Why is the speedo for E67s calculated so different between the two programs? I own both efi, and hpt, if I set the speedo up with hpt efi wants to correct it, if I set it up with efi, hpt wants to correct it? who is correct?

Hpt only lets you edit VSS tire revs per, and VSS pule per, and final drive gear ratio, and final gear error

Efi lets you edit VSS tire revs per, and VSS pule per, and final drive gear ratio, and final gear error, plus driven and non driven wheel rolling circumference, tire size correction?

Hpt really seems to mess up the tire size correction? Shouldn't that be zero if its calculated correctly? maybe that's why we cant view that in hpt editor?? Or maybe hpt doesn't let us view it because changing t doesn't matter? All I know is if I set up the speedo with hpt, and save it, then open with efi live it wants to correct what hpt did? Efi and sometimes hpt want to correct factory speedo settings too?? I don't get it.