Difference Between Trailer Tires ST205/75D14 and ST205/75R14

Updated 04/14/2024 | Published 03/26/2015

Products Featured in This Question

Karrier ST235/85R16 Radial Trailer Tire - Load Range E

(2098)

$195.26

Loadstar ST205/75D14 Bias Trailer Tire - Load Range C

(3635)

$119.34

Question:

What is the deference between a st205/75D14 and a st205/75R14

asked by: Walt

Expert Reply:

Tire designations ST205/75D14 and ST205/75R14 are both for special trailer tires with a 205mm width, 75-percent aspect ratio and that fit a 14-inch wheel. The difference between them is the tire's type of construction.

The ST205/75D14 tire is a bias ply type with a Load Range D rating. This size/grade tire has a weight capacity of 2,100-lbs at 65 psi. Lower capacity C- and B-rated tires in this size offer weight ratings of 1,760-lbs at 50 psi and 1,430-lbs at 35 psi, respectively. For example, # AM1ST86 is a Load Range C bias ply tire.

The ST205/75R14 tire is radial type that will typically run cooler than a bias ply and this means it will be likely to last longer. Also a radial tire flexes more than a bias ply tire, giving it better ground contact, traction, stability, and tread wear.

I have linked you to a series of articles on trailer tires and wheels that may be of interest to you. We offer tires and wheels alone, and also pre-mounted tire/wheel combinations, that can be seen on the link provided for you.

expert reply by: Adam R

Capt B.

11/11/2021

I have had no good luck with Kenda or Good year trailer tires. Constant blow outs at highway speeds on my tandem axle boat trailer, Tire with less than 400 mile & less than 6 months old. I am considering a light truck tire instead of a trailer tire

Les D.

11/15/2021

If you are having constant tire failures on your trailer, it will have nothing to do with the tire brand. I recommend that you use Special Trailer (ST) tires for a trailer and Light Truck (LT) tires for a light truck. ST tires are designed for trailer needs with stiffer sidewalls. Causes of trailer tire failures include, 1. Tires that become over heated from not having the recommended air pressure, 2. Also over heated from having a tire air leak, 3. Tires that become overheated from being overloaded with weight, 4. Tires that have cracked or damage rubber from age or bad roads, 5. Tires that are damaged from badly installed components like crooked/bent axles that cause excessive wear very quickly. I recommend examining your blown tires to determine the cause of the blowouts.

Capt B.

11/15/2021

@LesD FYI: I have had 4 blowouts this year with Kenda ST205/75 R 14 C & D rated. The tires have had between 350 to 850 miles on them & with a mfg. date of late 2020 or 2021. No idea why they are blowing out. Even the company doesn't know why. Ironically I have 15 year old Kenda tires that are still mounted on the original rims holding air, although they are well tread worn. ???????????????? Capt. Bill Bennett

Capt B.

11/15/2021

@LesD Follow up QuestionsADD COMMENT I have had no good luck with Kenda or Good year trailer tires. Constant blow outs at highway speeds on my tandem axle boat trailer, Tire with less than 400 mile & less than 6 months old. I am considering a light truck tire instead of a trailer tire Is there a higher rated tire than D for 14" rim? Capt. Bill

Ronald

4/14/2024

Thankyou, My trailer will just sit in the parking lot. I do not take it on the road except to service the boat a couple of miles away. Will the ST205/75D14 be ok?