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:
Recommended shifting speeds
The best compromise between fuel economy and vehicle performance during normal driving is ensured by shifting up at the speeds listed in the following table.
...
Checking the brake pedal free play
1) 0.08 – 0.18 in (2 – 5 mm)
Stop the engine and firmly depress the brake pedal several times. Lightly pull
the brake pedal up with one finger to check the free play with a force of less than
2 ...
Determining compatibility of tire and vehicle load capacities
The sum of four tires’ maximum load ratings must exceed the maximum loaded vehicle
weight (“GVWR”). In addition, sum of the maximum load ratings of two front tires
and of two rear tires must excee ...