuals corresponding to maximum load capacity. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 103 4.7.5. Testing runs 
4.7.5.1. Mount first the set of reference tyres on the vehicle and when on the testing 
area. 
Drive the vehicle at a constant speed between 4 km/h and 11 km/h and the 
gear ratio capable of covering the speed range of at least 19 km/h for the 
complete test programme (e.g. R- T1-T2-T3-R). 
The recommended gear ratio selected is 3rd or 4th and shall give a minimum 
10 per cent average slip ratio in the measured range of speed. 
4.7.5.2. In case of traction control system equipped vehicles (already switched "on" 
before the run) apply full throttle until the vehicle has reached the final speed. 
Final speed = Initial speed + 15 km/h 
No rearward restraining force shall be applied to the test vehicle.  
4.7.5.2.1. In the particular case of paragraph 4.7.2.1.1. of this annex where a standard 
commercial vehicle equipped with a traction control system is not available, 
the driver shall manually maintain the average slip ratio between 10 and 40 
per cent (controlled slip procedure in place of the full slip) within the 
prescribed range of speeds. If a differential lock is not available, the averaged 
slip ratio difference between the left and right driven wheel shall not be 
higher than 8 per cent for each run. All the tyres and runs in the test session 
are performed with controlled slip procedure. 
4.7.5.3. Measure the distance between the initial speed and the final speed. 
4.7.5.4. For every candidate tyre and the standard reference tyre, the acceleration test 
runs shall be repeated a minimum of 6 times and the coefficients of variation 
(standard deviation/average*100) calculated for minimum 6 valid runs on the 
distance shall be lower than or equal to 6 per cent. 
4.7.5.5. In case of traction control system equipped vehicle, the average slip ratio 
shall be in the range from 10 per cent to 40 per cent (calculated as per 
paragraph 4.3.4. of this annex). 
4.7.5.6. Apply testing sequence as defined in paragraph 4.6. above. 
4.8. Processing of measurement results 
4.8.1. Calculation of the average acceleration AA 
Each time the measurement is repeated, the average acceleration AA (m ∙ s-2) 
is calculated by  
D 2S SAA2
i2
f
 
Where D (m) is the distance covered between the initial speed S i (m.s-1) and 
the final speed S f (m.s-1).  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
104  4.8.2. Validation of results 
For the candidate tyres: 
The coefficient of variation of the average acceleration is calculated for all the 
candidate tyres. If one coefficient of variation is greater than 6 per cent, 
discard the data for this candidate tyre and repeat the test. 
100averagestdevvariationoft coef f icien  
 
For the reference tyre: 
If the coefficient of variation of the average acceleration "AA" for each group 
of min 6 runs of the reference tyre is higher than 6 per cent, discard all data 
and repeat the test for all tyres (the candidate tyres and the reference tyre). 
In addition and in order to take in account possible test evolution, the 
coefficient of validation is calculated on the basis of the average values of 
any two consecutive groups of min 6 runs of the reference tyre. If the 
coefficient of validation is greater than 6 per cent, discard the data for all the 
candidate tyres and repeat the test. 
100Average1Average1 Average2validationoft coef f icien 
 
4.8.3. Calculation of the "average AA" 
If R 1 is the average of the "AA" values in the first test of the reference tyre, 
R2 is the average of the "AA" values in the second test of the reference tyre, 
the following operations are performed, according to Table 1: 
Table 1 
If the number of sets of candidate 
tyres between two successive runs 
of the reference tyre is:  and the set of candidate tyres to be 
qualified is:  then "Ra" is calculated by applying 
the following:  
 1     R - T1 – R T1 Ra = 1/2 (R 1 + R 2) 
 2     R - T1 – T2 – R T1 
T2 Ra = 2/3 R 1 + 1/3 R 2 
Ra = 1/3 R 1 + 2/3 R 2 
 3    R - T1 – T2 - T3 – R T1 
T2 
T3 Ra = 3/4 R1 + 1/4 R 2 
Ra = 1/2 (R 1 + R 2) 
Ra = 1/4 Ry + 3/4 R y 
 
