If you own a vehicle that has a spare tire, it’s vital you know how long you can safely store it, and how long you can run on it before it becomes unsafe.
So, how long do spare tires last?
The amount of time your spare tire will last depends on the type of spare tire that you have. Space Saver (or compact) spare tires are temporary and will only last 50-70 miles. Full-sized spare tires will last the same amount of time as normal tires (7-10 years)
Read on to find out how long spare tires last and what helps what affects their lifespan.
How Many Miles Do Spare Tires Last?
How many miles your spare tire lasts depends on its type (full-size or compact).
To answer the question of how many miles will a spare tire last, we first need to identify the common types of spare tires you may encounter.
There’s the space-saver tire, also referred to as a donut.
They’re easier to handle when you’re changing out a flat than a full-size tire because they’re so much smaller than regular tires.
They also have little tread and are usually pressurized to 60 pounds.
Compact spare tires are made out of thinner rubber than regular tires and therefore don’t have much endurance.
A space-saver spare tire’s only job is to safely get you to a location where you can get a new tire.
They should be replaced after you put 50 to 70 miles on them and should never be used as a daily driving tire.
When driving with a space-saver, do not exceed 50 miles an hour.
Space-saver tires affect a vehicle’s handling and because they’re thinner than a regular tire, they’re more vulnerable to punctures.
A matching full-size spare tire is identical in all ways to your other tires and will last 7 to 10 years.
To get an identical match, people typically buy 5 tires, using one as their spare.
They should also be included in your tire’s rotation schedule to even out wear.
You might also like: How Long Do Michelin Tires Last? (Explained)
What Happens If You Drive On A Spare Tire Too Long?
Driving too long on a space-saver spare tire can lead to a blowout or can even damage your transmission.
A space-saver spare tire is not a full-size tire and cannot be driven like one. A space-saver tire is only for temporary use.
Driving faster than 50 miles an hour on a donut can damage your transmission and puts you at risk of a blowout.
Compact spares don’t have any of the safety features regular tires do and don’t count on them for much help with braking or maneuvering.
Driving on a full-size spare that’s identical to your car’s tires gives you the same lifespan and mile limits they have.
How Many Years Do Spare Tires Last Unused?
An unused tire can last up to 10 years if it’s properly stored, but is only 100 % safe for up to 6 years, according to the National Highway Traffic Safety Administration (NHTSA).
Even when a spare tire is kept out of the weather and stored safely, it’s still exposed to the oxygen in air, which breaks down a spare tire from the inside and outside.
The rubber in tires contains oxygen-fighting compounds, but they can only slow the aging process.
Although some tires are filled with nitrogen to slow leakage over time and protect their rubber from oxygen degradation Consumer Reports indicates that while these claims are true, they’re not significant enough to warrant the expense.
Rubber also loses elasticity over time, leading to decreased traction.
Is a 20-Year-Old Spare Tire Safe?
A 20-year-old spare tire is not safe. Car manufacturers recommend replacing tires every six years, and no more than every 10 years, regardless of their remaining tread.
Driving on old tires has been the cause of accidents and fatalities.
It may seem logical to think an unused 20-year-old spare would be ok to drive, but it’s not.
The rubber materials that tires are made of decompose over time, whether they’re used or not.
As tires age, they become increasingly brittle, making them more likely to rupture, blow out, or go flat when placed under a load.
Should You Use A 10-Year-Old Spare Tire?
You can use a 10-year-old spare tire to get you where you’re going, as long as there are no visible signs of dry rot on the tire.
Dry rot is a form of tire deterioration caused by exposure to extreme weather conditions, harsh industrial chemicals, and ozone.
Dry rot causes tires to crack as the rubber materials in them become less elastic.
A 10-year-old spare tire should be replaced at the earliest opportunity.
How Long Do Compact Spare Tires Last?
Compact spare tires will last from 50 to 70 total driving miles.
They are smaller than a full-size spare tire and made of thinner rubber.
They wear out much faster and have little tread depth.
Compact spare tires, also called a donut or space-saver tires, are under more pressure than regular full-size spare tires, typically about 60 pounds of air pressure.
You should not drive faster than 50 miles per hour on a compact spare tire, or use it for longer than 50 to 70 miles.
The thin rubber of a compact spare tire makes it vulnerable to road damage.
You might also like: How Old Should New Tires Be? (Explained)
How Long Does A Full-Size Spare Tire Last?
A full-size spare tire will last as long as your regular tires, but just because it isn’t in daily use doesn’t mean it stays brand-new over time.
Spare tires age even when they are not used.
Oxygen degrades a spare tire just like your regular driving tires.
Ideally, you should replace a full-sized spare along with your other tires, every six years.
Final Thoughts: Spare Tire Lifetime
A spare tire’s lifetime depends on its type and condition.
A full-size spare tire has a safe lifespan of 6 years, but may be driven for up to 10 years, if it’s in good condition, without any visible signs of damage or dry rot.
A compact spare tire should be replaced after 50 to 70 miles, or after 8 years, whichever comes first.
Don’t accumulate more than 70 miles on any compact spare tire.
10 years is the upper age limit for any tire.
Check your spare tire’s air pressure once a month to make sure you’re not surprised the next time you need it.