5 Signs You Need New Tires
Learn the 5 warning signs that your tires need replacing. From tread depth to sidewall cracks, know when it's time for new rubber.
· 3 min read · By Driveway Tire
1. Low tread depth
Tread depth is the most straightforward indicator of tire health. New tires typically start with 10/32" to 11/32" of tread. The legal minimum in Ontario is 1.5 mm (about 2/32"), but traction drops off well before that — most experts recommend replacing tires at 4/32" for winter use and 3/32" for summer. The easiest check is the built-in tread wear indicators: small raised bars inside the tread grooves. If the tread surface is level with these bars, the tire is at the end of its safe life. For an exact reading, a tread depth gauge from any auto parts store takes seconds.
2. Sidewall cracking or dry rot
The sidewall is the smooth area between the tread and the rim. Over time, UV exposure, ozone, and temperature fluctuations cause the rubber to dry out and crack. These cracks — sometimes called dry rot or weather checking — weaken the tire's structural integrity. Small surface cracks are cosmetic, but deeper cracks that expose the cords underneath are a safety concern. Tires stored outdoors, in direct sunlight, or in unheated garages are more prone to cracking. If you see cracks wider than 1 mm or any cracking that goes deep into the rubber, it's time to replace.
3. Bulges or blisters
A bulge or blister on the sidewall means the internal structure of the tire has been damaged, usually from hitting a pothole, curb, or debris at speed. The impact breaks the internal plies, allowing air pressure to push the rubber outward. A tire with a sidewall bulge cannot be repaired and should be replaced immediately — it's at risk of a blowout, especially at highway speeds. Ottawa's spring potholes are a common cause, so it's worth checking your sidewalls after winter.
4. Vibration at highway speed
Some vibration is normal on rough roads, but a consistent shimmy or vibration through the steering wheel at highway speeds (80+ km/h) can indicate a tire problem. Common causes include a shifted belt inside the tire, uneven wear from misalignment, or a tire that's gone out of balance. If rebalancing doesn't fix the vibration, the tire itself may have internal damage. Persistent vibration also accelerates wear on suspension components, so it's worth diagnosing early.
5. Age — even with tread remaining
Tires degrade from age regardless of how much tread is left. Rubber compounds break down over time from oxidation, even on tires that are barely driven or stored indoors. Most tire manufacturers recommend replacing tires that are 6 to 10 years old, regardless of tread depth. You can find the manufacture date on the tire sidewall — look for the DOT code, where the last four digits indicate the week and year of production (e.g., '2219' means the 22nd week of 2019). If your tires are approaching the 6-year mark, have them inspected closely during your next swap.
We check during every swap
Every time we swap your tires, we do a visual inspection of tread depth, sidewall condition, cracking, and wear patterns. If we spot anything that needs attention, we'll let you know on the spot — no upsell, just honest information so you can plan ahead. Catching tire issues early gives you time to shop for replacements rather than dealing with an emergency.