- Created: Wednesday, 25 May 2016 12:01
- Written by Westrans
Motor carrier regulations set minimum requirements for safe tire operation, including provisions for proper inflation and loading, minimum tread depth and safe tire condition. Compliance with these regulations does not guarantee safety but it significantly reduces the likelihood that a tire issue will cause a collision. Tire regulations fall primarily under Regulation 625 in Ontario. Similar regulations are established for other jurisdictions. Keep Your Vehicle Suspension in Alignment
In addition to potentially affecting safe control of the vehicle, improper alignment may wear down tires. Your maintenance plan should include tire/wheel/suspension alignment. Follow Industry Best Practices for Tire Management
Tire inflation should be checked at appropriate intervals during operation. There are many resources available to assist with proper tire management. Understand Tire Specifications
Tires are rated not only for size, but for maximum load, type of service and speed of operation. Tire specifications on a vehicle tire information label should be followed. Inspectors check for overloading of a tire’s sidewall capacity during roadside inspections when scales are available. Air Pressure
- 15 per cent under inflation in a tire equals approximately an 8 per cent decrease in expected tread mileage.
- 10 psi under inflation can cause a tire to wear out 20 per cent faster than normal.
- Tires can lose 3 psi per month due to air migration.
- Under inflated tires can run up to 5 degrees hotter for every psi of under inflation due to excessive flexing.
- Matching tire air pressures is critical in dual assemblies.
- A mismatch of 5 psi can change the tire circumference, and over 162, 000 km would be equivalent to dragging the under inflated tire 400 km.
- Each tread width size below the manufacturer’s recommended width reduces tread mileage by 10 percent.
- Across axles and between tandem axles, tread depths should be within 4/32".
- A left front steer tire wears faster than the right tire.
- On a set of dual tires, the tires should be less than 1/4" difference in diameter (less than 3/4" difference in circumference).