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:
PTY (Program type) group tuning (only FM reception)
Press the “PTY/CAT” button to change to the PTY selection mode. At this time,
the PTY group that you are currently listening to will be displayed for 10 seconds.
In PTY selection mode, “PTY SEL” ...
Non-turbo models
Non-turbo models
1) Power steering fluid reservoir
2) Manual transmission oil level gauge (MT) or Differential gear oil level gauge
(AT)
3) Clutch fluid reservoir
4) Automatic transmission ...
Construction type
Applicable construction of this tire.
For example, “TUBELESS STEEL
BELTED RADIAL” ...
