All drivers are at risk of getting a flat tire, but many new-car buyers might be surprised to find their new vehicle doesn't come with a spare.

About 28 percent of 2017 model-year vehicles did not come with a spare tire, based on a new study by AAA. That figure is actually down from 36 percent in 2015, in part due to increased sales of SUVs, which do have spares.

AAA reports that it aided more than 450,000 members last year who were without a spare tire.

“Having a flat tire can be a nuisance for drivers, but not having a spare could put them in an even more aggravating situation,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair, in a statement. “This can turn the relatively routine process of changing a tire at the roadside into an inconvenient and costly situation that requires a tow to a repair facility.”

Spare tires have been vanishing from standard equipment lists in recent years as automakers seek to boost fleet fuel economy averages. Removing the spare tire can drop 30 pounds from the vehicle's weight. And when it comes to mpg, every pound counts. 

Today's vehicles often have run-flat tires or an emergency flat-tire inflation kit with an aerosol sealant and a compact air compressor in place of the spare tire.

CR Tire Program Manager Gene Petersen advises, “Car owners should prepare for the eventuality that they will experience a flat tire, starting with making sure the car includes a spare or at least tire inflation kits, or know that you have some limited mobility if the car has run-flat tires and that the drivers are familiar with their operation.”

Run-flat tires allow a motorist with a deflated tire to continue driving for some distance, maybe all the way home or to a service center for a replacement.

And emergency flat-tire inflation kits are just a temporary fix and can tackle only small tread punctures. Larger holes or a compromised sidewall are too much for the sticky fluid to secure. In those cases, motorists will need to call for roadside assistance. (Learn more about roadside assistance options.) Plus, as AAA points out, using an inflator kit could damage the tire's pressure-monitoring sensor.

Got a flat? Read: How to Change a Car Tire

If You're Buying a Car

When you're buying a new car, find out whether it comes with a spare tire, an inflation kit or has run-flat tires. In many cases, even though a spare tire might not come with a car, it could be readily available through the dealership.

When weighing the decision of what you would prefer, remember there is the inconvenience and expense of having to buy sealant refill kits from the dealership after using the tire sealant system that came with the car to make a tire repair. Official kits can cost over $80 and they are just a temporary fix—one that may not work.

There are numerous choices in aftermarket sealant systems including simple pressurized can products and kits with sealant and a compressor. Look for products that claim to be safe for the tire pressure monitoring system (TPMS) and/or are water soluble, as they will be easier for the repair shop to clean up, potentially reducing the cost for the inevitable professional repair. Also, check the directions for storage, as some cannot withstand the high temperatures inside a car in summer. (Read “Convenient Tire Sealants to Fix a Flat Tire.”)

spare tire and jack

Car Owner To-Do List

All tires lose pressure over time, which is why we recommend including your spare as part of a monthly tire pressure check. If it's been awhile since you inspected the spare tire, chances are it is low or even flat. (See our tire pressure gauge buying guide and ratings.)

  • If you drive an SUV, minivan, or pickup with the spare stored under the vehicle, check to make sure any nuts, bolts, brackets, or chains holding it can be loosened, and that you can get the spare out. Penetrating oil can help with stubborn fasteners. Even if the spare is in the trunk, the related hardware used to secure it can be subject to corrosion. Check all fasteners, and pull the tire out to clean any debris or dampness underneath it.
  • Don't forget to check your jack to make sure it is functioning properly, and make sure you have all the pieces and parts you need to use it, along with a lug wrench.
  • If you've never changed a tire on your present vehicle, consider a dry run in your driveway or other safe place to ensure you're comfortable doing it and have all the necessary components. Consult your vehicle owner's manual for tire care and instructions for safely changing a tire.
  • If you have an older vehicle, you should replace tires—even an unused spare tire—after 10 years or sooner, depending on what the vehicle owner’s manual recommends. To check how old a tire is, look for the tire identification code one or both sidewalls of the tire. It will start with DOT and end with four numbers; the first two are the week and the last two are the year of manufactures. So a 2317 code, for example, would mean the 23rd week of 2017.
  • If you have a tire inflator kit, check its expiration date. Kits typically need replacement every four to eight years.