P-Metric Sized Tires Description
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of GENERAL MOTORS CORP.
Replacement tires should be of the same tire performance criteria (TPC) specification number. This will ensure the same size, the same load range, and the same construction as those originally installed on the vehicle.