On the sidewall of the tire, there is a tire size listed. Next to this, there is listed two very important things:
1. Load index
2. Speed rating
From TireRack:Over the years, tire speed rating symbols have been marked on tires in any of three ways shown in the following examples:
225/50SR16..... 225/50SR16 89S...... or 225/50R16 89S
Each of these was an acceptable method of identifying speed ratings.
READ THIS LINK FOR BETTER UNDERSTANDINGhttp://
www.tirerack.com/tires/...d.jsp