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There are various strange markings and numbers on the side wall of your
tyres. But what do they all mean? Do they tell us anything useful?
Our brief guide covers all the most important markings. Read on to find
out . . .
Sidewall Markings
On the sidewall of a tyre you will find various codes and markings.
The list below aims to simplify the coding system and allow you, the user,
to understand the valuable information imprinted on the sidewall.
Tyre Sizes
Tyre sizes are made up of a number of different numbers and letters.
For example tyre size 175/70 R
13 82 T is made up of the following information:
|
175 |
The
tyre section width in millimetres |
|
70 |
The
aspect ratio in % (the height of the sidewall divided by
the tyre's width) |
|
R |
Denotes
the tyre's construction type - in this case it's a radial |
|
13 |
Rim
diameter in inches |
|
82 |
Load
Index |
|
T |
Speed
Rating |
|
Tyre Age
Tyres carry a three digit age code on the sidewall indicating
the month and year of manufacture. For example 129 means the tyre was manufactured
in December 1999.
Other Markings
M&S - Identifies Mud and Snow tyres
DOT Codes - Coding satisfying the requirements of the US Department
of Transportation contain a mixture of letters and numbers such as DOT
DVDE MTA 129
E-Marks - Tyres for sale in the European Community must carry
an E -Mark in accordance with ECE Reg 30 - eg E4 027550
Speed
Ratings
All
tyres carry a speed symbol in the form of a letter indicating the maximum
speed for which the tyre is intended. You'll find the speed rating on the
outer wall of the tyre, usually near to the manufacturers name. The table
below shows which speed goes with each letter.
|
Speed
symbol |
Maximum
speed km/h |
mph
|
|
N |
140 |
87 |
|
P |
150 |
93 |
|
Q |
160 |
99 |
|
R |
170 |
106 |
|
S |
180 |
112 |
|
T |
190 |
118 |
|
H |
210 |
130 |
|
V |
240 |
149 |
|
W |
270 |
168 |
|
Y |
300 |
186 |
|
|
Speed
category |
Maximum
speed
km/h |
mph
|
|
ZR |
240 |
149 |
|
|
|
and
above |
|
Load Indices
The load-index figure imprinted on the sidewall of the tyre denotes the
maximum load capacity of a tyre when driven at maximum speed. A list
of load indices and maximum weights is give below:
|
Li |
kg |
Li |
kg |
|
65 |
290 |
94 |
670 |
|
66 |
300 |
95 |
690 |
|
67 |
307 |
96 |
710 |
|
68 |
315 |
97 |
730 |
|
69 |
325 |
98 |
750 |
|
70 |
335 |
99 |
775 |
|
71 |
345 |
100 |
800 |
|
72 |
355 |
101 |
825 |
|
73 |
365 |
102 |
850 |
|
74 |
375 |
103 |
875 |
|
75 |
387 |
104 |
900 |
|
76 |
400 |
105 |
925 |
|
77 |
412 |
106 |
950 |
|
78 |
425 |
107 |
975 |
|
79 |
237 |
108 |
1000 |
|
80 |
450 |
109 |
1030 |
|
81 |
462 |
110 |
1060 |
|
82 |
475 |
111 |
1090 |
|
83 |
487 |
112 |
1120 |
|
84 |
500 |
113 |
1150 |
|
85 |
515 |
114 |
1180 |
|
86 |
530 |
115 |
1215 |
|
87 |
545 |
116 |
1250 |
|
88 |
560 |
117 |
1285 |
|
89 |
580 |
118 |
1320 |
|
90 |
600 |
119 |
1360 |
|
91 |
615 |
|
|
|
92 |
630 |
|
|
|
93 |
650 |
|
|
|
See more detail on tyres, how tyres are made, tyre safety, tyre tread patterns, and read our advice on fitting low profile tyres
|