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:
Shopping bag hook
CAUTION
Do not hang items on the shopping bag hook that weigh 11 lbs (5 kg) or more. ...
Adverse safety consequences of overloading on handling and stopping and on
tires
Overloading could affect vehicle
handling, stopping distance, and
vehicle and tire performance in the
following ways. This could lead to
an accident and possibly result in
severe personal in ...
On-road and off-road driving
This vehicle is classified as a utility
vehicle. Utility vehicles have a significantly
higher rollover rate than other types of
vehicles. Your vehicle has a higher ground
clearance and higher ...
