Spare a Moment to Learn About Spare Tires

Do you know what type of spare tire your vehicle has?

The Spare Tire - A Friend When You're in Need

Did you know that AAA has seen a 26% increase in flat tire calls that have resulted in a tow in the last 12 months because the vehicle did not have a spare tire?

This increase is not arbitrary. As automakers are looking for ways to cut production costs and reduce overall vehicle weight to meet the U.S. government mileage per gallon standards, they are eliminating the spare tire and the corresponding tire change tools as standard equipment on new vehicles. When buying a new car, consumers should be aware that the spare tire may not always be included, and take the necessary steps to ensure their car has one.

It is important to understand what equipment is included with your vehicle prior to getting a flat tire. Below is a break-down of the various equipment options you may find in your vehicle.

Full Size Spare Tires

Full size spare tires are typically found in trucks and large SUVs and are the best spare tire option available. With full-sized matching spares, the air pressure in the spare tire should be checked regularly and it should be included in the rotation when getting your tires rotated. This helps to ensure the same wear as the other four, making it more likely that this tire can become a permanent replacement.

  • Benefits: Matches the other four tires, no speed restrictions
  • Limitations: Hard to find as standard equipment on new vehicles

Temporary Spare Tires

In some cases, vehicles are equipped with full-sized temporary spares. These match the original tires in dimensions but have a more light-weight construction with shallower tread depth, another weight-saving measure for fuel economy improvement. The upside to these spare tires is that they are the same size as the original tires. However, they are only meant to be used temporarily until you can get a proper replacement.

  • Benefits: Same size as the original tires, lighter than regular tires, no speed restrictions
  • Limitations: Hard to find as standard equipment on new vehicles, temporary solution

Space Saver Spare Tires

A space-saver, or donut, is a spare tire that is shorter and narrower than the vehicle’s standard tires. They operate at much higher pressure, 60 psi, in order to match the load capacity of a larger tire. The advantage with space savers is that you have a spare tire that does not take up much room in your trunk. The disadvantage is, once again, that it is a temporary solution and you will still need to purchase a replacement tire. Additionally, you should not exceed 50 mph while running on this spare and they should not be driven for more than 70 miles.

  • Benefits: Light, space saving spare tire
  • Limitations: Temporary solution, speed restrictions not to exceed 50 mph, mileage restrictions up to 70 miles

Tire Sealant Repair Kit

Your vehicle may be equipped with a repair kit rather than a spare tire. The kit likely includes both a sealant and a DC-powered air compressor, meant to replace any air the tire lost before you repaired the puncture. It is important to note that this solution can only be used in the situation of a small puncture, such as one acquired from running over a nail. This is not a solution if there is a gouge on the sidewall of the tire, or if the tread has come apart. AAA does not recommend a tire sealant as a permanent solution. You should have your tire inspected by a professional technician to ensure that the tire is still safe to have on your vehicle.

  • Benefits: Takes up little space in vehicle
  • Limitations: No spare, temporary solution, can’t use on sidewall blowouts, rim needs to be cleaned and removed

Run-Flat Tires

Run-flat tires, or run-flats, eliminate the need for a spare tire due to their ability to continue to run while flat, and have risen in popularity over the last several years. They first arrived on the scene in sports cars with limited space, such as a Lotus Elise. Soon they were found on performance sports cars and luxury vehicles to reduce weight by eliminating the spare.  The reason this tire is able to continue to run even while flat is due to heavily reinforced sidewalls. Rather than relying on the support of the air pressure in the tire, the vehicle relies on the stiffness of the sidewall to maintain a round surface that will continue to roll.

While run-flats may sound like the perfect solution to a flat tire, there are still limitations to consider. While you can continue to drive on a flat tire, you must reduce your speed to 50 miles per hour or less, and the tire will still require replacement. The cost to replace a run-flat can be much higher than the standard tire equivalent, and run-flats typically need to be replaced in pairs. Another downside is that run-flats will need replacement roughly 6,000 miles sooner than traditional tires, meaning you could spend more money over the lifetime of the vehicle.

  • Benefits: Eliminates the need for spare tires
  • Limitations: Costly, speed restrictions not to exceed 50 mph on flat tire, replace tires more frequently

How can you be proactive?

The first thing to do is determine what type of flat tire solution is equipped with your car.  If you are shopping for a new car, ask if the vehicle has a spare tire. If purchasing a new vehicle, you may have the option to add a spare tire or repair kit even if it is not standard equipment. If your current vehicle is missing a spare tire and does not have a repair kit, you can purchase a repair kit at an automotive parts store. Make sure that every person in your household who might drive the vehicle is informed as to what type of spare tire or repair kit the vehicle contains—It’s better to be acquainted with your spare tire and its complexities before you are sitting on the side of the road with a flat tire.

And even with the different options, it is important to know their limitations.  If your vehicle is equipped with run-flats or has a donut be sure you know the limitations with each.  You are not going to be able to drive 70 miles an hour for the next month until you have time to go and purchase a replacement tire.  These alternatives are temporary fixes, not permanent solutions.

To reduce the chances of a flat tire, AAA recommends that you check your tire pressure frequently. Properly inflated tires are less likely to fail and are more resistant to punctures. As always, AAA will be here to assist you if you get a flat tire. You can call us at 1-800-222-4357, request service online at or use the AAA Mobile app to request flat tire service as part of your membership.