Recently purchased a 2018 Outback 3.6 Touring and would like to keep it as stock as possible but mod it a notch up. New to Subaru's and love this thing more than my MB S550 I just got rid of. I'd like a wider stance and more aggressive tread without having to buy new rims to get those features. I've used spacers on other sports sedans but never on an SUV and since going off-road over light terrain is about the maximum of adventure I'll be using this great vehicle for plus daily driving to work....does anyone suggest a decent hardware set-up? I'm thinking of putting 20mm spacers to really kick the tires out.

Are your wheel-studs long enough?

Good point. 

seems like a lot, I bet there would be some rubbing in the front but, I have noexperience with that.

 

and you'd probably want aftermarket mud/rock guards....

20mm would most likely be bolt on, as in they have their own studs, so they bolt onto your hub, and then the wheel bolts onto them. I've used them a lot, and had zero issues. Most people use 25mm, to make sure the length of the wheel studs clear the back of the wheel. Your wheels will sit close to flush, but won't poke, and with stock size tires, shouldn't rub at all.

They do put more strain on your wheel bearings.