hi all,,new to site,,can someone please help me,,i want to get new wheels for my 2010 stx,,i am running 325/65/18 tires,,so i need a 9" wheel,,but i dont want them to stick out far so does that mean i should get a 0 offset,not sure what offset means,,thanks

 

Offset is the difference either positive or negative in the delta from the wheel centerline and its backspacing. Backspacing is derived from measuring from the inboard flange (the lip on the backside of the wheel) to the hub mounting pad (the part that actually makes contact with your hub when you put the wheel on). With that said how far a wheel sticks out or is tucked is a combination of the offset and the wheel & tire width. In your case a 0 offset should cause the tire to stick out. I believe you are going to need to go with a more positive offset. What wheels are you looking to run, is your truck lifted in any way?

 

I have"nt really settled on any specific wheel yet,,kinda like pro-comp 1079,, those have a 6mm offset with a 4.75 backspacing,,not sure how they will work,,I don"t have a lift kit,, I do have an autospring 2 1/2" level with a 3" rear block,,also running with 1/4" spacers because my 325/65/18 rub a bit at full lock,,

 

That wheel will stick out 2.25 inches farther than your OEM wheels. You will need more lift to fit those with a 325/65-18 (35x13.00) tire.

 

wow,,thats more than i was looking for,really cant afford a lift right now,,so i guess i should be looking at 0 offset with 5.00 backspace,does that sound right?

 

actually i was wrong,,that wheel i am looking at has a -6mm offset,,not a +6mm,,so does that bring me in more or out more,,really appreciate the help,,to recap wheel is 18" with -6mm offset,,4.75 backspace on a 325/65/18 am i gonna stick out alot,,thanks

 

I was going by the backspacing you gave. I didn't even consider the offset you listed as BS is so much easier to understand.

 

ha ha,,I know wandell,,offset really screws me up too,, hey MD,,what exactly do you mean by the delta? does a negative off-set mean the wheel will stick out more than with a positive off-set,,in other words,,A negative off-set puts the wheel out more and a positive off-set puts the wheel in more,,with a zero off-set being center?????????? backspacing i pretty much understand,,off-set is a different story,,thank you both for the help!!!!!

 

Sorry, Delta - math term for change in or difference. So if you have a 10" wheel with 4.5" of BS your centerline is 5" and your offset is -.5" or -12.7mm (this is done by subtracting your centerline from your BS (4.5 - 5 = -.5) convert to mm = -.5 x 25.4 = -12.7)
So the rule is:
If backspace is less than the wheel centerline the offset is negative
If backspace is greater than the wheel centerline the offset is positive
Yes and No, zero offset puts the centerline and the backspacing at the same location, in other words a 10" wheel with 5" of backspacing has 0 offset, however this is not relative to your wheel well, in other words it does not mean its centered and does not stick out, Its more so relative to your hub, your going to have 5" of wheel out past your hub, plus the width of the tire. Basically what I am saying here is a 0 offset wheel can still stick out past your fenders (the wider the wheel the more it sticks out). You are correct about the positive offset puts wheel in more and vise versa but keep in mind the wheel width matters in the end all result.

So for a final example calculation the OEM 18" wheels are 7.5" wide with 5.5" BS this give you a centerline of 3.75 so (5.5 - 3.75 = 1.75" or +44.45mm of offset).

I hope this is not confusing, hit me up if its not clear.

 

actually that was a great explanation,,thank you very much for taking the time,,now i have a pretty good sense of wheel off-set,,thank you MD!!!!!!!!!!!!

 

Your welcome