A 28" tire @ 4.10 will have about the same effective torque as a 31" @ 4.56 and a 33" @ 4.88
The larger diameter tire negates the higher ratio R&P.
Take a look at 4.88 33" 5th and 4.56 31" 5th RPM. They are about the same. The 4.88 torque numbers look better, but really aren't because you lose some torque multiplication due to the larger diameter.
Hmmm... the torque numbers are different because of multiplication.
Gnarls.
