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:
The Inside
The cabin boasts more conventional lines and adult-friendly room, with a
number of welcome changes. The doors now have window frames, yielding a more
substantial thunk when you shut them. The back ...
When the following messages are displayed
If one of the following messages is displayed while operating the CD player,
determine the cause based on the following information. If you cannot clear those
messages, please contact your SUBARU ...
Cargo
We test a standard assortment of grocery bags, golf clubs and luggage in
every car we drive, and there wasn't much — or any, really — room to spare
behind the Tribeca's third row; there's only 8.3 ...
