What do I need to know about my horse trailer tires? 


A lot.  But don’t worry - it’s all manageable.  The most obvious reason to pay attention to your horse trailer tires is so that you don’t get a blowout and fly off the road - or worse.  The second reason is to save some dough.  Tires are expensive, and taking care of them properly extends their life.  Simple.  


Keep 'em check and keep 'em from rolling away. 


A few basics about horse trailer tires. 


  • Horse trailer tires are not the same as car and truck tires - they are ST tires, ST meaning Special Trailer.  You will also find P tires for passenger cars and LT for light trucks.  There’s rhyme and reason for this, I promise. 


  • ST tires for horse trailers are designed to support the trailer.  The are not attached to a drive train, so they are considered free rolling.  They need to have awesome traction for braking.  


  • These special tires also have stiffer sidewalls, and are more narrow than car or truck tires.  This helps create a smooth ride, and decreases the amount of sway that the trailer has.  You horse appreciates this.  


  • The tread on horse trailer tires will be more shallow than a car's tires.  This decreases the amount of wiggly action the tire has on the road, which lets the tire run cooler.  



Your trailer tires will tell you how much weight they can carry, and how to inflate them properly. 


  • Horse trailer tires blow out because they are under inflated.  This creates a lot of heat!  Proper inflation also gives you the best gas mileage for your rig. 


  • You also need to consider some wacky initials here.  The GVWR is the gross vehicle weight rating, AKA the maximum load your trailer can hold.  You may also find this total by calculating the GAWR (gross axle weight rating) and multiply it by the number of axels you have.  


  • Your tire’s rating must be the same or slightly more!  So if the GVWR is 7,500 lbs, you need tires at about 1,900 lbs.  for a trailer with four tires.  You also have to make sure the rim matches the tire!


So what do you need to do with your trailer tires?

  • Monitor the tire tread.  If you put a penny into the tread upside down, you should be able to see ALL of Lincoln’s head.  If any part of his head is covered up, the tires are considered bald and unsafe.  Check several locations on each tire. 



A penny can tell you if the tread is worn and needs replacement. 


  • Also make sure the tire tread is wearing evenly.  Tires that are under or over inflated will wear unevenly. 


  • Look for cracking of the tires.  You will see this where the rim meets the wall of the tire, and where there tread meets the wall of the tire.  Tires that are seldom used often crack easier than tires that see a lot of road action. 


  • Read the manual!  Your tires will actually tell you the best inflation.  And your trailer manufacturer can help you, also.  Some trailers have a chart on the trailer with pertinent information. 

  • Check the psi’s in the tires with a tire gauge!  Fill tires with air and remove air from tires when the tires are cold.  You can get a handy dandy tire inflator that attaches to your screw gun, that way, there’s no need to go to the gas station for air. 


It's ideal to cover all of the tires, and the spare, to protect them from UV light. Saves money!


  • Use tire covers to stop UV rays from damaging the tires, unless you have a garage to store your trailer in.  


Replace tires every three to five years anyway, even if they seem fine. 



How often do you inspect your trailer’s tires?