Are Your Tires Ready To Be Replaced? Here’s Exactly How To Tell

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A fresh set of tires make a noticeable difference to the way your car rides, handles and grips. But as they wear out, the incremental deterioration is hard to notice. That’s why it helps to know how to tell exactly when your tires are ready for replacement.

Tread Wear Indicators

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Every tire has small rubber protrusions between its treads. These aren’t very noticeable when the tire is new, but as the treads wear down, the become more prominent. Once the tread depth is flush with these tread wear indicators, its time for a new tire. Most tread wear indicators are 2/32 inches high.

The Penny Test

Inspecting The Wear Of A Balding Tire Tread Using a Penny
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Another way to check tread depth is by using the ‘penny test’. Insert the penny between the tire tread and if you can see all of Lincoln’s head, the tread depth is below 2/32 inches. This is a useful trick if you want to check the tread across the tire width.

State Laws Regarding Tread Depth

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While a tread depth of 2/32 inches is generally considered the minimum legal limit, it differs from state to state. California and Idaho, for example allow you to have a 1/32-inch tread depth, while some others require no less than 4/23 inches on the front tires.

Wet Weather Grip

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Tire tread depth has a marked effect on your vehicle’s braking, cornering and acceleration capabilities. If you regularly drive in snow, mud or wet weather, a tread depth of 2/32 inches may not be safe enough.

If you notice the Vehicle Stability Control (VSC) warning light flashing when you accelerate away from the lights, or if your car slides easily under braking or cornering, the tread depth may not be deep enough to keep enough of the tire’s contact patch on the road surface.

Uneven Tread Wear

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New tires have approximately 10 to 12/32-inch tread depth. However, too much or too little tire pressure, damaged suspension components and poor alignment can result in uneven tread wear which can result in little to no tread on certain sections of the tire, making it illegal and unsafe.

Underinflated or badly aligned tires can wear on the inside edge, something that is difficult to spot without looking underneath the vehicle. Overinflated tires can wear out the center section of tread, while regular hard cornering will show excessive wear on the outside edges.

Handling Feel

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If your car suddenly starts to feel unpredictable or sloppy around corners, the tires may be at fault. In most cases, a tire’s grip and handling capabilities decrease gradually, so a sudden change can indicate a damaged tire or wheel.

Tire Age Limits

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Tires have a whole host of numbers and letters on their sidewalls. These give you information like tire size, load index, traction rating and manufacture date.

This last figure is shown as a set of four numbers. The first two are the week of manufacture, the second two indicate the year. So, 1721 shows that the tire was made in the 17th week of 2021.

There is no specific law on how old a tire can be, but most manufacturers recommend at most 5 years between changes regardless of the mileage covered. This is because the tire compound breaks down over time, becoming hard and brittle.

Sidewall Cracks

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Excessive sun exposure, age and overloading can result in hairline cracks on a tire’s sidewalls. This can result in pressure loss and eventually a blowout. Tires on vehicles kept in garages and not exposed to extreme weather conditions tend to last for longer before developing sidewall cracks.

Tires Not Keeping Pressure

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As a tire ages, it can start to develop leaks, while this may be due to faulty valves, it can also be caused by damaged tire beading or cracked wheels. Don’t just keep topping up a leaking tire, get it checked before you suffer a blow out. While you may not initially notice it, underinflated tires can also increase your gas bills.

Hard Ride

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The rubber compound in tires becomes hard and brittle over time. If your car feels overly harsh over bumps, the tires may not be supple enough to absorb the impact anymore. Check the tire manufacture date and if it is over 5 years, the tires may be ready for a change.

Tire Damage

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Some types of tire damage like surface cuts or broken sections of tread are easy to spot. But a sidewall bubble or abrasion that occurs on the inside section of the tire can go unnoticed until it is too late. A damaged tire beading can also be hard to see, so keep an eye out for sudden losses of tire pressure or a shaky steering wheel. It is also good practice to regularly check the tires on both sidewalls and the tread surface.

Stay Safe and Replace Your Tires in Time

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As a general rule you should always buy the best quality tires you can afford, cheap tires are cheap for a reason. Always buy the right size and weight rated tire for your vehicle. To help extend the life of your tires, make sure they are properly inflated and avoid harsh acceleration and braking.

Author: John Tallodi

Title: Freelance Motoring Journalist

Expertise: Classic and modern cars

Bio:

John is an avid gear head who spends most of his time either reading, writing, driving or fixing cars. He has worked for several automotive media outlets over the years on everything from obscure classic cars to modern machinery and the latest in EV tech. While he loves just about anything on four wheels, he has an overriding passion for '80s and '90s cars which stems from a childhood absorbing car magazines from this era.