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Trailer King Ultra STR ST225/75R15 F/12PLY

Trailer - Radial
Radial

Rims Not Included

easy test score

8.1 Excellent

Availability

In Stock

Per Tire:

$118.28

Estimated Delivery

Shipping

Total

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Category

Trailer - Radial | Radial

TKAS55G

The Trailer King Ultra STR ST225/75R15 F/12PLY Tires is a Trailer - Radial tire. Manufacturer part number: TKAS55G.

Trailer King Ultra STR is an all-steel ST radial tire designed for highway driving of trailers with high load capacities. This trailer tire engineered to deliver long life, great traction, and even wear. Its four wide circumferential grooves serve to evacuate water away from the tire’s footprint, which ultimately reduces the risk of hydroplaning. The cross rib sipes also enhance the tire’s traction in both wet and dry conditions. As the trailers cover long distances at once, it’s important that tire stays cool, which is why the circumferential grooves are deep enough to disperse the heat and keep the tire cool for longer periods of time. Ultra STR’s all-steel construction helps the tire to maintain its shape under heavy loads and extended driving. The stone ejectors embedded in the tread help to minimize the stone retention and protect the casing in the base of the tread groove.

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About the Manufacturer:

Trailer King is a specialized trailer tire brand developed by TBC Corporation, a prominent North American tire supplier established in 1956. Designed specifically for towable applications, Trailer King manufactures ST (Specialty Trailer) radial tires engineered to manage heavy load distribution, lateral sway, and high center-of-gravity demands. TBC Corporation maintains rigorous quality assurance across its global manufacturing network, ensuring every tire meets stringent U.S. Department of Transportation (DOT) and highway safety standards. Trusted by major trailer OEMs, Trailer King delivers certified reliability across utility, cargo, RV, and marine transport sectors.

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Specifications

Specs

Value

Description

Sidewall

Not Available

Describes the sidewall appearance. Examples: BSW= Black Side Wall, WSW = White Side Wall, OWL = Outlined White Letters.

Load Index

121

The load index (LI) is a 2- or 3-digit number that correlates to the maximum amount of weight the tire can carry. For example, a tire with a load index of 87 indicates that the tire can carry a maximum load of 1,201 lbs. In this particularly example, 4 tires (each with a load index of 87) can carry a maximum of 4,804 lbs. Refer to your vehicle owner's manual for the recommended minimum load index.

Speed Rating

Speed rating (SR) indicates the maximum speed the tire can achieve. Higher speed ratings are typically associated with better handling capabilities. Refer to your vehicle owner's manual for the recommended minimum speed rating.

Load Range/Ply Rating

F/12PLY

Ply rating, more commonly referred to as load range, represents the strength and durability of the tire. Higher ratings may indicate your tires can handle heavier loads.

UTQG

Not Available

To help consumers evaluate their tires, the U.S. National Highway Traffic Safety Administration (NHTSA) created the Uniform Tire Quality Grading System (UTQG). The UTQG rates tires are rated on their tread-wear, traction performance, and temperature resistance. The grade for each of these can be found on the sidewall of your tire (except for winter tires and certain light truck tires).

Max Single Load(lbs)

3195

The maximum load this tire will support. Remember to multiply this number by the number of tires installed on your vehicle to get the maximum carrying capacity. This number is directly related to the Load Index.

Max Single Air Pressure(PSI)

The maximum air pressure this tire will support. This does not represent the amount of air pressure your tires should have at all times. Consult with your owner's manual to determine the best air pressure you should use for your vehicle.

Tread Depth

13.0

The amount of tread on the tire. Once the tire is worn to 2/32nds, it is considered fully used and should be replaced at that time. Most tires will have tire indicators in the grooves of the tire to help you determine when the tires are worn down to 2/32nds.

Tread Design

Nondirectional

The pattern of the grooves, lugs, voids, and sipes on a tire's surface. This design affects the tire's traction, handling, and noise characteristics. Common types include symmetrical (uniform pattern across the tire), asymmetrical (different patterns on the inside and outside for varied road conditions), and directional (designed to rotate in one direction for improved wet traction and hydroplaning resistance).

Rim Width Range

Not Available

The approved wheel rim width range this tire will support.

Measured Rim Width

Not Available

The recommended wheel width as recommended by the tire manufacturer to get the best wear us performance for this tire.

Section Width

8.8

The measurement from sidewall to sidewall.

Tread Width

Not Available

The measurement from one side of the tread to the other side of the tread.

Overall Diameter

Not Available

The height of the tire when fully inflated.

Manufacturer Part Number

TKAS55G

Manufacturer part number (sku)

Size Details

Size	Load Index/ Speed index	UTQG	Load Range/Ply Rating	Overall Diameter	Section Width	Rim Width Min	Rim Width Max	Rim Width Meas	Tread Depth (in)	Max Single Air Pressure (PSI)	Max Single Load (lbs)	Max Dual Air Pressure (PSI)	Max Dual Load (lbs)	MFG #
ST225/75R15	121N	-	F/12PLY	-	8.8	-	-	-	13.0	95	3195	-	-	TKAS55G
ST235/80R16	129/125L	-	G/14PLY	30.8	9.3	-	-	6.5	12.0	110	4080	110	3640	TKAS25G
ST235/85R16	132/127L	-	G/14PLY	31.7	9.3	-	-	6.5	12.0	110	4400	110	3860	TKAS18G