Hola
I have a question, I have a stock Jk with 17 stock wheels and 265/70/17 Bf Goodrich tires.
I would like to buy 7089 Pro Comp wheels
http://www.quadratec.com/products/92819_23XX_A_PG.htm
what size and Backspacing Do I Have to Choose?
17x8 and 4,50 Backspacing
or
17x9 and 4,75 Backspacing
Many thanks!!!!!

 

either one will work. the 4.5 will push your tires out just a tad further and the 4.75 will bring them in under your flares by a bit. if it were me, i would go with the 4.5 as the extra clearance is nice to have especially if you think you might go bigger in the future.

EDIT: i just realized that the two wheels are of different widths. being this is the case, both wheels will work and will keep your tires about the same position. still, i would recommend the 17x8 - 4.5" back spacing

 

just do exactly as wayoflife says

 

The back spacing depends on which tire you plan on installing. If you're keeping the same set and changing rims the 17x8 should work. In the future, if you're thinking 35's on the JK then you would want the 17x9 rims.

 

not necessarily. while a 9" wheel might be a better fit for a 12.50 wide tire, a narrower wheel is good to have as it will help keep your bead from rolling when aired down. in fact, 8" wide is what i typically recommend doing unless you're planning on getting bead locks.

 

I understand , but if I go for the 17x8 and 4,50 Backspacing instead 17x9 and 4,75 Backspacing I will lose 1 plg (from 9 to 8) and win 0.25.
The 17x9 - 4,75 push the tires out more than 4,5" Am I wrong?

 

the MORE backspacing you have, the more it brings your tires in. the less backspacing you have, the more it pushes them OUT.

 

It really depends on how wide of a tire you wish to go to.

For your 265/70R17 your fine with either wheel. If you plan on going taller/wider (285/70R17, 305/65R17, or 35x12.5R17) you would probably need more backspacing than 4.5 inches.

Also, have you considered going to a 16" rim? Wheels and Tires are less expensive in this size.

You also can go to a 15" rim. Even less expensive but some JK's have had wheel problems (clearance with the brake calipers).

Good Luck!!!

 

this is not correct. "more" back spacing will pull your tires in closer to you frame. factory backspacing is 6.25" and 4.5" will push your tires outward.

 

Many Thanks .
The stock wheels are 17x7,5" , what happens to the height of the tire, in my case ( 185.5 mm - 70% of 265) will descend if I put 17x9" ?