Just like MaineManx & NotaPreppie mentioned.
Factor in some good 'ol physics: PV=nRT. Meaning that when T increases (as happens while driving, or environment, the expansion of the gases happen)
I've filled according to the specifications, and also made all the same.
In short Mazda Specification = best quality drive (fuel, wear and tear, engine strain etc) with room for average load capacity. On decent/good quality roads.
Then again, I've had no complaints for making the pressure all the same, however the roads are littered with bumps and potholes. No issues with this 240Kpa, wet, hot, potholes, braking etc, actually gives me the best fuel efficiency. Highest Fuel range (240Kpa) = 6.5l/100km. Best fuel range (240Kpa) = 5.6l/100km. Both are mixed driving - city and open road.