The letter "P" at the beginning of the "Tire Size" tells us the tire is a P Metric tire, referring to tires made to certain standards within the United States, intended for Passenger vehicles. If a tire size has no letters at the beginning, this indicates a Euro metric tire. P Metric and Euro Metric tires
Jan 03, 2006· For load range "B" tires, ETRTO standards specify the load index rating at an inflation pressure of 36 psi , while P Metric standards measure the load capacity at an inflation pressure of 35 psi . The two standards vary slightly with the capacity required for different inflation pressures.Estimated Reading Time: 8 mins
Tread Depth by the Numbers. The tire industry standard for tread depth in the United States is measured in one thirty second of an inch increments .