"Ta" (a = 1, 2, …) is the average of the AA values for a test of a candidate 
tyre. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
 105 4.8.4 "AFC" Calculation (Acceleration Force Coefficient)  
 Also called AFC Acceleration Force Coefficient 
Calculation on of AFC(T a) and AFC(R a) as defined in Table 2 : 
Table 2 
 The acceleration force coefficient 
"AFC" is:  
Reference tyre  AFC(R) = 
gRa   
Candidate tyre  AFC(T) =  
gTa  
Ra and Ta are in m/s²  
"g"= gravity acceleration (rounded to 9.81 m/s2)  
4.8.5. Calculation of the relative snow grip index of the tyre 
The snow grip index represents the relative performance of the candidate tyre 
compared to the reference tyre.  
AFC(R)AFC(T)Index Grip Snow
 
4.8.6. Calculation of the slip ratio 
The slip ratio can be calculated as the average of slip ratio as mentioned in 
paragraph 4.3.4. of this annex or by comparing the average distance referred 
to in paragraph 4.7.5.3. of this annex of the minimum 6 runs to the distance 
of a run done without slip (very low acceleration) 
100distance  slip  Nodistance  slip  No distance  Average% Ratio Slip 
 
 
No slip distance means the wheel distance calculated on a run done with a 
constant speed or a continuous low acceleration. 
4.9. Snow grip performance comparison between a candidate tyre and a reference 
tyre using a control tyre 
4.9.1. Scope 
When the candidate tyre size is significantly different from the reference tyre 
a direct comparison on the same vehicle may be not possible. This is an 
approach using an intermediate tyre, hereinafter called the control tyre. 
4.9.2. Principle of the approach 
The principle lies upon the use of a control tyre and 2 different vehicles for 
the assessment of a candidate tyre in comparison with a reference tyre. 
One vehicle can fit the reference tyre and the control tyre, the other the 
control tyre and the candidate tyre. All conditions are in conformity with 
paragraph 4.7. above . E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 
 
106  The first assessment is a comparison between the control tyre and the 
reference tyre. The result (snow Grip Index 1) is the relative efficiency of the 
control tyre compared to the reference tyre. 
The second assessment is a comparison between the candidate tyre and the 
control tyre. The result (snow grip index 2) is the relative efficiency of the 
candidate tyre compared to the control tyre. 
The second assessment is done on the same track as the first one. The air 
temperature must be in the range of +/- 5 deg C of the temperature of the first 
assessment. The control tyre set is the same set as the set used for the first 
assessment. 
The snow grip performance index of the candidate tyre compared to the 
reference tyre is deduced by multiplying the relative efficiencies calculated 
above: 
SG2 SG1 Index Grip Snow 
 
4.9.3. Selection of a set of tyres as a control tyre set 
A control tyre set is a group of identical tyres made in the same factory 
during one week period. 
4.10. Storage and preservation 
Before the first assessment (control tyre / reference tyre), normal storage 
conditions can be used. It is necessary that all the tyres of a control tyre set 
have been stored in the same conditions. 
As soon as the control tyre set has been assessed in comparison with the 
reference tyre, specific storage conditions shall be applied for control tyres 
replacement. 
When irregular wear or damage results from tests, or when wear influences 
the test results, the use of the tyre shall be discontinued. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 – Appendix 1 
 
 
 107 Annex 7 - Appendix 1 
  Pictogram definition of "Alpine Symbol" 
 
 
 
 
 
 
Minimum 15 mm base and 15 mm height. 
Above drawing not to scale. 
E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 - Appendix 2 
 
