3 bar ~= 43 PSI
Back in the days when I was a Prius owner active on PriusForum, many owners ran their vehicles at 40+ PSI to increase PSI, and it worked.
As long as you keep it below MaxPSI of the tires, it should be fine.
Just need to watch if the tires wear the center more.
With HRR (high rolling resistance) tires, this is not a problem due to thick side wall.
For other tire, something to keep an eye on regularly.