Heavy truck tires in Québec: the rules to know
Wear, damage, retreads, duals and pressure: what Québec regulations require for heavy vehicle tires, with the official sources.
The rules at a glance
These requirements come from section 120 of Québec’s vehicle safety standards regulation.
| Tread depth | At least 3.2 mm on a steer tire of a vehicle of 4,500 kg or more; at least 1.6 mm in other cases. A wear indicator must not touch the road. |
|---|---|
| Damage | No exposed ply or steel belt; sidewall cracks no deeper than 3.2 mm; no bulge or abnormal deformation. |
| Retreads | Not allowed on the steer axle of a vehicle of 4,500 kg or more, unless it has two steer axles. |
| Duals | The two tires must not touch, or differ in diameter by more than 13 mm. |
| Pressure | No more than 10% difference between tires on the same axle; never above the pressure on the sidewall, nor below the maker’s minimum. |
| Mixing tires | No different sizes, constructions or series on the same axle, unless the tire maker recognizes them as equivalent. |
| Repair and mounting | Following the tire maker’s standards. |
Major defect: the truck stays put
Under section 519.6 of the Highway Safety Code, no one may drive a heavy vehicle with a major defect on the applicable lists. For tires, this includes a flat, leaking or bulging tire. To move again, the tire must be repaired or replaced on site, or the truck towed.
Winter tires
The requirement to have tires designed for winter from December 1 to March 15 (Highway Safety Code, s. 440.1) does not apply to heavy vehicles. The wear, condition and pressure standards still apply all year.
Reading a tire size
In 11R22.5, 11 is the nominal width in inches, R means radial construction and 22.5 is the rim diameter in inches. In 295/75R22.5, 295 is the width in millimetres and 75 is the sidewall height as a percentage of the width.
On the same axle, do not mix different sizes, constructions or series unless the tire maker recognizes them as equivalent.
| Size | Where you see it |
|---|---|
| 11R22.5 | Tractors and trailers: one of the most common sizes. |
| 295/75R22.5 | Low-profile size common on tractors and trailers. |
| 275/80R22.5 | Tractors, straight trucks and trailers. |
| 11R24.5 | 24.5-inch rim, on some tractors and trailers. |
| 285/75R24.5 | Low profile on a 24.5-inch rim. |
| 445/50R22.5 | Wide-base single that replaces a dual pair. |
Inflating a truck tire safely
Québec’s workplace health and safety regulation requires a restraint device to inflate a tire mounted on the rim of a vehicle of 4,500 kg or more. Our technicians inflate tires in a cage or with a device designed for that purpose.
After a wheel replacement
Have the nuts re-torqued after 50 to 100 miles (80 to 160 km), as wheel and tire makers recommend.
General summary current as of November 7, 2026. It does not replace the official texts linked on this page.