Offset.

I have 5100s at the highest setting with 888 x coils, SPC uca's.
275/70/17 BFG Ko2s
My rims have a backspace of 4.75
Offset of 0.

I have ordered a different cheapo rim for a spare spare. I also got 5th tire the same as the other 4.

The spare rim has the same backspacing 4.75
But the offset is -6

Will i have any issues? ??

 

Most likely no. It's only a 1/4" farther poke out than your 0 offset. If your closer than an 1/4'" clearance (lock to lock) it would be.

 

The spare will likely rub on full lock mounted up front. I wouldn't worry about it.
just be aware its going to be close IF you ever get a flat tire.

Always the option of swapping front to rear too if front tire gets a flat, then good to go.

 

This is what i was wondering.
So it should put the rim about 1/4" farther inset?

 

1/4" out

 

No, the spare would stick out more. A good read on offset:

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=101

By the way, your spare is wider than the other wheels? Seems backwards.