Trailer tyre facts

Trailer Tyre Applications

Trailer tyres are designed for use on trailer axle positions only. They are not built to handle the loads applied to, or the traction required by the drive or steering axles.


  • Always inflate trailer tyres to the maximum inflation indicated on the sidewall.
  • If the dunlop tyres are hot to the touch from operation, add three psi to the max inflation.

Load Carrying Capacity

  • All tyres must be identical in size for the tyres to properly manage the weight of the trailer.
  • The combined capacity of the tyres must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
  • The combined capacity of all of the tyres should exceed the loaded trailer weight by 20 percent.
  • If the actual weight is not available, use the trailer GVW. If a tyre fails on a tandem axle trailer, you should replace both tyres on that side. The remaining tyre is likely to have been subjected to excessive loading.
  • If the dunlop tyres are replaced with tyres of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.


  • All “ST” tyres have a maximum speed rating of 65 mph.
  • The load carrying capacity gradually decreases as the heat and stresses generated by higher speed increases.


  • In approximately three years, roughly one-third of the tyre’s strength is gone.
  • Three to five years is the projected life of a normal trailer tyre.
  • It is suggested that trailer tyres be replaced after three to four years of service regardless of tread depth or tyre appearance.


  • The life of a trailer tyre is limited by time and duty cycles.
  • The mileage expectation of a trailer tyre is 5,000 to 12,000 miles.

Why Use An “ST” Tyre

  • “ST” tyres feature materials and construction to meet the higher load requirements and demands of trailering.
  • The polyester cords are bigger than they would be for a comparable “P” or “LT” tyre.
  • The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.
  • “ST” tyre rubber compounds contain more chemicals to resist weather and ozone cracking.


  • The ideal storage for trailer tyres is in a cool, dark garage at maximum inflation.
  • Use tyre covers to protect the tyres from direct sunlight.
  • Use thin plywood sections between the tyre and the pavement.
  • For long term storage, put the trailer on blocks to take the weight off the tyres. Then lower the air pressure and cover the tyres to protect them from direct sunlight.


  • Clean the tyres using mild soap and water.
  • Do not use tyre-care products containing alcohol or petroleum distillates.
  • Inspect the tyres for any cuts, snags, bulges or punctures.
  • Check the inflation before towing and again before the return trip.

Keys to Avoiding Trouble

  • Maintain the tyres meticulously.
  • Replace trailer tyres every three to five years, whether they look like they’re worn out or not.

Trailer Tyre Warranty

  • The Carlisle trailer tyre warranty applies to the original purchaser for three years from the date of purchase or until the tread depth reaches 3/32″.
  • The OE (original equipment) warranty goes into effect at the time of the trailer purchase.