P Metric
With the P-Metric system, Section Width is measured in millimeters.
To convert millimeters into inches, divide by 25.4. The Aspect Ratio (Section Height divided by Section Width) helps provide more dimensional information about the tire size.
Example:

(1) P = Certain tire type used on light duty vehicles such as passenger
cars
(2) Section Width in millimeters
(3) Aspect Ratio (= section height 7 section width).
(4) R = Radial Construction
(5) Rim diameter in inches
See also:
Warning and indicator lights
...
Tire size
Your vehicle comes equipped with P-Metric tire size. It is important to understand
the sizing system in selecting the proper tire for your vehicles. Here is a brief
review of the tire sizing syste ...
Before driving your vehicle
Before entering the vehicle, remove any snow or ice from your shoes because that
could make the pedals slippery and driving dangerous.
While warming up the vehicle before driving, check that the ac ...