108 Annex 7 - Appendix 2 
  Test reports and test data for C1 and C2 tyres 
Part 1 - Report 
1. Type Approval Authority or Technical Service:  ...............................................   
2. Name and address of applicant: .........................................................................   
3. Test report No.:  ................................................................................................ .  
4. Manufacturer and brand name or trade description:  .........................................   
5. Tyre class:  .........................................................................................................   
6. Category of use:  ................................................................................................   
7. Snow index relative to SRTT according to paragraph 6.4.1.1. 
7.1. Test procedure and SRTT used  .........................................................................   
8. Comments (if any):  ...........................................................................................   
9. Date:  .................................................................................................................   
10. Signature:  ..........................................................................................................   
Part 2 - Test data 
1. Date of test:  .......................................................................................................  
2. Location of test track:  .......................................................................................   
2.1. Test track characteristics: 
 At start of tests  At end of tests  Specification  
Weather     
Ambient temperature    -2 °C to -15 °C   
Snow temperature    -4 °C to -15 °C   
CTI index    75 to 85  
Other    
3. Test vehicle (make, model and type, year): .......................................................   
4. Test tyre details ..................................................................................................  
4.1. Tyre size designation and service description: ..................................................   
4.2. Tyre brand and trade description: ......................................................................  
4.3. Test tyre data: ....................................................................................................  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 - Appendix 2 
 
 109  SRTT (1st test)  Candidate  Candidate  SRTT (2nd test)  
Tyre dimensions      
Test rim width code      
Tyre loads F/R (kg)      
Load index F/R ( per cent)      
Tyre pressure F/R(kPa)      
 
5. Test results: mean fully developed decelerations (m/s²) / traction coefficient1 
Run number  Specification  SRTT (1st test)  Candidate  Candidate  SRTT (2nd test)  
1      
2      
3      
4      
5      
6      
      
      
      
Mean       
Std-deviation       
CV (%)  < 6 %     
Validation 
SRTT  (SRTT) < 5  
%     
SRTT 
average       
Snow grip 
index   100    
  
 1 Strike out what does not apply. E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 - Appendix 3 
 
110 Annex 7 - Appendix 3 
  Test reports and test data for C3 tyres 
Part 1 - Report 
1. Type Approval Authority or Technical Service:  ...............................................   
2. Name and address of applicant: .........................................................................   
3. Test report No.:  ................................................................................................ .  
4. Manufacturer and brand name or trade description:  .........................................   
5. Tyre class:  .........................................................................................................   
6. Category of use:  ................................................................................................   
7. Snow grip index relative to SRTT according to paragraph 6.4.1.1. 
7.1. Test procedure and SRTT used  .........................................................................   
8. Comments (if any):  ...........................................................................................   
9. Date:  .................................................................................................................   
10. Signature:  ..........................................................................................................   
Part 2 - Test data 
1. Date of test:  .......................................................................................................  
2. Location of test track:  .......................................................................................   
2.1. Test track characteristics: 
 At start of tests  At end of tests  Specification  
Weather     
Ambient temperature    -2 °C to -15 °C 
Snow temperature    -4 °C to -15 °C 
CTI index    80 to 90  
Other     
3. Test vehicle (make, model and type, year): .......................................................   
4. Test tyre details  ................................................................................................ .  
4.1. Tyre size designation and service description:  .................................................   
4.2. Tyre brand and trade description:  .....................................................................  
4.3. Test tyre data:  ...................................................................................................  E/ECE/324/Rev.2/Add.116/Rev.4 
E/ECE/TRANS/505/Rev.2/Add.116/Rev.4 
Annex 7 - Appendix 3 
 
 111  
 SRTT (1st test)  Candidate 1  Candidate 2  Candidate 3  SRTT (2nd test)  
Tyre dimensions       
Test rim width code       
Tyre loads F/R (kg)       
Load index F/R (per 
cent)       
Tyre pressure F/R 
(kPa)       
 
5. Test results: average accelerations (m/s²) 
Run number  Specification  SRTT (1st test)  Candidate 1  Candidate 2  Candidate 3  SRTT (2nd test)  
1       
2       
3       
4       
5       
6       
       
       
       
Mean        
Std-deviation        
Slip ratio ( per 
cent)        
CV (per cent)  ≤ < 6 per cent       
Validation SRTT  (SRTT) ≤ 6 per 
cent      
SRTT average        
Snow index   1.00