Trailer Tires in Canada: ST Sizes and Load Range
Trailer tires are marked ST, for special trailer, in front of the size, as in ST225/75R15. They are built for trailer axles only: utility, boat, camper and cargo trailers. They are not meant for the steer or drive axles of a car or truck.
To pick the right tire, read the size moulded into the sidewall of the tire you are replacing, then match the load range letter (C, D, E and so on) or the load index to the trailer’s rating. When the old tires are unreadable, the trailer’s certification label gives the original size and load rating.
Choose your size below. Each size page lists the tires available to order, and you can narrow the list by brand.
Popular trailer tire sizes
Each size page lists every tire available in that size. For a trailer axle, choose tires marked ST (special trailer) on the sidewall.
Trailer tire questions
What does ST mean on a trailer tire?
ST stands for special trailer. A tire marked ST225/75R15 is designed for trailer axles. It is not intended for the steer or drive axles of a car or truck.
How do I find my trailer tire size?
Read the size on the sidewall of the tire you are replacing, for example ST225/75R15. If the tire is worn or unreadable, check the trailer’s certification label, which lists the original tire size and load rating.
What does the load range on a trailer tire mean?
The load range letter (C, D, E and so on) indicates the tire’s strength and relates to how much load it can carry at a given pressure. Match it, or the load index, to the rating on your trailer’s label rather than choosing by price alone.