1. Understanding a Tire Label A Typical Label P 195/60 V R 15 What Does Each Part Mean?

2. Understanding a Tire Label P 195/60 V R 15 Tire Type P P – Passenger T T – Temporary LT – Light Truck C C- Commercial

3. Understanding a Tire Label P 195/60 V R 15 Section Width In Millimeters (mm) Can Range From 145-315

4. Understanding a Tire Label P 195/60 V R 15 Aspect Ratio Equals Section Height divided by Section Width multiplied by 100% (SH/SWx100%)

5. Understanding a Tire Label P 195/60 V R 15 (Optional) Speed Rating Can range from B (31 mph) to Z (over 149 mph)

6. Understanding a Tire Label P 195/60 V R 15 Construction Type R R – Radial B B – Bias Belted D D – Diagonal

7. Understanding a Tire Label P 195/60 V R 15 Rim Diameter

10. Calculating Tire Diameters If we an calculate the section height and convert it to inches then all we need to do is simply double the section height and add it to the rim diameter.

11. Since the Aspect Ratio is equal to the Section Height / Section Width * 100% AR = SH/SW*100 Then SH = (AR*SW)/100)

12. P 195/60 V R 15 SH = (AR*SW)/100 SH = 60*195 mm/100 SH = 117 mm ******************************** Since 1 inch =25.4 mm 117 mm = 4.6 inches 25.4 mm/in. therefore the total height of the tire is 2 * 4.6 in + 15 in = 24.2 inches

13. These steps can be combined into one formula which looks like this: 2 * (AR * SW) Tire Diameter = ------------------------- + Rim Dia. (100 * 25.4mm) (AR * SW) Tire Diameter = ------------------------- + Rim Dia. 1,270