Offset Question

[Harry101]

Hello all,
I'm a newbie to the forum and also to BMW ownership.
I have a 2022 X3 x Drive 30i and I was looking to buy a set of used 18" winter tires. I know I'm early but ss my Grampa once told me, the early bird gets the worm... but the 2nd mouse gets the cheese :-)
So, to my question. I'm looking to buy rims and tires, I know the bolt pattern is 5x112 but when I've looked at different sites the specs for the offset vary from+20 to +45. What is the allowable offset I can use without using spacers?

thanks,
Jeff

[Yurokae]

I would assume you should match the offset of your OEM rims - so you are assured of no fitment problems at all, right? - unless you have a very specific reason to change it?
You can almost always find the offset of your existing wheels by looking at the back side of the wheel spokes - usually cast in - like (ISxx) with xx in mm offset.

The other wheel specifications that pretty much covers it:
PCD Bolt Circle diameter.
Center Bore diameter in mm.
basic wheel size width x diameter - for example 8J x 18