(Comparing to 4.6iS style 87 wheel offsets)

With +20 offset and 8.5" wide in front, the wheel will stick out towards the fender 12mm more than stock. Just barely out of the fenders with no front flares. 255/40/20

With +20 offset and 10" wide in rear, the wheel will stick out towards the fender 4mm more than stock. If you have rear flares, You might want a 25mm spacer instead of the usual 30mm spacer. 295/35/20

hope that helps.

(Also, if you're looking for style 87's, I have a couple MINT ones for sale.) /shameless plug

__________________
Previously owned: '03 4.6iS Dinan Supercharged