ShareThis Page

Tires past certain age pose risks

| Friday, Dec. 27, 2013, 8:57 p.m.

Question: I just saw a news story on TV that said many people are driving on old tires and they can be dangerous. I didn't get to a pencil and paper quick enough to write down the way to check the numbers on my tires. Can you please explain more about this?

— Jessica K.

Answer: Research indicates the likelihood of tire failure increases considerably after approximately six years of age. With the tread life of a modern tire lasting far longer than those of the past it's common to encounter tires that are beyond the six to ten year recommended lifespan. RVs, trailers and classic cars are especially likely to wear older tires as they are slow to rack up a lot of miles. One may also find a new tire that's actually several years old, still on the shelf, before being purchased. In the case of low production/exotic tires or those made overseas, it's not unusual to find a new tire that's already a year old.

While exposure to sunlight, ozone, and heat accelerate aging, even spare tires and those in storage seem to be similarly affected. Visible small cracks in the sidewall are an indicator of aging, although deterioration can occur internally and isn't readily detectable. Quite a few vehicle manufacturers recommend tire replacement at six years, regardless of remaining tread, and while some tire manufactures say 10 years is the maximum life one should expect, they play it safe and recommend you follow the vehicle manufacturer's recommendation (likely six years). A common recommendation is to have tires five years old or older inspected annually.

Here's how to read when a tire was made: Look for the tire identification code on the sidewall, containing between ten and twelve digits. It's usually found close to the tire/wheel intersection and is preceded by the abbreviation DOT. The code lists the manufacturing location, tire size, manufacturer's code, and the week and year the tire was manufactured. You may need to check both sides of the tire as the full DOT code containing the final three or four digits (date) may be branded only on one side. Tires made since 2000 use the final four digits to indicate the week and year it was built. For example 1505 means the 15th week of 2005.

The most important thing a vehicle owner can do to enhance safety and fuel economy is to regularly check and maintain correct tire inflation pressure. Low tire pressure wastes fuel, causes tire overheating and reduces wet weather traction. Tires should be checked when cold and one can find the recommended pressure on a sticker on the driver's door or door pillar. Don't use the maximum pressure found on the tire as this won't be appropriate for your particular vehicle. Also, buy your own gauge rather than trust the beat-up one on the end of the filling station hose.

When a tire requires repair due to a nail or screw puncture, insist on having the tire dismounted, inspected, and the puncture plugged and patched. A quickie and cheap plug insertion from the outside, while commonly done, is not an appropriate repair.

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at

TribLIVE commenting policy

You are solely responsible for your comments and by using you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.