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Tires

Tire Dimensions: Using Example of: P205/60R15

Rim Width
The width between the flanges of the wheel (the part the bead of the tire touches).

Section Width (measurements in millimeters)
The linear distance between the outside of the sidewalls of an inflated tire without any load on it. This would be the 205 part of the tire P205/60R15 size (this does not include any sidewall decorations).

Section Height (measurements in millimeters)
This is also known as the Aspect Ratio. This is figured on a percentage of the section width. A tire size of P205/60R15 would have a section width of 205 millimeters and a section height of 60 percent of 205 millimeters, or 123mm.

P vs. LT (Imortant for SUV owners to know)
P stands for normal passenger car tire. Most cars have this kind of tire.
LT stands for Light Truck. Check your OEM or owners manual for the spec on the tires used on your SUV. Some larger SUVs are now usings LT tires. These tires have more Plys, or Layers of the fabric that give the tire it's additional strength.