How to read your tyre . . .

Width

This is the width in mm of the tyre from sidewall to sidewall when it's unstressed and you're looking at it head on (or top-down).

Profile Ratio

This is the ratio of the height of the tyre sidewall, expressed as a percentage of the width. In this case, 55% of 205mm is 112.75mm.

Wheel Diameter

This is the diameter in inches of the rim of the wheel that the tyre has been designed to fit on.

Load Index / Speed Rating

The majority of tyres carry coded markings on them, which correspond to their load carrying and maximum speed capabilities.

The load index is a numerical code associated with the maximum load a tyre can carry (see load index table) at the speed indicated by its speed symbol (see Speed Symbol table) under service conditions specified by the tyre manufacturer.

For example, the diagram above shows 91W:

91 = Load Index (91 equates to a weight of approximately 615 kg)
W = Speed symbol (W equates to a speed of approximately 168 mph).

Back to top

Load Index table

Load Index	Load (kg)		Load Index	Load (kg)		Load Index	Load (kg)
65	290		85	515		105	925
66	300		86	530		106	950
67	307		87	545		107	975
68	315		88	560		108	1000
69	325		89	580		109	1030
70	335		90	600		110	1060
71	345		91	615		111	1090
72	355		92	630		112	1120
73	365		93	650		113	1150
74	375		94	670		114	1180
75	387		95	690		115	1215
76	400		96	710		116	1250
77	412		97	730		117	1285
78	425		98	750		118	1320
79	437		99	775		119	1360
80	450		100	800		120	1400
81	462		101	825		121	1450
82	475		102	850		122	1500
83	487		103	875		123	1550
84	500		104	900		124	1600

Back to top

Speed Symbol table

Speed Symbol	Speed (km/h)	Speed (mph)
L	120	75
M	130	81
N	140	87
P	150	93
Q	160	99
R	170	108
S	180	112
T	190	118
U	200	124
H	210	130
V	240	149
W	270	168
Y	300	186

Back to top