^^^ Uh, I don't think it works that way...

I've taken a few 2,000-mile trips without a spare...but my general rules are:
Not getting hit by the side of a road
Old-car bumper jacks & tire irons suck
Short distance on mis-matched OD is survivable
Rims on a couple of my vehicles can be sacrificed if necessary
Credit card & tow is the final back-up plan if I've painted myself into a corner