Trailer Tires

Special Trailer tires carry an ST prefix and they are built for a job no passenger tire is designed to do. A trailer tire does not steer and does not transmit power. What it does is carry a heavy vertical load and resist lateral sway, so ST tires use much stiffer sidewalls than a passenger or light truck tire of the same size. That stiffness is what keeps a trailer tracking straight behind the tow vehicle instead of swaying.Never fit passenger or LT tires to a trailer as a substitute. The softer sidewall flexes under the trailer load, which increases sway and builds heat, and heat is what destroys trailer tires. Most trailer tire failures are heat failures caused by underinflation or overloading rather than by road hazards.Trailer tire rules that prevent blowouts:Always inflate to the maximum pressure listed on the tire sidewall, not to a comfort pressureCheck pressure cold before every trip, since a trailer sits for weeks and loses airRespect the speed rating; many ST tires are rated to 65 mph and running faster builds fatal heatReplace on age, not just tread depth. Trailer tires typically age out at 3 to 5 years regardless of milesMatch load range to your loaded trailer weight with margin, and never round down