Trailer Tire Guide

Updated June 2026

If you’re towing anything — a boat, a camper, a livestock trailer, a utility trailer hauling equipment out to a job site — your trailer tires are the most overlooked safety component on the rig. They carry static loads, generate more heat than vehicle tires, and spend long stretches parked in the sun between uses. Getting them right matters.

This guide covers everything you need to make a confident trailer tire decision: the difference between ST and LT tires, radial vs. bias-ply construction, how to read ST sizing codes, ply ratings and load ranges, top tire picks, and a maintenance schedule to protect your investment. The size, load index, and speed rating reference charts are further down the page.

Take Off Tire has been Lincoln’s trailer tire resource since 2015. We stock radial and bias-ply options across all common ST sizes, and our team can answer load and fitment questions before you buy. Call us at 402-413-6646 or visit our Trailer Tire page for more information on trailer tires and tire recommendations.

Types of Trailer Tires - Radial vs. Bias-Ply

Radial Trailer Tires

Radial tires have steel belts running perpendicular to the direction of travel, topped with stabilizing belts. This gives the tread and sidewall independent functions — the tread stays flat and stable under load while the sidewall flexes to absorb road imperfections.

  • Longer tread life due to less heat buildup
  • Smoother, more stable ride at highway speeds
  • Better resistance to flat-spotting during storage
  • Recommended for any trailer regularly driven at 55+ mph

Bias-Ply Trailer Tires

Bias-ply tires have cords running at a diagonal angle (typically 30–45°) across the tire from bead to bead. This creates a stiffer, more interconnected sidewall and tread.

  • Lower purchase price — often 20–30% cheaper than radial equivalent
  • Stronger sidewall — good for rough terrain, rocky roads, and off-road use
  • More resistant to punctures from sharp debris
  • Best suited for low-speed applications: boat trailers, farm equipment, utility trailers on gravel or field roads

In Nebraska, bias-ply tires are a reasonable choice for trailers that stay on county gravel roads, ag fields, or job sites at low speeds. For anything running I-80 or Highway 2 at highway speed, invest in radials.

How to Read an ST Tire Size

ST trailer tire sizes follow a specific format. Here’s how to decode a common example — ST235/80R16E:

ST 235 80 R 16 E
Special Trailer Section width (mm) Aspect ratio (% of width) Radial construction Wheel diameter (inches) Load Range (ply equiv.)

The Load Range letter at the end (C, D, E, F, G) tells you the tire’s ply rating equivalent and maximum load capacity. Higher letter = more capacity. For most utility and travel trailers, Load Range D (8-ply) or E (10-ply) is appropriate. Heavy-duty equipment trailers may require Load Range F or G.

Ply Ratings and Load Ranges

“Ply rating” is an older term still widely used. Today’s tires use Load Range letters, but the equivalency is straightforward:

Load Range Ply Rating Equiv. Max PSI (typical) Common Application
C 6-ply 50 psi Small utility, boat trailers
D 8-ply 65 psi Most utility & cargo trailers
E 10-ply 80 psi Travel trailers, fifth wheels
F 12-ply 95 psi Heavy equipment, livestock trailers
G 14-ply 110 psi Extra heavy-duty commercial

Important: Never downgrade your load range from what your trailer manufacturer specifies. Upgrading one load range (e.g., C to D) is generally acceptable and adds margin — downgrading is not.

Trailer Tire Maintenance

Trailer tires fail more often from neglect than from age or mileage. They sit for long stretches under load, exposed to UV and temperature swings, often without the daily attention that vehicle tires receive. A consistent maintenance routine dramatically extends their life and prevents roadside failures.

Tire Pressure

Trailer tires should be inflated to the maximum PSI shown on the tire sidewall — not a lesser figure like passenger tires. Because trailer tires carry static weight rather than steering and acceleration loads, they need full pressure to carry their rated capacity without excessive sidewall flex and heat. Check cold pressure before every trip.

Balancing

Unbalanced trailer tires cause vibration that accelerates tread wear unevenly and puts stress on wheel bearings and suspension components. Most trailer owners skip balancing — don’t. A balanced trailer rides better behind the tow vehicle and the wheel bearings last significantly longer. Take Off Tire balances trailer tires as part of any new tire installation.

Rotation

If your trailer has tandem axles, tire rotation is straightforward: swap front and rear tires on the same side, following the same interval you’d use for vehicle tires (every 5,000–7,500 miles). Periodically checking for uneven wear patterns will alert you to alignment issues before they become expensive.

Visual Inspection

Before every trip, check for: sidewall cracking or crazing (UV and ozone damage), embedded objects in the tread, bulges or bubbles in the sidewall, and tread depth. Sidewall cracks that penetrate deeper than a surface check — where you can see the cords — are grounds for immediate replacement.

Storage

When the trailer is parked for extended periods, UV exposure degrades rubber even faster than mileage does. Use tire covers if storing outdoors. Consider placing blocks under the axle to relieve pressure from the tire contact patches — this prevents flat-spotting and reduces sidewall cracking at the bead area.

Trailer Tire Safety

The consequences of a trailer tire failure at highway speed are serious — loss of control, trailer sway, cargo damage, and risk to other drivers. Most blowouts are preventable.

Visual Inspection

Overloading is the leading cause of trailer tire failure. Your tire’s load index tells you the maximum capacity per tire at full inflation. Multiply by the number of tires for total rated capacity. Your trailer’s GVWR should fall within that number — with margin. If you’re unsure of your actual loaded weight, most truck stops and grain elevators in Nebraska have drive-on scales.

