Offsets

[bobafetske]

I'm trying to figure out how offsets work. positive and negative and all that. I want a wider stance and some tire outside the wheel wells. I have the 3" leveling kit from www.fordrangerlifts.com. I saw a thread where a guy didn't cut the crash bars or trim or remove anything and was running a 285/17 tire. He said his wheels were +12 mm offset. I'm just trying to figure out what that means so i order the right wheels. Thanks in advance.

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[RoadBoss]

to keep it as simple as possible, offset is essentially how far the wheel will be set in or out from where the wheel bolts to the hub on the vehicle. Positive number indicates that the center of the wheel sits IN from the hub mounting surface. a negative number indicates that the wheel sits OUT from the hub mounting surface.

stock ranger wheels are +55mm, so a +12mm wheel is going to be centered 43mm farther OUT than the stock wheels.

also if you are going with a wider tire, this will add to it. a 285 is 30mm wider than the stock 255 tires, so split between the inside and outside, you're adding an additional 15mm of tire on each side.

So now, on a +12 offset wheel with a 285 tire, the outside edge of your new tire is going to sit 58mm farther out than your stock wheel/tire package. (43mm from the wheel offset, and 15mm from extra tire width)

Also wheel width can make a difference, but assuming your tires are going to be bulging over the edge of the wheel, you won't be noticing that too much.

 

[RoadBoss]

Also, I'm pretty confident with a +12 wheel and a 285 tire, you're going to be rubbing on the front crash bar at least. It will depend on the height of your tire as well of course... I'm assuming you're talking about a 285/70 17, which is about 33" diameter.

I believe the only guys running 33's without rubbing or removing anything are the ones on stock offset wheels and narrower tires (255/80r17)

 

[AzScorpion]

Here's another recent post that has some good info and a chart that might help explain things too.


https://www.ranger5g.com/forum/threads/can-yall-help-me-figure-out-the-math.9106/#post-167671

 

[bobafetske]

Also, I'm pretty confident with a +12 wheel and a 285 tire, you're going to be rubbing on the front crash bar at least. It will depend on the height of your tire as well of course... I'm assuming you're talking about a 285/70 17, which is about 33" diameter.

I believe the only guys running 33's without rubbing or removing anything are the ones on stock offset wheels and narrower tires (255/80r17)

Gotcha, that was a good break down

 

[Msfitoy]

Is there such thing as +12? I've often heard of -12...mine is +20...

 

[RoadBoss]

Is there such thing as +12? I've often heard of -12...mine is +20...

yes, +12 and -12 are both fairly common.

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