Tires should measure at minimum 3/32”, though anything under 6/32″ is less than ideal for driving. If you need to check your tread depth in a pinch, but don’t have a depth gauge you can use a traditional Canadian penny. All wheels of every motor vehicle and every trailer, while driven on a highway, shall be pneumatic rubber tires in safe operating condition, and free from bulges, cracks or cuts which penetrate to the cord that might render the tire hazardous; and each tire shall have in the case of tires on the steering axle or axles of trucks with a registered gross weight rating of over 4536 kilograms ( 10,000 lbs ), or buses, at least 3.2 millimeters ( 1/8 inches in fraction ); of tread remaining when measured by a tire tread wear indicator device, at three points on the circumference of the tire. Permissible upon a motor vehicle where required for safety. No regulations requiring or prohibiting the use of tire chains. Studded tires may be used from Oct. 1 to April 30. The law on studded tires can be viewed here. Individuals (not corporations) who are Manitoba Public Insurance customers can take advantage of the new Winter Tire Financing Program, which started this fall.