September 30, 2026 – PRESSADVANTAGE –
Tire rubber compounds degrade from age, heat, and storage conditions even when tread appears adequate, and manufacturer guidelines call for professional inspection or replacement well before tires reach the end of their usable life
IN N OUT Oil & Tires, which operates automotive service locations in Brampton, Woodbridge, and Mississauga, is reminding Ontario drivers that a winter tire with adequate tread depth is not necessarily a safe winter tire. As seasonal tire swap season approaches, the company says many drivers are pulling stored winter tires out of garages and basements without realizing that the rubber compound may have hardened past the point where the tire can perform as designed in cold weather conditions.
The issue centres on a widely misunderstood aspect of tire safety. Most drivers evaluate their winter tires by checking tread depth, often using the familiar toonie test recommended by the Tire and Rubber Association of Canada. If the tread reaches the bear’s paws on the coin, the tire passes. But tread depth measures only one dimension of tire condition. It does not reveal whether the rubber compound has lost the cold-temperature flexibility that makes a winter tire function differently from an all-season tire in the first place.
Winter tires are engineered with a softer rubber compound that remains pliable below 7 degrees Celsius, the threshold identified by the Canadian Automobile Association as the point where all-season tire compounds stiffen and lose grip. That pliability is what allows the tire to conform to road surface irregularities and maintain traction on cold pavement, packed snow, and ice. According to Michelin Canada, winter tires that are more than six years old may have a hardened compound that no longer performs effectively below 7 degrees Celsius, even when the remaining tread appears sufficient.
The degradation occurs whether the tires are on the road or in storage. Rubber compounds break down over time through a chemical process driven by exposure to oxygen, ozone, ultraviolet light, and temperature fluctuations. A set of winter tires stored in a hot garage through three Ontario summers will age differently than a set kept in a cool, dry basement, but both sets will lose compound flexibility over time regardless of how carefully they are stored.
The timelines that manufacturers and safety organizations recommend vary, but they converge on the same principle: tire age requires professional attention well before a tire wears out. Michelin Canada recommends professional inspection annually after five years of age and replacement at ten years from the date of manufacture regardless of remaining tread. Other manufacturers set a shorter window. According to the Tire and Rubber Association of Canada, several industry sources recommend replacement by six years from the manufacture date as a general guideline for passenger tires. The range reflects differences in compound formulation and intended use, but the common thread is that all of these timelines are shorter than many drivers assume, and none of them rely on tread depth as the deciding factor.
The challenge for drivers is that tire age is not obvious from a visual inspection. The manufacture date is encoded in the DOT (Department of Transportation) marking on the tire sidewall, but many drivers do not know how to read it. The last four digits of the DOT code identify the week and year the tire was produced. A code ending in 2019, for example, means the tire was manufactured in the 20th week of 2019, making it more than seven years old today. A tire purchased new in the fall of 2019 and used for six Ontario winters is approaching or past the six-year replacement window this season.
IN N OUT Oil & Tires says its technicians see this scenario regularly during seasonal tire swaps at all three locations. Drivers bring in a set of winter tires that look adequate on the surface, with tread depth above the 4.8-millimetre minimum recommended by the Tire and Rubber Association of Canada, but the sidewalls show fine cracking, the rubber feels noticeably harder than a newer tire, or the DOT code reveals the tires are well past the five-year mark where manufacturers recommend professional evaluation. In those cases, the technicians flag the condition and explain the options before proceeding with the swap.
The distinction matters for safety on roads across Brampton, Woodbridge, Mississauga, and surrounding communities. The region’s proximity to the Great Lakes creates conditions where temperatures can swing rapidly during the fall and winter months, and freezing rain, wet snow, and sudden cold snaps are common. A winter tire with adequate tread but a hardened compound may still channel water and slush through its grooves, but according to tire manufacturers, it will not grip cold pavement with the same effectiveness as a tire whose rubber is still pliable. According to the Canadian Automobile Association, the performance gap between winter and all-season tires is most pronounced in braking distance and cornering stability on cold and snow-covered surfaces.
Transport Canada advises against using winter tires worn close to 4 millimetres of tread depth on snow-covered roads because traction declines as the tread wears. The Ontario Ministry of Transportation suggests that all tires should be replaced when they reach 10 years of age or when tread depth falls below 1.5 millimetres, whichever comes first. But neither guideline addresses the compound changes that occur well before those thresholds, which is why manufacturer-recommended inspection and replacement timelines beginning at five to six years exist as a separate, age-based criterion.
Drivers who want to check their tire age before visiting a shop can find the DOT code on the tire sidewall. The full code may appear on only one side of the tire, so both the inner and outer sidewall may need to be checked. The last four digits are the manufacture date: the first two digits are the week, the last two are the year. A code ending in 4221 means the tire was made in the 42nd week of 2021.
IN N OUT Oil & Tires offers walk-in tire inspection at all three locations with no appointment required. Technicians check the DOT date code, measure tread depth, and inspect sidewall condition before any seasonal swap. The Mississauga location is at 20 Fairview Road East (905-279-7636), the Brampton location is at 11085 Creditview Road (905-495-4234), and the Woodbridge location is at 221 Trade Valley Drive (905-851-5566). All three are open Monday through Friday from 8 a.m. to 8 p.m., Saturday from 8 a.m. to 6 p.m., and Sunday from 9 a.m. to 5 p.m. Additional information is available at innoutoiltires.ca.
About IN N OUT Oil & Tires
IN N OUT Oil & Tires is a locally owned automotive service provider operating three locations in Brampton, Woodbridge, and Mississauga, Ontario. Founded in 2019, the company specializes in drive-through oil change services, tire sales and installation, seasonal tire swaps, brake service, battery replacement, and related vehicle maintenance. All three locations offer walk-in service seven days a week with no appointment required.
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For more information about IN N OUT Oil & Tires, contact the company here:
IN N OUT Oil & Tires
Will Alexander
(905) 495-4234
william@innoutoiltires.ca
11085 Creditview Rd, Brampton, ON L7A 0A8, Canada
