ANNEX IU.K.TESTING, GRADING AND MEASUREMENT OF TYRE PARAMETERS
Part A: Fuel efficiency classes and rolling resistance coefficientU.K.
The fuel efficiency class shall be determined and illustrated on the tyre label on the basis of the rolling resistance coefficient (RRC in N/kN) according to the ‘A’ to ‘E’ scale specified in the table below and measured in accordance with Annex 6 to UNECE Regulation No 117 and aligned in accordance with the laboratory alignment procedure set out in Annex V.
If a tyre type belongs to more than one tyre class (e.g. C1 and C2), the grading scale used to determine the fuel efficiency class of that tyre type shall be that which is applicable to the highest tyre class (e.g. C2, not C1).
| C1 tyres | C2 tyres | C3 tyres | |
|---|---|---|---|
| Fuel efficiency class | RRC in N/kN | RRC in N/kN | RRC in N/kN |
| A | RRC ≤ 6,5 | RRC ≤ 5,5 | RRC ≤ 4,0 |
| B | 6,6 ≤ RRC ≤ 7,7 | 5,6 ≤ RRC ≤ 6,7 | 4,1 ≤ RRC ≤ 5,0 |
| C | 7,8 ≤ RRC ≤ 9,0 | 6,8 ≤ RRC ≤ 8,0 | 5,1 ≤ RRC ≤ 6,0 |
| D | 9,1 ≤ RRC ≤ 10,5 | 8,1 ≤ RRC ≤ 9,0 | 6,1 ≤ RRC ≤ 7,0 |
| E | RRC ≥ 10,6 | RRC ≥ 9,1 | RRC ≥ 7,1 |
Part B: Wet grip classesU.K.
1.The wet grip class shall be determined and illustrated on the tyre label on the basis of the wet grip index (G) according to the ‘A’ to ‘E’ scale specified in the table below, calculated in accordance with point 2 and measured in accordance with Annex 5 to UNECE Regulation No 117.U.K.
2.Calculation of wet grip index (G)U.K.
G = G(T)-0,03
where:
G(T) = wet grip index of the candidate tyre as measured in one test cycle
| C1 tyres | C2 tyres | C3 tyres | |
|---|---|---|---|
| Wet grip class | G | G | G |
| A | 1,55 ≤ G | 1,40 ≤ G | 1,25 ≤ G |
| B | 1,40 ≤ G ≤ 1,54 | 1,25 ≤ G ≤ 1,39 | 1,10 ≤ G ≤ 1,24 |
| C | 1,25 ≤ G ≤ 1,39 | 1,10 ≤ G ≤ 1,24 | 0,95 ≤ G ≤ 1,09 |
| D | 1,10 ≤ G ≤ 1,24 | 0,95 ≤ G ≤ 1,09 | 0,80 ≤ G ≤ 0,94 |
| E | G ≤ 1,09 | G ≤ 0,94 | G ≤ 0,79 |
Part C: External rolling noise classes and measured valueU.K.
The external rolling noise measured value (N, in dB(A)) shall be declared in decibels and calculated in accordance with Annex 3 to UNECE Regulation No 117.
The external rolling noise class shall be determined and illustrated on the tyre label on the basis of the limit values (LV) set out in Part C of Annex II to Regulation (EC) No 661/2009 as follows:
| N ≤ LV – 3 | LV – 3 < N ≤ LV | N > LV |
 |  |  |
Part D: Snow gripU.K.
The snow grip performance shall be tested in accordance with Annex 7 to UNECE Regulation No 117.
A tyre which satisfies the minimum snow grip index values set out in UNECE Regulation No 117 shall be classified as a tyre for use in severe snow conditions and the following pictogram shall be included on the tyre label.
Part E: Ice gripU.K.
The ice grip performance shall be tested in accordance with reliable, accurate and reproducible methods, including, where appropriate, international standards, which take into account the generally recognised state of the art.
The tyre label of a tyre which satisfies the relevant minimum ice grip index values shall include the following pictogram.
