Tire Sidewalls - What does it all mean?

Tire sidewalls are a strange creation. Words, acronyms, numbers, letters and symbols adorn the side of each tire. Fortunately, only a small portion of the sidewall is of any relevance when it comes to replacing a tire.

Key information - 195/65 r15 91v

195	The width of the tire in MM
65	The aspect ratio of the tire as a percentage of the width. In this case the sidewall is 45% of 205mm, or 92.25mm
R	Radial construction, as all modern tires are
15	The size of the wheel in inches
91	The load index of the tire in kgs (see table 1)
V	The speed index of the tire (see table 2)

Other useful information

E13	The E-Marking.
XL	Denotes whether the tire is an extra load version
Date of manufacture	The recommend life for a tire is around 6 years (depending on storage conditions.) The first 2 numbers in the date code refer to the week the tire was made, and the 3rd and 4th numbers refer to the year
Rotation direction	If the tire is directional this shows which way the tire should rotate when mounted
Side	If the tire is asymmetric the tire will have 'inside' or 'outside' printed on the tire wall, showing which way round it should be mounted on the car.
US Consumer information	Treadwear, traction and temperature are rated on the side walls. These values can only be used as a comparison for tires within the same brand as there is no common reference between brands.