width and offset question
 

What is the widest width and offset that I can go on the back of scion xb2 without rolling fenders.

What drop are we talking dude? With a decent drop, you might be around 9" and +25

offset width
 

I have tanabe df springs

You will never have to roll your fenders ever with that drop. You need to be tucking to have to worry about stuff like that. I figured you were talking about with coilovers or something. Your fenders will never hit your tires because the drop is still so high. So you will never need to roll fenders.

Just been thinking of changing wheels again and looking to go more agressive then always playiing it safe.

The term "aggressive" needs to have a big drop associated with it, otherwise the wheels are just "wheels". Not to mention, "aggressive-capable" wheels look terrible on a car with wheel gap. You can put whatever wheels you want with whatever width, as long as the offset keeps the insides of the wheel from rubbing.

Your right about wheel gap. Looks so much better tucking tire or rim. I found a good deal on air suspension. So trying to get the right wheels and offset. I have had my df springs since 2008. Getting bored with the drop. Bored with my wheels also.

Sweet. Get it.

Fitment is all relative to tire size and stretch, wheel offset/width/diameter.
All of these items are relative to each other and being 'aggressive' or 'flush'.

Since you're on DFs, I would keep in the 8.5-9 range with an offset not exceeding +40mm and a tire size not exceeding a 225 width. You can run a 235/35R19 on a 19x9.5 +45 without rolling, but that's about as aggressive as I'd feel comfortable without rolling.

Never say never rub
with enough weight in the xb you can rub with a df210 drop

i agree with vegans advice