Knowing the age of your tires is essential for vehicle safety, whether you’re inspecting a used car, checking your current set, or evaluating tires that have been in storage. Tires degrade over time even when they aren’t driven, and an old tire can fail without warning regardless of tread depth.
This guide explains how to find the tire manufacturing date, what the codes mean, when tires should be replaced based on age, and how to check tires on cars, trucks, SUVs, motorcycles, trailers, and RVs.
How Can You Tell How Old a Tire Is?
You can tell how old a tire is by reading the DOT code molded into the sidewall. The last four digits of this code indicate the week and year of manufacture: the first two digits show the week, and the last two show the year. For example, a tire with the code ending in 2319 was made in the 23rd week of 2019.
Understanding the DOT Tire Identification Number
The Department of Transportation requires every tire sold in the United States to carry a unique identification number molded into at least one sidewall. This code begins with the letters “DOT” and contains between 10 and 13 characters, depending on the tire and when it was made.
The DOT code identifies the manufacturing plant, tire size, manufacturer’s code, and the critical date code. Only the last portion of the DOT number tells you the tire’s age.
Where to Find the DOT Code
Look for a series of letters and numbers that begins with “DOT” on the tire’s sidewall. The code may appear on either the inboard or outboard side of the tire, so you may need to check both sides or turn the steering wheel to see it clearly.
On many vehicles, the DOT code is easier to read on the outer sidewall. If you can’t find it on the visible side, check the opposite sidewall by looking beneath the vehicle or removing the wheel if necessary.
Reading the Manufacturing Date Code
The date code is the final three or four digits of the DOT number, often set apart in a small oval or rectangular box. Tires made since the year 2000 use a four-digit code, while tires manufactured in the 1990s used a three-digit code with a different format.
For modern tires, the first two digits represent the week of the year (01 through 53), and the last two digits represent the year. A tire ending in 3522 was manufactured in the 35th week of 2022, which falls in late August or early September of that year.
Older Three-Digit Codes
Tires made in the 1990s have a three-digit date code. The first two digits indicate the week, and the third digit indicates the year within the decade.
A code ending in 328 means the tire was made in the 32nd week of 1998. Some manufacturers added a triangle symbol after the three-digit code to indicate the 1990s, distinguishing those tires from earlier decades, but this practice was not universal.
When Should Tires Be Replaced Based on Age?
Most tire manufacturers and vehicle makers recommend replacing tires that are six to ten years old, regardless of tread depth or visual condition. The rubber compounds in tires degrade due to heat, sunlight, ozone, and chemical reactions that occur even when the tire sits unused.
Major tire manufacturers including Michelin, Bridgestone, Goodyear, and Continental state that tires should be inspected annually after five years of service and replaced after ten years from the date of manufacture. Some automakers, particularly for high-performance vehicles, recommend replacement at six years.
Factors That Accelerate Tire Aging
Tires age faster in hot climates where high temperatures and intense sunlight exposure break down rubber compounds more quickly. Vehicles parked outdoors, especially in direct sun, experience more rapid tire degradation than those stored in garages.
Underinflation, overloading, and infrequent use also contribute to premature aging. Spare tires, trailer tires, and tires on RVs or seasonal vehicles often age out before wearing out because they accumulate few miles but experience years of environmental exposure.
Why Old Tires Are Dangerous
As tires age, the rubber loses flexibility and elasticity, leading to cracking, separation of internal layers, and reduced grip. These changes occur inside the tire structure where they aren’t always visible during a casual inspection.
Aged tires are more prone to sudden tread separation and blowouts, especially at highway speeds or in hot weather. Even if the tread depth meets legal minimums, an old tire can fail catastrophically without warning.
Checking Tire Age on Different Vehicles
Cars, Trucks, and SUVs
Inspect all four tires and the spare, as the spare may be significantly older than the tires in regular use. Many vehicle owners forget to check the spare until they need it, only to discover it’s unsafe due to age.
If you’re buying a used vehicle, check tire dates before purchase. Dealers and private sellers may install cheap or old tires to make the vehicle look road-ready without investing in quality replacements.
Motorcycles
Motorcycle tires typically have shorter service lives than passenger car tires due to their construction, compound, and operating conditions. Many motorcycle manufacturers and tire makers recommend replacement at five to six years regardless of mileage.
The DOT code on motorcycle tires appears in the same format and location as car tires. Check both the front and rear tire, as they often wear at different rates and may have been replaced at different times.
Trailers and RVs
Trailer and RV tires are especially vulnerable to age-related failure because these vehicles often sit for extended periods between uses. The tires experience load stress when in use but age continuously whether the trailer is moving or parked.
Many experts recommend replacing trailer and RV tires every five to seven years, even with minimal tread wear. Inspect the tires for sidewall cracking, weather checking, and discoloration, which are common signs of aging on infrequently used tires.
Signs of Tire Age and Degradation
Visual inspection can reveal age-related damage even before you decode the DOT number. Look for these warning signs that indicate a tire has deteriorated beyond safe use.
Cracking and Weather Checking
Small cracks in the sidewall or between tread blocks, called weather checking or dry rot, indicate that the rubber has hardened and lost its protective oils. These cracks appear as fine lines that may deepen into gaps over time.
Severe cracking is a clear sign that the tire should be replaced immediately, regardless of age or tread depth. The cracks create weak points where the tire can split or separate under load.
