The old standby your car may not have today

Last Updated Oct 18, 2017 11:50 AM EDT

You're driving along when you hear the thump, thump of a flat tire. You go back to get the spare tire only to discover your car didn't come with one. 

That's not a mistake. In a quest to cut weight and boost gas mileage, about one-third of new cars come without a spare tire, according to AAA. And this has been true since the late 1990s.

Lack of a spare can turn an annoying loss of a few hours into schedule-busting loss of a whole day. Instead of a quick tire change by the crew from roadside assistance (or an even quicker switch if you know how to change it yourself), your car likely will have to be towed to a repair shop that can fix your flat tire or sell you a spare.

To make up for the missing spare, automakers often provide a so-called tire-inflator kit that supposedly can fix small tire punctures. However, an AAA study showed that the kits often don't work well and are no solution at all for some kinds of tire problems.

When you need a spare tire is no time to discover you don't have one. So be sure to check to see if your car has one. Even if not, does it have space to store a spare? Most cars will still have that space, except for electrics and hybrids, which fill it with batteries instead. Then take these actions:

  • Buy a spare tire. Shop prices between independent tire sellers and the tire sections of stores like Walmart. Expect to spend around $200 for a tire plus the tools you need -- a jack and lug wrench, according to Dave Bennett, AAA manager of automotive programs.
  • Keep the spare inflated. When you check your tire pressure, don't neglect the spare. Having that spare won't do you any good if it's deflated.  
  • Check on roadside assistance. Many new-car warranties now include this service. If your car is less than three years old, it should be in effect. If not, consider joining your local chapter of AAA. Dues are typically $50 to $100 a year, depending on your location and what level of membership you select.

Roadside assistance, of course, will help you with problems other than a flat tire. But AAA officials say tire problems are among the top reasons members call for roadside help. 

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    Jerry Edgerton, author of Car Shopping Made Easy, has been covering the car beat since Detroit companies dominated the U.S. market. The former car columnist for Money magazine and Washington correspondent for Business Week, Edgerton specializes in finding the best deals on wheels and offering advice on making your car last.