What Causes Uneven Tire Wear

If your tires are wearing unevenly, something is wrong and it is costing you money. Uneven wear shortens tire life, reduces grip, and can indicate a safety issue with your alignment or suspension. Ontario roads are particularly brutal on tire wear — our potholes, frost heaves, and construction zones knock alignment out and damage suspension components faster than in most provinces.

Inner or Outer Edge Wear: Alignment

If one edge of the tire is significantly more worn than the other, your wheel alignment is off. Negative camber (wheel tilting inward at the top) wears the inside edge. Positive camber wears the outside. This is the most common uneven wear pattern in Ontario because potholes knock alignment out regularly. An alignment check ($90 to $120) and correction ($120 to $180) fixes this. See our alignment guide.

Centre Wear: Overinflation

If the centre of the tread is worn more than the edges, your tires are overinflated. The excess pressure pushes the centre of the tread outward, creating a smaller contact patch in the middle. Check pressure against the recommendation on the driver's door jamb.

Both Edge Wear: Underinflation

If both edges are worn more than the centre, the tire is underinflated. The tread sags in the middle under the vehicle's weight, and the edges carry more load. This is common in winter when cold temperatures drop pressure. Check monthly and adjust.

Scalloped or Cupping Wear: Suspension

Wavy, scalloped patches around the tire indicate worn shocks or struts. The tire bounces slightly as it rolls, creating high and low spots in the wear pattern. Ontario's rough roads and potholes wear suspension faster. Shock and strut replacement runs $400 to $800 per axle including parts and labour.

One-Sided Wear on One Tire: Bent Component

If only one tire shows severe uneven wear, the steering or suspension component on that corner may be bent or damaged. A hard pothole hit can bend a control arm, tie rod, or wheel itself. This needs immediate inspection.

Prevention

Rotate tires every 8,000 to 12,000 km. Check alignment annually or after any significant pothole impact. Check pressure monthly. These three habits extend tire life by 20 to 30 percent and keep wear even.