Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Recently I went to a chain tire shop/garage. My left rear tire had a bulge just above the hub cap. I looked online and it appears that this could be really bad if I didn't fix it.

So, the serviceman told me that I should replace the rear two tires so that the wear is even going forward.

He also checked my spare tire. He said that because my car is a 2003, the spare should be replaced. So he took my good right rear tire and put that in the spare tire compartment.

The spare was never used...why did I need to replace it? When do I need to replace my spare? If I didn't go to the my tires services, I would have never thought to replace the spare.

share|improve this question
up vote 8 down vote accepted

Rubber degrades over time, it looses flexibility, micro-cracks appear. When put under load the tire could fail catastrophically.

It is usually said that normal lifespan for a tire is ~6 years, after that it should be replaced (regardless of wear).

The structural integrity of a tire can degrade over an extended period of time. When that occurs, tires are more prone to catastrophic failure, which could, at best, cause an inconvenience, or, at worst, lead to a crash. The degradation of a tire occurs over time, mostly the result of a chemical reaction within the rubber components. That aging process can be accelerated by heat and sunlight.

Quoted from:

share|improve this answer
Your spare tire should have a significantly longer lifespan than your road tires even if you never drive because the biggest culprit in age-related decay is UV radiation from the sun. – Chuu Sep 22 '15 at 13:46

Tires have expiry dates.And when the expiry date comes, it does not necessarily mean that the tire will not perform but the quality lowers. This means that even if the tire is used on the car or the bike, its performance will be low and it will eventually wear out quicker than supposed. This type of tire can even put you at risk of accidents. This is the reason why you were advised to get a new spare tire. You should use your spare tire before it expires and always check the expiry date.

share|improve this answer
and how would a person determin the expiry date? – JerryOL Jan 31 '13 at 17:45
you can determine the age of a tire from the DOT code on the side. This is a legal requirement on tires sold in the US and common on tires worldwide. The last four digits are the week and year of manufacture - so 1314 would be the 13th week of 2014, or 24th-30th March 2014. see… – Colin Pickard Mar 26 '14 at 16:08

While most tires will require replacement before they achieve 10 years, it is advocated that any tires in service 10 years or more from the date of manufacture, including spare tires, be replaced with new tires as a simple precaution even if such tires appear service able and even if they have not made the legal wear limit.

share|improve this answer
If you'd like to post, we welcome it. Please do not include advertising in your posts, however. Thanks for your cooperation. – Pᴀᴜʟsᴛᴇʀ2 Oct 7 '14 at 13:26

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.