Again, Those figures are correct for the tires on your car. I wouldn't suggest that they are the correct values for a different sized tire. Or even a different tire brand.
If we can agree that a wider 205/45R17 has a larger contact patch than a 195/65R15, then the PSI will very from tire to tire.
If you reduce the square inches, then the pressure should increase to support the same amount of weight. Although in practice, it can actually be the opposite, as lower profile tires are run at higher pressures to protect the rims. |