Should I Replace a Spare Tire?

Everyone · Explainer · Updated October 1, 2026 · LearnLife Editorial

What Exactly Is a Spare Tire and Why Do Cars Carry Them?

A spare tire is an extra tire stored in or on a vehicle to temporarily replace a flat or damaged tire. Most cars come with a spare tire kept in the trunk, under the rear cargo area, or mounted underneath the vehicle. There are two main types of spare tires: full-size spares that match your regular tires and smaller compact “donut” spares designed for short-term use. The key role of a spare tire is to get you moving safely after a flat or blowout, allowing you to drive to a tire repair facility or home without waiting for roadside assistance or towing.

Knowing the exact location of your spare tire is important. It could be under the floor panel in your trunk or secured on the underside of the vehicle. Check your owner’s manual for details and practice accessing it so you can retrieve it quickly in an emergency.

How Does Using a Spare Tire Work? A Step-by-Step Example

Suppose you are driving home when you hear a thumping noise and feel your car pulling to one side. You pull over safely and discover a flat tire. Here’s how to replace it with your spare:

1. Find a safe location: Turn on your hazard lights, pull over to a flat, stable spot away from traffic, and apply the parking brake.
2. Get your tools and spare tire: Open your trunk or storage area and remove the spare tire, jack, and lug wrench.
3. Loosen the lug nuts: Use the lug wrench to loosen (but not remove) the lug nuts on the flat tire by turning them counterclockwise.
4. Lift the vehicle: Place the jack under the vehicle’s designated lift point, usually found near the flat tire, and pump or crank it to raise the tire off the ground.
5. Remove lug nuts and flat tire: Now fully unscrew the lug nuts and carefully remove the flat tire.
6. Mount the spare tire: Align the spare tire with the wheel studs and slide it onto the hub. Hand-tighten the lug nuts.
7. Lower the vehicle: Slowly lower the jack until the spare tire touches the ground, then remove the jack.
8. Tighten lug nuts: Use the lug wrench to tighten lug nuts firmly in a star or crisscross pattern to ensure even pressure.
9. Check the spare’s air pressure: If you have a pressure gauge, verify the spare tire’s inflation or inflate it if needed.
10. Drive cautiously: Remember that compact spare tires usually have speed and distance limits, often no more than 50 mph and about 70 miles, so drive carefully to a tire repair shop.

This step-by-step approach prepares you to handle a flat tire safely and effectively.

Why Does It Matter to Replace a Spare Tire When Needed?

Spare tires can deteriorate with age and environmental exposure even if unused. Rubber compounds dry out, crack, and lose flexibility due to heat, sunlight, and time. A damaged or old spare tire risks blowouts or poor handling when you rely on it, potentially leaving you stranded or causing an accident.

For example, if your spare tire has visible cracks on the sidewall or has lost air pressure repeatedly, it may fail during use. Replacing an unusable spare ensures you won’t be stuck waiting for a tow on the side of the road. This is especially important if you drive frequently, travel long distances, or live in remote areas where help may be far away.

A reliable spare tire protects you from unexpected delays, expensive towing fees, and possible damage to your vehicle’s suspension or brakes caused by driving on damaged tires.

What Terms Are Often Confused with Spare Tires and How Are They Different?

Some terms related to tire emergencies are often mixed up with spare tires:

• Run-flat tires: These tires can temporarily support the vehicle after a puncture, allowing limited driving at reduced speeds without changing the tire immediately.
• Tire sealants or fix-a-flat products: Liquids or sprays you inject into a tire to temporarily seal small punctures from the inside, giving you time to reach a repair shop.
• Tire patches and plugs: Professional repairs applied to fix punctures without removing the tire.
• Spare tire: A physical, separate tire stored on the vehicle to replace a flat or damaged tire.

Unlike sealants or patches which repair a tire, or run-flat tires which allow limited driving without replacement, a spare tire is a fully functional backup tire you install to continue driving safely.

Understanding these distinctions helps you choose the right option during a tire emergency.

How Can You Tell When Your Spare Tire Needs to Be Replaced?

