Can someone help me understand wheels?

Ok, so i knew nothing about wheel sizes and fitment and have been trying to educate myself by reading up on them. I found a VERY good thread here
https://www.tacomaworld.com/threads...lifted-info-inside-complete-with-poll.514755/

Eccracer's post in that thread is great but i am confused on this section of his post:

"Something to consider while selecting your wheels is that the wider the wheel and the further it sticks out, the more rubbing you will have.

Most popular wheel fitment options:
16" x 8" 0mm offset 4.5" back spacing
16" x 8" -12mm offset 4.0" back spacing
16" x 8" -25mm offset 3.5" back spacing

17" x 8" 0mm offset 4.5" back spacing

17" x 8.5" 0mm offset 4.75" back spacing
17" x 8.5" -6mm offset 4.5" back spacing

17" x 9" -12mm offset 4.5" back spacing
17" x 9" -38mm offset 3.5" back spacing"

If you look on which is a great site i read about in another thread, that has a great calculator. So if i enter 245 75 16, 7 (width) 25 (offset) stock wheels & tires. Then enter 265 70 17, 9 (width) -12 (offset), as my new setup it says the outer wheel will "poke out" 62.4mm (4.5" backspacing) more than my stock wheels. If you change the -12 to 12, the wheels only "poke out" 38.4mm (5.5" backspacing) more than stock wheels. I am reading in other threads and in Eccracer's post that 4.5" of backspacing is kind of the sweet spot. Why is that when they stick out 24mm more? Would they not rub more since they stick out further?

Maybe i am missing something obvious and not grasping the concept yet. Any help would be great.

 

more than 4.5bs will rub your uca (depending on tire), and less bs will rub your cab mount (again, depending on tire), which is why it is the "sweet spot". stock wheels are 4.5bs, but they are narrower (7") than most aftermarket (8-9"), so don't have as much poke. assuming you want to run a larger tire, 4.5bs is the best compromise to minimize rub. the wider the tire and wheel, the more likely you are to have issues either way.

 

I agree 4.5”bs is the sweet spot.

 

The tire is wider. So it sticks out from the center of the wheel on both sides.
2 kinds of rubbing. In can have rubbing on frame and uca.
Sticking out rubbing may be on fender/wheel well.
So you need a balance of offset. The tire isn't only wider on the outside.

 

When you turn the steering wheel left the outside trailing edge of the drivers side tire will rub the cab mount if the tire is too wide or backset to little. Turn the wheel right and the inside leading edge of that tire will rub the uca if the tire is too wide and backset too great. Opposite for passenger side.