Can a Load Range C Tire Be Replaced with a Load Range D Tire

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Question:

I recently replaced my C rated tiresST205/75R14/Cwith ST205/75R14/D tires which raised the max cold PSI from 50 psi to 65 psi. I have heard several different recommendations on which tire psi to use. Some say use the max cold pressure of 65 psi all the time, others say use less or equal to the original max tire pressure of 50 psi, and others say use a psi based on the Goodyear load/inflation chart which appears to be based on the max rating of each axle. If my max trailer rating is 1760 per tire for the Casita and the recommended original tire pressure was 50 psi, should I use 50 psi for the new tires regardless of the cold psi rating of 65 or can I run the tires at the 65 psi if the trailer loaded weight is at or below the max of 1760 per tire? Would using less than the 65 psi for the D tire cause any tire damage? Thanks

asked by: Jack

1

Helpful Expert Reply:

Yes, you can replace your load range C tires with load range D tires without issue. It will only become any issue when you go down load ranges, not up. The tires will have the same overall diameter as long as they are the same size regardless of their load range. If you are looking for a recommendation on a 205/75-14 tire I recommend the Karrier ST205/75R14 Radial Trailer Tire part # AM10235.

This tire has a radial construction which is better for long highway hauls, a load range D rating which is 2,200 lbs per tire, and a speed rating M which is suitable for use up to 81 MPH. Kenda is our best tire manufacturer and they come with a two year warranty. I have attached a review video for you.

expert reply by: Conner L

1

Jack

6/25/2018

I recently replaced my C rated tiresST205/75R14/Cwith ST205/75R14/D tires which raised the max cold PSI from 50 psi to 65 psi. I have heard several different recommendations on which tire psi to use. Some say use the max cold pressure of 65 psi all the time, others say use less or equal to the original max tire pressure of 50 psi, and others say use a psi based on the Goodyear load/inflation chart which appears to be based on the max rating of each axle. If my max trailer rating is 1760 per tire for the Casita and the recommended original tire pressure was 50 psi, should I use 50 psi for the new tires regardless of the cold psi rating of 65 or can I run the tires at the 65 psi if the trailer loaded weight is at or below the max of 1760 per tire? Would using less than the 65 psi for the D tire cause any tire damage? Thanks

Conner L.

6/25/2018

We always recommend you fill trailer tires to the max psi listed on the sidewall while cold. This will ensure that you are able to benefit from the full load range of the tire. If you filled a tire to 50 psi when the sidewall called for 65 psi then you would not have as a high of a weight capacity. The recommended cold fill psi will also take into consideration the rise in psi that occurs as the tire begins to warm. Filling the tires to 50 psi when they are rated at 65 psi could also cause them to wear more on the outside edges which would mean you would need to replace them much sooner then when filled to the manufacturer's recommended psi. They may also not be covered under warranty if not filled to their max psi.

Bill W.

8/24/2025

Have 4 tires on a boat trailer, ST205/75R14 Load C. I routinely blow ATLEAST 1 tire a season. Want to go up to Load D but can’t afford to do all 4 right now. I’m told I can mix Load C and D’s together as long as they’re on the SAME AXLE. That way I only need to buy 2 Load D’s until I can get the other 2. True?

Nick S.

8/25/2025

@BillW Ideally yes you want to replace all 4, however in your situation 2 on one axle will be fine for the time being. If you were to use 2 different load range tires for a longer period of time it can cause uneven ware on the tires and potential blowouts. Specifically on the lower rated tire. Since you are wanting to go with all 4 anyway, a temporary fitment of the 2 will be fine to do.

Bill W.

8/25/2025

Hey Nick; Thanks so much for the info. You were the deciding vote, although my checking account won’t like it. I’m hearing from everyone that its best to just bite the bullet and buy 4 Load D tires. Ordered 4!Load D tires this morning. Appreciate your time!

Nick S.

8/25/2025

@BillW I just replaced mine on my own trailer just last week. Still biting the bullet on that one so I understand that! I think in the long run you are going to appreciate doing all 4 at once. You'll have to let me know how they are when you get them.

Answer 1

Hey Greg. Since your 2019 Pace Arrow LXE 38K is a class A motorhome with a diesel engine, TireMinder says you need to mount the repeater, included with item #TM98FR, as close to the rear axle as possible. Their website specifically states to avoid…

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Answer 2

The load range has to do with the horizontal and sidewall strength of a trailer tire. The C range tires are 6 ply and the D range tires are 8 ply. Because you are operating at half of the spring capacity of your trailer, bumping to a higher load…

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Answer 3

Trailer tires have a lifespan of 5-6 years or 10,000-12,000 miles - whichever comes first. If you were going on a shorter trip I would say you can stretch them out a little more, but since you're almost doubling up their mileage and they are that…

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Answer 4

Anyone with a jack that can get the wheels off the ground can install tires/wheels on your 5th wheel. If you are looking for a company that can install the tires on your wheels, you can use any tire store that does automotive tires. The way the…

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Answer 5

The TireMinder i10 TPMS for RVs and Trailers w/ Signal Booster - 6 Flow Through Tire Sensors #TM98FR should not be used with rubber stems. The TireMinder i10 TPMS for RVs and Trailers w/ Signal Booster - 6 Tire Sensors Item #TM29FR can used with…

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Answer 6

You are dead on in you analysis of the two Tireminder i10 TPMS kits. The #TM98FR uses screw on sensors that need to be removed to air up the tires, where the #TM29FR uses screw on sensors that are flow through so they do not need to be removed when…

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Answer 7

The D in 205/75D15 represents that the tire has a bias ply construction whereas the R in 205/75R15 represents that the tire has a radial ply construction. The difference between a bias and radial ply is in regard to the directions of the cords. In…

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Answer 8

Excellent question. There is no disadvantage to using a special trailer tire with a higher weight Load Range Rating than is required by your trailer's weight. Doing so simply means that those higher-rated tires will tend to run cooler, since they…

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Answer 9

Not a dumb question at all Andrew, since we don't really touch on this in our description. The Loadstar ST205/75D15 Bias Trailer Tire w/ 15" Silver Mod Wheel #AM32253DX does come balanced in the manner that all trailer tires are balanced. We…

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Answer 10

Hey Matt, it looks like the closest we can get to what you're looking for is the Loadstar ST205/75D15 Bias Trailer Tire w/ 15" Silver Mod Wheel #AM32253DX which is a tire and wheel combo that has a 5 on 5 bolt pattern, and has a 3.19"…

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Answer 11

To know exactly what key will fit your enclosed trailer's access door lock we'll need to know the brand and the key code. For example, since you were looking at a Bauer door lock, if your key code was 357 then you could use the Replacement…

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Answer 12

Hey Eric, It's pretty normal to go up a load range if you're feeling like the trailer is being overloaded since tire wear and capacity go hand in hand. It's ok to have some extra capacity when it comes to the wheels, however, going with…

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Can a Load Range C Tire Be Replaced with a Load Range D Tire

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