READ A TIRE

Along with the Manufacturer’s name and the name of the tire, there will be a set of numbers and letters that relate to the size of the tire, like this: 205/65R15

205 is the width of the tire in millimeters

65 is the aspect ratio of tire profile (explained below)

R means it is radial construction

15 is diameter of the wheel rim in inches

A tires profile relates to the depth of the sidewall (the wall at the side of the tire). Higher performance vehicles are usually fitted with tires that have narrow sidewalls, or lower profiles. The profile is expressed as a % of the tire’s width. For example our 205/65R15 tire has a profile or sidewall that is 65% of the 205mm (width). A low profile tire is generally 45 or below and down to as little as 30 in the ultra high performance segment (such as the Wide Oval). The benefit of low profile tires is that they give you greater control and better handling when cornering, but the trade off can be a slightly more bumpy ride. Also, going to a lower profile on the same size wheels alters the speedometer reading so you’ll need to increase the tire and wheel diameter size.

All tires carry a speed symbol in the form of a letter indicating the maximum speed for which the tire is intended. 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