Hi, i am planning on changing all 4 of my tires soon. I have Advan RGII 17x7.5 front and 17x8.5 rear. As of right now i run on 225 front and 255 rear...but just wondering if i can go a little bigger on the back like 265-40-17 or 275-40-17...or should i just stay at 255 on the rear? thanks.

 

not sure if it will work or not on yours, but i'm running 275 in the rears on le28s 17 +63

you'll get some more technical answer in the tire forum by the way

 

You would not want to run anything that large on an 8.5 inch wheel. Don't think that a wider tire in the rear is always better. Too large of a stagger can throw off the balance of the car. Too wide of a tire in back might also cause fitment issues, ABS issues, speedo calibration issues, and others.
Now for the empirical data: 265/40R17 has suggested rim widths 9-10.5 in, and diameter difference +2.49% (a significant, but not detrimental, variance). 275-40-17 has suggested widths of 9 - 11 in, and diameter difference of +3.71% (inadvisable variance).
Both tires would bulge, be unsafe, and look just silly to me. Stick with 255 max!

 

I really would not got bigger than the 255/40R17 on the rear matched with the 225/45R17 on the front. They will fit the wheels and keep the same kind of stagger as stock.
If I can help just let me know.

 

what they said ^

not to mention.. a 255 on a rgII is not so easy. camber, fender roll is most likely going to be required.

 

whats the offsets? +55 in the rear right?