I have also previously mentioned it here and there.. that our local tire puncture repair shops people fill 45 - 50PSI air pressure in the tires...
Whereas u can easily read clearly written on the both tires that maximum inflation pressure in 40PSI cold.
I think in 4ply tires the Max. inflation pressure is even lesser... 35PSI max.
So due to extra pressure, tires wear out more quickly, do not provide proper road grip, offer a stiff ride and when get punctured more easily just like an over filled balloon blows up more easily...
My bike's manual states 32Psi max. for the rear tire with pillion ridding! And even lower recommended pressure if riding single! and theres about a 5 PSI less pressure for the front tire in both conditions.
I dont know whats the monotony of our people having over pressured tires?