Jeep Garage  - Jeep Forum banner
1 - 6 of 6 Posts

·
Registered
(2) 2015 Grand Chero
Joined
·
3 Posts
Discussion Starter · #1 ·
Does anyone know if a 20x10 -24 offset rim running a 275-55-20 tire will work on a 2015 GC? I know nothing about offsets.
 

·
Registered
Joined
·
30 Posts
Speaking for experience, you won’t be able to run that set up. I had a 2inch eibach lift and I was trying to run the same set up but -19. It rubbed like hell, I had to exchange the rims for 0 offset. Lol. I’ve seen people run it before but you have to be prepared to do some trimming
 

·
Registered
Joined
·
299 Posts
The closer you get to zero (and into positive) from the negative side the more the wheel will poke out.

Stock rims are -54 or so, so when off roading the tire will tuck into the well. A -34 will push the rim out of the well somewhat and is probably as low as you want to go w/o much rub on the fender. A 0 or into positive will poke out of the well farther and you might start rubbing even on speed bumps.
 

·
Registered
2015 Grand Cherokee
Joined
·
5 Posts
The closer you get to zero (and into positive) from the negative side the more the wheel will poke out.

Stock rims are -54 or so, so when off roading the tire will tuck into the well. A -34 will push the rim out of the well somewhat and is probably as low as you want to go w/o much rub on the fender. A 0 or into positive will poke out of the well farther and you might start rubbing even on speed bumps.
Other way around - WK2 stock wheels are +56 offset
 

·
Registered
2015 Grand Cherokee
Joined
·
5 Posts
Positive offset moves the hub out from the centerline of the wheel, which moves the tire in.

Negative offset moves the hub in from the centerline of the wheel, which moves the tire out.
 

·
Registered
Grand Cherokee
Joined
·
4,388 Posts

I read somewhere most of the WK2 Rims are 8" wide with a positive 57mm offset. Pretty close to what most folks are saying so far.

25.4mm/1in

So a 10" rim with a -24mm offset, means that mounting face of the wheel will be moved roughly 1" inward from centerline of the rim (see above). So you end up with 4" of the wheel width on the inside of the rotor hub you bolt it up to and 6" of the wheel width on the outside of the rotor hub you bolt it up to.

Compare that to the stock 8" rim with +57mm offset, means that mounting face of the wheel will be moved roughly 2" outward from centerline of the rim (see above). So you end up with 6" of wheel width on the inside of the rotor hub you bolt it up to and 2" of the wheel width on the outside of the rotor hub you bolt it up to.

6"-2"

So these aftermarket rims, the outside edge of the rim/tire will extend roughly 4" from where the stock rim/tire. Ummm, looking at my WK2 that would mean these new rim and tire will be sticking out of the fenders a very significant amount. In many states it might be illegal. With the bigger diameter and larger rotating radius for outside corners, they likely rub the wheel well, probably the trim pieces around the outside of the wheel well.

Then there is suspension geometry and the wheel offset has a huge effect on it. The suspension tilts the wheels as it goes up and down and rotates, and the forces on the wheel feedback into the suspension and steering. All those angles, that the suspension is designed to create for good handling and/or keep the stress and force down to a tolerable level for the parts not to break or wear out prematurely, well all those angles change when you change the offset of the wheel, cause you're basically changing the geometry of everything and creating all new angles.

Doesn't mean you have to have the exact same offset as OEM, or the car will spin out and the wheel will break right off. Seen lots of guys that make big changes in wheel offset and resulted in wearing out wheel bearing every 10k miles, uneven wear on tires, poor braking and handling, etc.... So you have to keep it within a reasonable range. And the wheels you're looking at will produce a 3" difference in offset, that likes 40% difference compared to rim width, roughly the angles force will be exerted. That's outside the reasonable range.

General guidance I've seen, keep the difference in offset down to an inch and you should be fine. 2" is probably tops and you'll probably notice a few downsides. You get out in 3" territory, especially with wider rims, not only do have wheels sticking out a ridiculous amount, you end up with lots of other problems, like wearing out suspension parts and bad handling and braking, tire rubbing, etc....
 
1 - 6 of 6 Posts
Top