Respect the Speed Rating

Most ST trailer tires are rated L (75 mph) or N (87 mph). These ratings assume ideal conditions: proper inflation, correct load, moderate ambient temperature. In Nebraska summer heat on I-80, building in a 10–15 mph buffer below the rated maximum is a reasonable safety margin. Never exceed the speed rating.

Don’t Ignore Age

Regardless of tread depth, most tire manufacturers recommend replacing trailer tires at 5–6 years from the manufacture date (found in the DOT code on the sidewall — the last four digits indicate week and year). Rubber compounds degrade from the inside out. A tire that looks fine at 7 years old may be structurally compromised.

What to Do After a Blowout

If a trailer tire blows, hold the tow vehicle steering wheel firmly and do not brake hard. Gradually reduce speed and guide the trailer to a safe stop off the road. Do not drive on a blown tire. If you’re on an Interstate and need assistance, Take Off Tire provides commercial tire service — call 402-413-6646.

Trailer Tire Size Chart

The most common wheel sizes for trailer tires are going to be 15 and 16 inches. For this size wheel, the most common tire sizes include: ST205/75R15, ST225/75R15, ST235/80R16 and ST235/85R16. These sizes increase in both diameter and width and as they get larger the ply rating of the tire also increases. The tire options in 15 inch will range from 6 ply to 12 ply. The tire options for 16 inch will range from 10 ply and go up to 14 ply for extra heavy duty applications.

Wheel sizes are not limited to 15 and 16 inches. There are plenty of applications for smaller wheels such as 13 and 14 inches for smaller trailers such as boat trailers and light duty equipment trailers. The most common tire sizes for 13 and 14 inch trailer wheels include: ST175/80R13, ST185/80R13, ST205/75R14 and ST215/785R14. There are also many applications out there for trailer wheels smaller than 13 inches ranging as small as 8 inches through 12 inches. Heavy duty trailers will have 17.5 and 19.5 inch wheels and commercial trailers that will have 22.5 and 24.5 inch wheels.

Trailer Tire Speed Rating Chart

Your tire’s speed rating is located at the end of the tire size code (ST22575R15 117/112N – N is the speed rating). This letter represents the maximum speed the tire is certified to carry under the load it is rated for, while properly inflated and under ideal driving conditions.

It is very important to keep your trailer tire’s speed rating in mind, especially if you regularly drive your trailer at highway speeds. For example, a trailer tire with a speed rating “L” is rated for speeds up to 75mph (under ideal conditions). Driving 80mph with an “L” rated tire puts your tire at a higher risk of overheating and failing. 

Speed RatingMaximum Speed
JUp to 62 MPH
KUp to 68 MPH
LUp to 75 MPH
MUp to 81 MPH
NUp to 87 MPH

Trailer Tire Load Index Chart

Your tire’s load index is located at the end of the tire size code (ST225/75R15 117/112N – 117/112 is the load index). Trailer tires have 2 numbers listed. The higher number is the weight supported for single wheel applications. The lower number is the weight supported for dual wheel (2 tires per side) applications. These numbers represent the maximum weight a single tire is certified to carry when inflated to its maximum rated pressure, under ideal driving conditions.

Take your trailer tire’s load index and multiply by your trailer’s total number of tires (generally 2 or 4) to find the total weight your tires are rated to carry.

Load IndexLoad Capacity (lbs)Load IndexLoad Capacity (lbs)Load IndexLoad Capacity (lbs)
70739 1001764 1304189
71761 1011819 1314289
72783 1021874 1324409
73805 1031929 1334541
74827 1041984 1344674
75852 1052039 1354806
76882 1062094 1364938
77908 1072149 1375071
78937 1082205 1385203
79963 1092271 1395357
80992 1102337 1405512
811019 1112403 1415677
821047 1122469 1425842
831074 1132535 1436008
841102 1142601 1446173
851135 1152679 1456393
861168 1162756 1466614
871201 1172833 1476779
881235 1182910 1486844
891279 1192998 1497165
901323 1203086 1507385
911356 1213197
921389 1223307
931433 1233417
941477 1243527
951521 1253638
961565 1263748
971609 1273858
981653 1283968
991709 1294079
Load IndexLoad Capacity (lbs)
70739
71761
72783
73805
74827
75852
76882
77908
78937
79963
80992
811019
821047
831074
841102
851135
861168
871201
881235
891279
901323
911356
921389
931433
941477
951521
961565
971609
981653
991709
1001764
1011819
1021874
1031929
1041984
1052039
1062094
1072149
1082205
1092271
1102337
1112403
1122469
1132535
1142601
1152679
1162756
1172833
1182910
1192998
1203086
1213197
1223307
1233417
1243527
1253638
1263748
1273858
1283968
1294079
1304189
1314289
1324409
1334541
1344674
1354806
1364938
1375071
1385203
1395357
1405512
1415677
1425842
1436008
1446173
1456393
1466614
1476779
1486844
1497165
1507385

Take Off Tire specializes in wheels and tires for all trailer sizes and applications. We have dedicated employees to answer any questions you may have regarding tires and wheels of all sizes and applications. Call 402-413-6646 today for pricing and information!

Trailer Tires are now available for online purchase. Click here to put in your tire size and view inventory!