What you just quoted refutes your own comments.
First of all, Light Truck Tires are of different construction and use a different testing regime than passenger car tires, so none of that is applicable to our discussion of the Leaf.
Second, 3 to 5 pounds is a ways from 44 on the Leaf... (FYI, a 4 pound increase had been typical for many years in many car manufacturers recommendations but is no longer usually the case due to the type of construction of modern tires; it was mostly a hold over from bias ply and early radial tires without steel belts and current construction techniques.)
Third, their - or yours, it's unclear which it is - reference to 100% performance ONLY relates to maximum weight carrying ability, nothing else. No modern car comes even close to needing that maximum weight capability so that number is meaningless in our applications. It will, however, increase the insipid hydroplaning speed as that goes up by the square of the tire pressure...
Anyway, do what you want as it won't hurt anything and is not unsafe per se, but you are reading something in to the numbers that is not there, and I wouldn't personally recommend following suit to anyone...
mogur wrote:All my information comes from the DOT and tire manufacturers websites and you can feel free to look it up. I'd like to see some similar supporting evidence for your position, please...
No problem! The information can be found on most manufacturer's sites, however Bridgestone Tire has the following info:
[...]for passenger tires, never exceed the maximum inflation pressure molded on the sidewall. The inflation pressure for light truck tires may exceed that molded on the tire by 10psi. Any recommended front to rear pressure differential should be maintained.
In another section:
For continuous high speed driving, tire pressures should be increased by 3 to 5psi above the normal cold inflation recommended [by the vehicle manufacturer].
While you may get more "comfort" by running your tires at the vehicle manufacturer PSI recommendations, the tires (when properly sized and mounted to wheels) are designed to function with 100% performance at their maximum sidewall pressure.