A piece of rusty metal shrapnel, just out of view, slices into your vehicle’s right front tire and carves a two-inch section out of the sidewall. You react properly, easing off the throttle and coasting gently to the side of the two-lane road. It is dark, raining, and you are alone.
Had this been 1975, you would have walked to the trunk of the vehicle and started the laborious process of swapping the wheel and tire for its identical spare, tucked safely away, before continuing your journey. But this is 2015, and the only thing in your trunk is a small aerosol tire inflator, filled with temporary sealant, designed to fix a small puncture – not a jagged gash. Frustrated and disheartened, you quickly realize that you aren’t going anywhere.
Spare tires, whether full-size or compact (same diameter as the original tire but narrower and with lower load and speed capabilities), have been disappearing from cars at an rapid rate as automakers have exploited their absence in return for increased trunk capacity, reduced weight and improved fuel economy. Today’s car shoppers are very likely to find that their new vehicle arrives with tire inflators or run-flat tires.