Tuning, Performance and Handling

Tyre Sidewall Markings:

Tyres have several different markings on thier sidewalls, this page explains what they are and what they mean.


Tyre Sizes

Tyre size markings are normally the largest of the marks on the sidewall and are made up of several numbers and letters, below is what these markings mean.

Example tyre size marking: 185/60 R 13 91 T.

Marking Description
185 The tyre section width in millimetres
60 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

There is a 3 digit code on the sidewall of the tyre that indicates the month and year that the tyre was made. For example, 051 would mean the tyre was made in May 2001.


Speed Ratings

All tyres carry a speed symbol in the form of a letter indicating the maximum speed for which the tyre is intended. The table below shows which speed goes with each letter.

symbol 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

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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
65 290
66 300
67 307
68 315
69 325
70 335
71 345
72 355
73 365
74 375
75 387
76 400
77 412
78 425
79 237
80 450
81 462
82 475
83 487
84 500
85 515
86 530
87 545
88 560
89 580
90 600
91 615
92 630
 
Li kg
93 650
94 670
95 690
96 710
97 730
98 750
99 775
100 800
101 825
102 850
103 875
104 900
105 925
106 950
107 975
108 1000
109 1030
110 1060
111 1090
112 1120
113 1150
114 1180
115 1215
116 1250
117 1285
118 1320
119 1360

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