Well i have a 2 gal portable one that i use around the house haha. And thats good enough to take off my rims, you take about 2 bolts out then it charges and away you go again. I could probably take off anything i wanted, i'd just have to take brakes between bolts. But i only have that because it was a gift ha. At our shop we got about a 180 gal one so i dont need a big one at the house. But if i was to buy one for the house, i'd probably go with nothing smaller then a 15 gal. I'd probably go buy a Craftsman 33 gal. Then just set it in the corner of the garage and get a few hoses. Don't buy a portable one.