How to Tell If Your Spare Tire Is Still Safe to Use

Your spare tire is meant to protect you during an emergency — but only if it’s safe to drive on. Many drivers don’t realize their spare has been aging, drying out, or weakening for years while sitting unused. By the time you need it, it may already be unsafe.

Here’s how to quickly check whether your spare tire is still safe to use, and what to look for before depending on it.

Look for Cracks in the Sidewall

The first and most obvious sign of an unsafe spare is sidewall cracking.

Check for:

• Fine surface cracks

• Web-like patterns

• Deep, visible splits

• Cracks near lettering or bead

These cracks indicate dry rot, which makes the spare dangerous to inflate or drive on.

Check the Rubber Color and Texture

Healthy rubber is:

• Dark black

• Slightly flexible

• Smooth

Unsafe, aging spare tires often look:

• Light gray or faded

• Chalky

• Dry or dusty

• Rough or brittle

Press your thumb into the sidewall. If it feels hard and stiff, the rubber has lost its oils and is no longer safe.

Inspect for Dry Rot Around the Tread and Bead

Dry rot doesn’t only appear on the outer sidewall.

Check:

• Tread grooves

• Inner sidewall

• Around the bead (where tire meets rim)

If cracks are present anywhere, the spare is compromised.

Check the Tire’s Age (Date Code)

All tires include a DOT date code, such as:

DOT 2317→ 23rd week of 2017

General safety rules:

• Under 6 years → Usually safe

• 6–10 years → Inspect carefully

• 10+ years → Replace immediately

Even if unused, spare tires age and become unsafe.

Make Sure the Tire Holds Air Properly

Inflate the spare to the recommended PSI and let it sit for several hours.

If it loses air, it may have:

• Bead cracks

• Structural weakness

• Internal dry rot

• Damaged valve stem

A spare that cannot hold air is not safe to use.

Look for Bulges, Bubbles, or Uneven Spots

Run your hand across the tire.

Unsafe signs include:

• Soft bubbles

• Raised areas

• Bulging sidewalls

• Uneven patches

These indicate structural damage or separation inside the tire.

Check the Spare Tire Cover (Or Lack of One)

If your spare has been:

• Uncovered

• Exposed to sun

• Rained on for years

• Stored outside in heat or cold

…it is far more likely to be unsafe.

Sunlight alone causes most spare tires to dry-rot long before they’re ever used.

A quality SpareCover® greatly reduces these problems by blocking UV rays and weather.

Make Sure the Tread Isn’t Severely Aged or Cracked

Even unused tread can break down.

Look for:

• Cracks inside the grooves

• Loose rubber flakes

• Missing chunks

• Faded tread blocks

This indicates the spare can’t flex safely while driving.

Confirm the Spare Matches the Vehicle’s Tire Size Requirements

If a previous owner replaced the spare incorrectly, you may have:

• An incompatible tire

• A mismatched load rating

• The wrong diameter

• An undersized emergency spare

Driving on a mismatched spare can damage your drivetrain.

Check the Wheel and Hardware

A spare may be unsafe if the wheel itself is compromised.

Look for:

• Rust

• Bent rims

• Damaged studs

• Loose bolts

• Corrosion on inner wheel edge

A good tire on a bad wheel is still unsafe.

When Should You Replace Your Spare?

Replace the spare immediately if:

• It’s over 10 years old

• It has visible cracking

• The rubber is hard or brittle

• It doesn’t hold air

• The tread is separating

• It has bubbles or deformities

• It has been uncovered for years

• You wouldn’t trust it on the highway

Your spare must be 100% reliable — not “probably fine.”

Final Thoughts: Don’t Wait Until You Need It

Your spare tire is a lifeline during emergencies. A quick inspection can tell you if it’s safe to use or needs to be replaced. Protecting your spare with a high-quality SpareCover® keeps it healthier for much longer by blocking UV rays, heat, and weather exposure.

A protected spare is a reliable spare — and it may be the one thing that gets you safely back on the road.