Follow these steps to check if your spare tire should be replaced:

1. Find the manufacture date: On the tire sidewall, locate the DOT code. The last four digits indicate the week and year of manufacture—for example, “2517” means the 25th week of a certain year.
2. Assess tire age: Tires generally should be replaced every 6 to 10 years regardless of use because rubber deteriorates over time.
3. Inspect for visible damage: Look for cracks, dry rot (small cracks on the sidewall), bulges, or worn tread. These are signs the tire’s integrity is compromised.
4. Measure air pressure: Use a tire pressure gauge monthly to check if the spare holds recommended air pressure. A drop means it might have leaks or damage.
5. Consider storage conditions: Tires stored in hot, sunny, or chemically exposed environments tend to degrade faster.

If your spare tire is old, cracked, or does not hold air properly, replace it. For example, if you notice dry rot or multiple cracks on the sidewall, the tire’s strength is reduced and it should not be relied upon.

What Are the Practical Steps to Replace a Spare Tire?

Replacing a spare tire involves selecting the correct replacement and installing it properly:

1. Verify your vehicle’s spare tire size: Check your owner’s manual or the markings on the current spare tire.
2. Purchase a suitable replacement: Visit a tire dealer or auto parts store. A full-size spare is best if your vehicle can accommodate it, but a compact spare is acceptable for short-term use.
3. Inspect the new tire: Ensure no damage and that it matches specifications.
4. Store the new spare properly: Place it in the designated spot, secure it tightly to prevent movement.
5. Maintain air pressure: Inflate the new spare to the recommended PSI and check it regularly.
6. Keep your tire-changing tools ready: Confirm the jack, lug wrench, and other tools are in good working order and easily accessible.

By following these steps, you ensure your spare tire is ready for emergencies. Practicing tire changes at home can increase your confidence and safety.

What Should You Do After Installing and Using a Spare Tire?

After installing a spare tire, drive carefully and avoid high speeds or long distances. Compact spares generally have speed limits around 50 mph and distance limits near 70 miles—enough to get to a repair shop. Full-size spares allow more flexibility but still require timely replacement or repair of the original tire.

Once at the tire shop, have the flat tire inspected and repaired or replaced as needed. Do not use the spare tire as a permanent replacement without professional advice. After using a spare, check your tire-changing tools and restock any supplies used.

If you’re uncomfortable changing a tire yourself, call roadside assistance. Regular reviews of your emergency procedures and equipment improve safety.

When Should You Seek Professional Help Regarding Your Spare Tire?

Consult a tire professional if you:

• See visible damage or suspect issues with your spare tire.
• Are unsure about the correct spare tire size or type for your vehicle.
• Need guidance on whether your vehicle uses a traditional spare or run-flat tires.
• Have trouble accessing or storing your spare tire.
• Want to confirm proper tire pressure and maintenance routines.

Professionals can assess safety, recommend replacements, and clarify your vehicle’s tire emergency options. Including spare tire checks in regular vehicle maintenance adds peace of mind.

Frequently asked questions

How often should I check my spare tire’s air pressure?

Check your spare tire’s air pressure at least once a month. Tires lose air gradually over time, so maintaining the correct pressure ensures the spare is ready when needed.

Can I drive long distances on a donut spare tire?

Donut spares are designed for short-term use only, typically limiting speeds to about 50 mph and distances to roughly 70 miles. Driving beyond these limits risks safety and tire damage.

What’s the difference between a full-size spare and a donut spare tire?

A full-size spare matches your regular tires in size and tread and can be used temporarily like a normal tire. A donut spare is smaller and lighter but has restrictions on speed and distance.

How do I find the manufacture date on a tire?

Look for the DOT code on the tire’s sidewall. The last four digits indicate the week and year it was made—for example, “2517” means the 25th week of a particular year.

What if my car doesn’t have a spare tire at all?

Some newer vehicles use run-flat tires or tire repair kits instead of spares. Learn how to use these kits or consider buying an aftermarket spare compatible with your vehicle.