I carry a mounted spare. Changed a blow-out on the side of the road just 3 or 4 weeks ago out in the middle of nowhere in west Texas. Of course it was the inside dually. Roadside assistance would have taken 3 or 4 hours just to get to me. I called tire stores at the closest town (about 60 miles) to replace the blown tire and they didn't have my size but could get it in a couple of days. I was up and running in an hour or two. Only tools needed was a jack, lug wrench and a cheater pipe. I drove another hundred miles or so and got a new tire the next day.