Are Your Tires Too Old to Be Safe?

Even if they don’t wear out from use, our tires are aging out due to the simple fact that the components used in their manufacture doesn’t last forever.

We once compared a brand-new set of Vredestein Sprint Classic tires against a set of never-used Michelin X tires–the catch, of course, being that the Michelins had spent 32 years in dry storage. Our testing, done on a Triumph TR6, included both an emergency lane change maneuver as well as braking from 60 mph.

The Vredestein tires felt neutral during the emergency lane change maneuver while delivering safe, confident stops. The old tires? They were downright scary: snap oversteer when asked to change lanes while requiring 20 extra feet to stop from 60 mph. That can easily be the difference between life and death.

How old is too old for a tire? Our friends at Tire Rack offer this advice:

Our experience has been that when properly stored and cared for, most street tires have a useful life in service of between six to ten years. And while part of that time is spent as the tire travels from the manufacturing plant to the manufacturer's distribution center, to the retailer and to you,the remainder is the time it spends on your vehicle.”

So, a follow-up question: How old are the tires on your classic?

Tire Rack again offers this handy advice:

Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the two digits used to identify the year.”

In their example, a tire marked with DOT U2LL LMLR 5107 was built during the 51st week of 2007.

If your tires were built before 2000, then Tire Rack offers this information:

The Tire Identification Number for tires produced prior to 2000 was based on the assumption that tires would not be in service for ten years. While they were required to provide the same information as today's tires, the week and year the tire was produced was contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year.”

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Comments
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David S. Wallens
David S. Wallens Editorial Director
2/28/20 2:15 p.m.

So, a PS to this topic: We just did some more old-tire testing using our 1984 Porsche 911 Carrera. The old tires have been tested, and the new ones installed. After we retest, we'll share the results.

Here's a sneak peek. 

bartjr1
bartjr1 New Reader
3/2/20 12:26 p.m.

The problem may even be worse than the article mentions - especially for cars that sit idle for long periods of time (think winter). During road use, centrifugal forces present in the tires helps keep the chemicals in  the tires distributed throughout the rubber. When sitting idle, those chemicals embedded in the outer surface evaporate naturally, while the internal rubber loses little. Very old tires began to crack on their outer surface which is of course a function of age, but tires that would otherwise have some life left based on their age, deteriorate much faster if they just sit. This is even further exacerbated when vehicles are left outside during dry, cold winter weather.

Other than a "trailer queen" used strictly for shows, there is no justification for keeping old rubber on a classic car. As an added bonus, when you refresh the tires with new, you gain the tremendous improvement in tire construction and technology. Small, lightweight sports cars from the mid-20th century do not even begin to challenge the capability of modern tires.

RadBarchetta
RadBarchetta New Reader
3/2/20 2:04 p.m.

If your tires don't have the modern date code, i.e. they were made before 2000, you need not bother asking if they are too old. The answer will always be yes.

David S. Wallens
David S. Wallens Editorial Director
3/2/20 4:33 p.m.

In reply to RadBarchetta :

Very much yes.

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