not so sure of all p metric tires being 4 ply as some brands of tires carry a p metric standard load & p metric Extra Load & a Lt in the same tire design. The EXTRA LOAD actaully have a more load capacity then the LT by about 30-50 lbs per tire depending on manufacturer
Exam: Lt 235/75R15 Crawler M/T (C)
Tread Depth:
16/32”
Max Load:
1,985 lbs
Outer Diameter:
29.1”
Max PSI:
50 psi
Compared to P Metric
235/75R15 Crawler M/T (P)
Tread Depth:
16/32"
Max Load:
2,028 lbs
Outer Diameter:
29.1”
Max PSI:
44 psi
Several brands have LT,P std load, & P metric XL=Extra Load all in the same design & tread pattern & depth