Ive read thru a number of post and thou i can find alot of post about the difference in backspacing on the front and rear of the 16", i cant find why there is a difference, i dont realy care for the 16" on the 91 rs im picking up and plan to switch them and ive seen alot of people say you can just go 4.5 backspacing all the way around like the 15's were, but why did the put 5 1/8s on the back to begin with?

 

A narrower rear track width promotes handling by "encouraging" the rear of a vehicle to track behind the front of a vehicle & not slide out in emergency avoidance driving.

 

what he said^

you can use 4.5" of bs with a 8" wheel no problems on all 4 corners

 

Alright makes sense,so i take it if you measure it the rear will actually come out 1 1/4 inch smaller than the front tire width?