The tool to mount a tire onto a wheel costs between $50 and $2500 dollars and is very large. The alternative - a spare wheel - is a kludge! Cars carry around an

The tool to mount a tire onto a wheel costs between $50 and $2500 dollars and is very large. The alternative - a spare wheel - is a kludge! Cars carry around an entire tire and wheel all the time in a special compartment because you can't expect people to mount tires themselves. Or modern cars spec run flat tires which come with a host of their own tradeoffs.