wondering if this is a good alternative sizing for tires 235/40/18 front and 255/40/18 rear. my rims are 8" wide front and 9" wide rear.

just looking to get a lower profile tire, less mushy feel around the corners..

 

do it! i think it'll look great and fit perfectly... the smaller diameter in the back will effectively raise your final drive ratio too (i.e. *slightly* better acceleration)

 

yeah right now i have 245/40 front and 275/40 rears... i did this only to maintain close to stock diameter but in retrospect, i think i shouldve gotten 235/40 and 255/40 for less mushy feel.

just something i'm looking into for the future.