Re: Highway speed with 12" wheels ??
The ST tire spec says 65mph at maximum pressure and load. Up to 75mph is allowed if the tire is running at a pressure 10psi higher than the load table indicates. In a few rare tires (Carlisle Marathon to name one) you are allowed to exceed the max pressure on the sidewall by 10psi to achieve this. None of them are rated for more than 75mph over long distances.
The speed rating is a matter of heat buildup in the tire carcass. Its fine to go faster for 30 seconds to pass and then slow back down. The heat won't build up enough to cause damage to a properly loaded/inflated tire over 1/2 mile.
The tires that come with Harbor Freight trailers these days ARE stamped 45 on the 8" and 55 on the 12" tires. That has nothing to do with the trailer tire specification though. They are just substandard tires trying to avoid lawsuits.
The ST tire spec says 65mph at maximum pressure and load. Up to 75mph is allowed if the tire is running at a pressure 10psi higher than the load table indicates. In a few rare tires (Carlisle Marathon to name one) you are allowed to exceed the max pressure on the sidewall by 10psi to achieve this. None of them are rated for more than 75mph over long distances.
The speed rating is a matter of heat buildup in the tire carcass. Its fine to go faster for 30 seconds to pass and then slow back down. The heat won't build up enough to cause damage to a properly loaded/inflated tire over 1/2 mile.
The tires that come with Harbor Freight trailers these days ARE stamped 45 on the 8" and 55 on the 12" tires. That has nothing to do with the trailer tire specification though. They are just substandard tires trying to avoid lawsuits.
