ASPECT RATIO
The aspect ratio is the relationship of the tyre's sidewall height to the tyre's width. In this example, the sidewall height of the tyre is 80% of its width. The lower the ratio, the smaller the sidewall height.
CONSTRUCTION
This is the tyre's internal construction. Almost every tyre on the road has radial construction, which means the cords of the casing plies inside the tyre "radiate" directly across from one side of the tyre to the other. Other constructions used are D, for diagonal construction, and B, for belted.
