I don't really think that anyone will know that answer, but if your stock spare is easy to get to and the same size wheel it's easy to figure out
Flip the wheel on the ground (outside down) and place a straight edge across the rim (but not on to the tire) A scrap 2x2 board is perfect since you might have to cut it to fit.
Then just measure down to the stud holes, and you've got the offset.
If you try surfing some wheel companies web sites you might find a fitment guide somewhere as well