Ontario G1 Test Coach
Safe drivingQuestion 325 of 328

When must you replace a tire because of tread wear?

  1. When the tread is less than 1.5 millimetres deep
  2. When the tread is less than 5 millimetres deep
  3. When the tire is one year old
  4. When the tread is 10 millimetres deep
Show answer

Correct answer: When the tread is less than 1.5 millimetres deep

Also replace tires when the wear indicators touch the road.

Source: The Official MTO Driver's Handbook (Ontario Ministry of Transportation), Maintaining your vehicle, Tires

Practice safe driving

Questions last reviewed: 18 October 2026