looking for the specs of the oem wheels so i can plug them into this calculator. trying to see if the new rims are going to stick way out or not.

ive done a bunch of searches, are the 20's 5 inches of backspacing and 19mm offset? nothing has been for sure..

 

im going to the rims with these specs:

17x9
4.5" backspacing
-12 offset

if stock is 20x9
5" bs
19mm offset

how does that calculate out? i just have this offset calculator. saying the new rims will stick out 1.22" further (31mm).