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:
Precautions for AWD models with automatic transmission
Your vehicle is equipped with the AWD
(All-Wheel Drive) system. In addition, if
your vehicle is an AT model, before driving
your vehicle with the temporary spare tire,
deactivate the AWD capab ...
On-road and off-road driving
- In a rollover crash, an unbelted
person is significantly more
likely to die than a person wearing
a seat belt. You the driver and
all your passengers should fasten
the seatbelts before ...
Tires
Never tow a trailer when the temporary
spare tire is used. The temporary
spare tire is not designed to
sustain the towing load. Use of the
temporary spare tire when towing
can result in ...
