Becasue its not the same dia.
Staggered as in width has zero to do with anything. you could run a steam roller drum for rear tires… as long as the outside dia is the same as the fronts.
255/40 R18:
DIA: 26.0
265/35 r18:
DIA: 25.3
put it this way, math works out that the 26" tire will roll 775 times in a mile, where as the 25.3" tire will roll that same mile 797 times.
so for every mile your center differential will hate life 22 times every mile, if it even made it a mile. :rofl
ANNND furthermore, a 255 VS a 265 is all of about 3/8" wider! lol thats big leap in foot print there! :rofl
ALSO keep in mind, you retards, actual sizes (dia and widths) vary greatly between manufactures and even models within the same manufacturer. So mix and matching shit gets very difficult.