Discoloration and Fading
Tires naturally darken with age, but noticeable fading, uneven color, or a chalky appearance on the sidewall suggests advanced deterioration. Fresh rubber appears uniformly black or maintains the original sidewall color and finish.
Fading alone doesn’t make a tire unsafe, but combined with other age indicators it signals that replacement is approaching. Check the date code to determine whether the discoloration corresponds to an old manufacturing date.
Hardness and Loss of Flexibility
Press your thumbnail into the tire sidewall in an area without raised lettering. Fresh rubber will feel supple and resilient, while aged rubber feels hard and resists deformation.
A tire that feels rock-hard has lost the elastomer properties necessary for grip, shock absorption, and safe performance. This hardness increases the risk of impact damage, cracking, and poor traction.
What to Do If Your Tires Are Too Old
If you discover that your tires exceed the recommended age limit, prioritize replacement based on which tires show the most wear, age, or damage. All four tires don’t necessarily need replacement at once if some are newer, though matching axle pairs is important for handling and safety.
Consult your vehicle owner’s manual or the tire placard on the driver’s door jamb for the correct tire size, load rating, and speed rating. Purchase tires that meet or exceed these specifications from a reputable dealer or tire shop.
Buying New Tires
Check the date code on new tires before installation. Some retailers sell tires that have been in warehouse storage for a year or more, which reduces your effective service life.
Tires less than one year old from the manufacturing date are considered fresh, while tires one to two years old are acceptable if priced accordingly. Avoid purchasing any tire more than two years old as new, and never accept a tire more than three years old unless it’s significantly discounted and you understand the reduced service life.
Storing Spare and Seasonal Tires
If you store seasonal tires or carry a spare, keep them in a cool, dry, dark location away from electric motors, battery chargers, and ozone-producing equipment. Cover tires or place them in opaque bags to block UV light exposure.
Store tires upright if possible, or stack them horizontally if space requires. Avoid hanging tires for long periods, as this can distort the shape and stress the internal structure.
Checking Tire Age When Buying a Used Vehicle
Always inspect tire dates during a used car, truck, or motorcycle inspection. Replacing a full set of tires can cost several hundred to over a thousand dollars, depending on vehicle type and tire quality, so factor this expense into your offer if the tires are old.
Dealerships and private sellers may install the cheapest available tires to make a vehicle saleable. Even if the tread looks adequate, old tires represent a safety risk and an immediate expense for you as the buyer.
Negotiating Based on Tire Age
If the tires are more than six years old, request a price reduction equal to the cost of replacement, or ask the seller to install new tires before purchase. Use the tire age as a negotiating point along with any other deferred maintenance or needed repairs.
Get written estimates for tire replacement from local shops to support your negotiation. Sellers may not realize the tires are old or unsafe, so presenting the date codes and explaining the replacement recommendation can justify your request.
Professional Tire Inspection
While you can check tire age yourself, a professional inspection at a tire shop or service center can identify internal damage, improper wear patterns, and other issues that aren’t visible during a casual examination. Many tire retailers offer free inspections and will check tire age, pressure, tread depth, and condition.
Professional inspection is particularly important for tires on trailers, RVs, and vehicles that have been in storage, as these often develop hidden problems. Technicians can also verify that replacement tires meet the vehicle’s load and speed requirements.
Tire Age and Safety Inspections
Some states and jurisdictions include tire condition in vehicle safety inspections, though specific requirements vary. Even where tire age itself isn’t tested, visible cracking, exposed cords, or insufficient tread depth will result in inspection failure.
Consult your state’s department of motor vehicles or the inspection facility for current requirements. Proactively replacing old tires before inspection saves time and ensures you pass without delays or reinspection fees.
Maintaining Tire Records
Keep a record of when you purchase tires, including the date codes, brand, model, and size. This record helps you track service life and plan for replacement before tires become unsafe.
Include tire information in your vehicle maintenance log along with oil changes, brake service, and other regular maintenance. Knowing the installation date and expected service life helps you budget for replacement and avoid being caught off-guard by sudden tire failure.
Understanding the Six-Year Recommendation
The six-year replacement guideline represents a conservative approach based on typical driving conditions, climate, and tire storage. In hot climates or harsh conditions, tires may need replacement sooner, while vehicles in mild climates with garage storage may safely extend service to eight or even ten years.
Always prioritize visible condition and professional inspection over rigid age limits. A well-maintained seven-year-old tire showing no cracking or degradation may be safer than a poorly maintained four-year-old tire with visible damage, though both should be inspected and potentially replaced.
Tire Age for Commercial and Fleet Vehicles
Commercial trucks, fleet vehicles, and emergency vehicles often follow stricter tire replacement schedules due to safety-critical operations and liability concerns. Many fleets replace tires at five years regardless of tread depth to minimize roadside failures and downtime.
If you operate a commercial vehicle or fleet, consult your insurer, safety manager, and applicable DOT commercial vehicle regulations for tire age limits and inspection requirements. Record-keeping and documentation of tire replacement are often mandatory for commercial operations.
Final Recommendations
Check the DOT date code on all your vehicle’s tires today, including the spare. If any tire is six years old or older, schedule a professional inspection to assess condition and determine whether replacement is necessary.
Replace tires that show cracking, hardness, discoloration, or other age-related deterioration regardless of tread depth. Prioritize safety over extending tire life, especially for vehicles carrying passengers or towing trailers.
Continue learning about vehicle safety and maintenance by exploring more helpful articles on tire care, vehicle inspections, and automotive ownership topics.