Someone local is selling a set of Perelli P Zero Nero 215/45R18XL
Will these fit stock rims? I'm so lost
I know that 18 is the rim size.
What are the other numbers?

Stock is 225/45-18. These will be narrower and a bit shorter than the stock fitment, probably not a good idea.

Yes it will fit. but not the correct size.
The 45 is the sidewall height. 45% of the width.
The 215 is the tread width.

I wouldn't get them. A little to narrow.

they will fit, but i wouldn't do it

if they're cheep, do it.