17" Scion Wheel Tire Pressure

I have the 17" Scion wheels on my 05 Prius package 6. They came with 50 pounds of air in them and I began to run them at 45 pounds for one day, then 40 the next, at present they are set at 34 pounds front and rear and they seem to be riding and wearing just fine.

With the shorter sidewall, when they were at 40 PSI, they seemed to hard and the ride was not as comfortable. At 34 they ride like stock but handle like 17" low profile tires.

Anybody have any other input?