I searched through a lot of threads but came up empty handed

Is backspace the only factor that matters when it comes to the wheel sticking out? Or is offset important too.

I'm looking at several 16x8 wheels.

One wheel has 0 offset and 4.5" backspacing

One has -6mm(1/4" roughly) and 4.25 backspacing

One has -11mm((almost 1/2") and 4" backspacing

So, are all these going to stick out the same or more as you go down the list?

It is my understanding that the stock aluminum wheels have 6.25 backspace, but I'm unsure of the offset.

Going off my fender flares, it looks like I could have the tire move out about 2" and be inline with flare.

If that is what I'm trying to do, would the 4.25" backspace just mean the tire is going to stick out two inches more? Or does the offset come in and make a difference?

All I would like to do is keep the wheel within reason(no more then a 1/2" outside the fender flare). I had an 04 GMC with the 16x8s and 4" backspace and -11mm offsel and 265s and they were perfect with fenderflares(in front, that sticks out more, stupid Chevys).

Also, would a 16x9 with 0 offset and 4" backspacing stick out even more, less or the same?

 

In your examples you'll see that as the offset grows(negative) backspace shrinks by the same amount.
(why one is measured in inches and the other in millimeters is beyond me.

16x8 with 6.25" backspace (stock basically) will look just like the stock wheels, sticking-out-wise.

16x8 with 4.5" backspace will stick out almost 2 inches. (6.25- 4.5 = 1.75).

The bigger the backspace, the less it will stick out.

You'd be hard pressed to find an aftermarket wheel with stock backspace though, 99% of them are 4-4.5 inches.

If you're comparing it to a 16x8 with the same offset/backspacing, it will stick out 1/2 inch more, as the wheel is 1 inch wider, 1/2 inch on either side of the mating surface.


phox

 

Ok, so wheels with 4.5" backspacing stick out 1.75" and 4.25" will stick out two inches, no matter the offset?

 

Pretty much, yes.

Offset and Backspace will go hand in hand,
the only factor that might make one change and not the other is the thickness of the mating surface.
I.E. An aluminum rim will have a thicker mating surface than a steel wheel.
An aluminum 8 inch wheel compared to a steel 8 inch wheel with the same backspace, the aluminum one will have a different offset, and theoretically, will stick out slightly more than the steel one.

This is just the rim, the width of the tire will also dictate how much sticks out.
10 inch wide tire will obviously stick out less than a 12 inch wide tire, both mounted on the same rim.

My 315/75R16 tires mounted on 16x10 rims with 4.5" backspace stick out exactly 2 inches past the fender line.
2 inch wide Bushwacker Extend-a-Fender's cover them perfectly.


phox