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Frequently Asked Questions


Below are answers to frequently asked questions. If you need additional information, please contact us



Carlisle Trailer Tires



Where are Carlisle tires made?

Depending upon which Carlisle tire you select, the tire could have been made in a U.S. factory or elsewhere.  We are an American company committed to American manufacturing and standards. 



Can I purchase tires direct from Carlisle?

Carlisle does not sell direct or offer our products for sale over the internet. Carlisle tires are sold to original equipment manufacturers and through distributors. To find a Carlisle dealer near you, please type in your zip code at:



What trailer tire do you recommend?

For best trailer performance, we suggest  the Carlisle Radial Trail RH (be sure to specify "RH" as that indicates the latest, new and improved model).  We find that many consumers are not aware of their trailer tire construction, either radial or bias ply, and may be running the wrong tire for their pattern of use.  For trailer tire best practices, please download the tips at:



What is the proper tire inflation?

Maintain air pressure at the maximum PSI recommended on the tire sidewall. It's best to check tire pressure with a quality tire gauge when tires are cold and in the shade.


Under inflation is the number one cause of trailer tire failure. An underinflated tire creates abnormal tire flexing and excessive heat causing:


  • Ride and handling problems
  • Decreased fuel efficiency
  • Reduction of tire life


Driving on tires with too much air is also not recommended. Over-inflated tires are more likely to cut, puncture or fail by sudden impact.



How do I determine the age of my trailer tires?

Every tire has a date code stamped on the sidewall, which is the date the tire was manufactured. The date code is usually at the end of the DOT I.D. and is a 4 digit number. The first two numbers indicate the week (out of 52) and the last two digits indicate the year. For example, 3409 means the tire was manufactured the 34th week of 2009. 


Please keep in mind that remaining tread is not an indicator of tire life as the irregular duty cycle requires that trailer tires sit in extended storage under static load conditions often for long periods without movement or maintenance causing the tire carcass (internal structure) to break down, a condition undetected by visual inspection.



What does “ST” mean?

Trailer tires are designated “ST” for “Special Trailer” tires. Trailer tire requirements differ greatly from automotive or light truck tires. Automotive tires are designated “P” for Passenger or “LT” for Light Truck and are not designed for trailer use. Passenger or truck tires, with their more flexible sidewalls, can result in trailer sway problems. The stiffer, heavy duty sidewalls of ST tires are designed to control and reduce sway problems. The construction, design, materials and testing used in “ST” tires meet the higher load requirements, duty cycles and special demands of trailering.



How fast can I travel on Carlisle trailer tires?

In the past, most trailer tires were rated at 62 or 65 mph. Today, some of our tires are "rated" (speed symbols) at 87 mph (N), some at 75 mph (L), some at 65 mph (J: ST tires) and some at 62 mph (J: non-metric tires).


Please remember that speed ratings are test speeds and not recommended driving speeds. The ratings apply only to the tire itself, and not  a particular vehicle. The speed rating does not mean that the vehicle can be safely operated at the tire's rated speed.


We recommend driving no more than 60 mph when towing a trailer. Please always drive at a safe speed and abide by the posted speed limit.



Is USA Trail a tubeless tire?

Yes - all of our USA trails are tubeless (TL).



Is it a good idea to install tubes in trailer tires?

Carlisle trailer tires are tubeless tires, meaning they don't require a tube. Our recommendation is that tubeless tires be used without tubes. We do not recommend that customers use a tube to "fix" a flat tire. Flat tires should be inspected and repaired (if possible) by a tire dealer.



Tube-type tires.

When using a tube-type tire, be sure to use the proper size tube, the proper flap and an appropriate wheel/valve stem style with a new tire.



I have two brand new Carlisle tires and two that are about 30% tread. Does it matter which tires are on the front or back axle?

Keep the new tires on the same axle and the two worn on the other. It shouldn't matter if they are positioned in the front or the back. But please keep in mind, that tires mounted on the rear axle are likely to wear faster than the tires on the front axle.



Where do I register my new tires?

The tire warranty registration form is on-line at:


What information do I need to register? For example, my tire side wall reads:



TWI AQ12 DOT AQB5 O512 means:


  • TWI: tread wear indicator, which is marked on the upper sidewall
  • AQ12: mold number
  • DOT: Department Of Transportation


Please register the information following the DOT mark which is "AQB5 0512".

  • AQ: Manufacturing plant code
  • B5: Manufacturer specific tire size code
  • 05: Production week
  • 12: Last 2 digits of the year of manufacture (2012)


There is room for 12 digits on the registration form but Carlisle only uses 8 digits.



Carlisle states that your trailer tires exceed DOT requirements.  What do you do to exceed DOT requirements?

