Tyre Terminology

Tyre Sizes

Your tyre size can be found on the sidewall. Sizes are made up of many different combinations including various numbers and letters.

For example,

195/65R15 91H

195             Represents the tyre section width in millimetres (width of treaded area)

65                 Represents the aspect ratio (sidewall height). As a percentage of the tyre width

R            Denotes the tyre’s construction type. In this case, a RADIAL

15                 The diameter of the wheel in inches

91           The load index

H                   The speed rating

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Load Index

The load index is a numerical code associated with the maximum load a tyre can carry at the speed indicated by its speed symbol .

You will find your load rating as shown:-

195/65R15 91 H

Load Index	Load kg	Load Index	Load kg	Load Index	Load kg	Load Index	Load kg	Load Index	Load kg	Load Index	Load kg
60	250	71	345	82	475	93	650	104	900	115	1215
61	257	72	355	83	487	94	670	105	925	116	1250
62	265	73	365	84	500	95	390	106	950	117	1285
63	272	74	375	85	515	96	710	107	975	118	1320
64	280	75	387	86	530	97	730	108	1000	119	1360
65	290	76	400	87	545	98	750	109	1030	120	1400
66	300	77	412	88	560	99	775	110	1060	121	1450
67	307	78	425	89	580	100	800	111	1090	122	1500
68	315	79	437	90	600	101	825	112	1120	123	1550
69	325	80	450	91	615	102	850	113	1150	124	1600
70	335	81	462	92	630	103	875	114	1180	125	1650

*In order to establish the correct tyre, your vehicles' maximum weight needs to be divided by the total number of road wheels in use.

For Example:-An '07 Citroen C5 2.0 Hdi 16V has a maximum laden weight of 2040kg*

2040kg divided by 4 (number of road wheels) = 504.5kg Therefore, each tyre must have a load index of 85 or over.

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Speed Rating

The speed rating (denoted by a letter) represents the maximum permissible speed for which the tyre is rated.

You will find your speed rating as shown:-

195/65R15 91 H

N Rated	87mph
P	93mph
Q	99mph
R	106mph
S	112mph
T	118mph
U	124mph
H	130mph
V	149mph
Z	150+mph
W	168mph
Y	186mph