Trailer tires are held to the FMVSS119 standard for DOT.  The endurance test under this standard is typically either 34 hours or 47 hours depending on the size of the tire.  The load during the test varies from 66% up to 114% per the DOT requirement.  Carlisle always extends the test after meeting the minimum endurance requirement for passing DOT by increasing the load to 130% and continuing the test.  Our standard production checks are set to meet approximately twice the mileage required by DOT on the endurance wheel.  We also have development standards that will exceed our standard production checks to insure that our product is robust enough so that we well exceed the DOT requirement at all times.



Should I choose 8 ply over 6 ply tires?

The 8 ply (Load Range D) will carry more load than the 6 ply (Load Range C) so it depends upon the weight of your trailer. Never exceed the maximum load rating stamped on the tire sidewall or the maximum vehicle load rating, whichever is less.



Trailer Tires Side Wall Specifications

The side wall of a trailer tire provides specific information regarding the size and style of the tire. For example,  ST175/80D13C means:


  • ST - Specialty Tires for trailer use only.


  • 175 - the maximum width of the trailer tire is approximately 175 millimeters at its widest point.


  • 80 - the height of the sidewall is 80% of the width, in this case 140 millimeters.


  • D (for diagonal) shows that this is a bias tire. The belts on this tire run diagonally from bead to bead or at about 45 degree angles to the center line of the tire. If your tire shows the letter R, your tire is a radial tire. The belts on this tire run radially from bead to bead or at 90 degree angles to the center line of the tire.


  • 13 indicates this tire fits on a 13 inch diameter wheel.


  • C is the load range.  Typically a "C" load range is equivalent to a 6 ply rated tire, "B" is a 4 ply, "D" is an 8 ply and "E" is a 10 ply rating.



Should trailer tires be rotated?

Trailer tires can be rotated when on a tandem axle to achieve move even wear across the set of tires.



Can trailer tires be plugged and patched?

A dealer may be able to repair a trailer tire with a puncture. Some tires are not repairable based upon the size and location of the puncture.



I’ve heard that your Radial Trail RH tire is the best. Is that technology used in the Sport Trail as well?

The Radial Trail RH is a radial ply tire. The Sport Trail is a bias ply tire. The tires use different technologies to achieve performance. Carlisle has had great success with both of these product lines.



What is the maximum psi limitation for your trailer wheels?

Max air capacities are typically a function of the tire, not the wheel. Unlike tires, the load rating of a wheel is not generally dependent on the operating pressure. The wheels themselves are manufactured and tested to a load rating (without consideration of pressure) and can safely support that load. As long as the load is within the limits of our wheel's load rating in pounds, our product will perform as expected.




Carlisle ATV/UTV Tires


What is the recommended tire pressure for normal operation?

Please refer to the Vehicle Owner's Manual or the specifications sticker on the vehicle for correct inflation pressures for the tires. A quality tire gauge should be used and the pressure should be taken "cold", when the tire has not been in service for any extended length of time.


Should I use a different ATV tire for the front and rear?

We don't have any distinction for tires with regards to front/rear or left/right.  Typically, you might use a more narrow tire on the front of an ATV than the rear.  For instance, 25x8-12 on the front and 25x10-12 on the rear.  This is done to enhance steering capability.


What is the difference between Ply Rating and Star Rating?

A “Ply Rating” is a measure of the tire’s strength and is shown on many types of tires, including utility vehicle tires.  A “Star Rating” is a measure of inflation pressure and is typically used on “AT” or ATV tires.  There is no direct conversion between the two systems since they depict different values (strength vs. inflation).


STAR Rating System: A Star Rating indicates the maximum operating pressure for that tire. The Japan Automobile Tyre Manufacturers Association, Inc. (or JATMA) used kilopascals to measure tire inflation pressures.  Due to the conversion difficulty to psi (1 Kpa = 0.14503773020923 psi), the Star Rating system began as an indication of the “Maximum Operating Pressure”.


A 1 Star (*) tire has a “maximum operating pressure” of 4 PSI.

A 2 Star (**) tire has a “maximum operating pressure” of 5 PSI.

A 3 Star (***) tire has a “maximum operating pressure” of 7 PSI.


The US Tire & Rim Association (TRA) adopted this identification system several years ago only for “AT” marked tires.  “AT” tires are labeled in the size description of ATV tires and are identified as having an operating condition at or below 7 PSI.  ATV tires typically have a Star Rating, not a Ply Rating.


PLY Rating System: The Ply Rating system provides a strength index.  Ply Rating is widely used by many classes of “off-highway” service tires. Years ago, a tire’s construction was rated by the number of plies (or layers) within the carcass. This rating system was used when less durable textile (such as cotton) was used to create the tire carcass. Because the material was less durable, it took more layers of bonded, fused material to increase the tire’s strength and longevity. However, with the advent of new technologies and materials, a tire can be constructed with only a few (2 or 3) plies of material, yet have the same strength and longevity of a 6- or 7-ply tire. Hence, a new 25x8.00-12 tire may have a 6-ply construction rating when set at 36 psi, yet be constructed with only a couple of layers.