How to Select Trailer Tires with Correct Load Range Rating for Trailer Gross Weight

Question

Question:

Hi, I understand that trailer tires have designated load ranges. What I do fully understand it exactly what that load range means. For example if a trailer tire has a 1300 lb load range capacity, does that mean if you had a trailer with 4 tires two axles the maximum weight of the trailer should not exceed 5200 lbs? 4 x 1300= 5200? In other words, If I had a trailer that has a gross loaded weight of 4000 lbs, each of the 4 tires would have to be load rated for at least 1000 lbs or more? Thank you.

asked by: James L

0

Expert Reply:

Your math is correct in your trailer weight load example. If a fully-loaded tandem axle trailer weighs 4000-lbs then each of the 4 tires will bear 1/4th of that load, or 1000-lbs. In this case a tire rated for 1300-lbs would provide a good safety margin. A tire's rated Load Range means the maximum weight load it can handle (when installed on a suitably-rated wheel) at its full rated PSI pressure.

Trailer tires must always be fully-inflated to their maximum rated pressure as noted on their sidewall. Only when fully-inflated to that maximum psi pressure can a trailer tire deliver its rated weight carrying capacity.

The wheel/tire you referenced, Kenda 4.80-12 Bias Trailer Tire/Wheel # AM30660, combines a steel wheel rated for 1250-lbs with a Load Range C tire that itself is rated for 990-lbs at 90-psi. Since the tire is rated lower than the wheel, the lower rating determines the overall capacity of this item, 990-lbs.

expert reply by: Adam R

0

David M.

9/7/2020

Ok, I just ordered a 5 ton Hudson trailer. (12,000 GVWR; trailer 2k, max load 10k) It comes with four ST 225/75 R15 8-PR tires. D rating = 1220 lbs. per another eTrailer web page. In the context of the above my trailer and load cannot exceed 4880 lbs.?!!? Seriously?? 1220*4=4880 lbs. allowable GVWR because of tire rating. Trailer weighs 2000 lbs. Means the largest weight I can haul is 2880 lbs??!? That can’t be right!

Reply

David M.

9/7/2020

I found a second eTrailer page that has a chart which states the tires on my trailer will support D rating of 2,540 lbs at 65 psi. So that’s makes me feel much better but 2540*4=10,160 still doesn’t support the 12,000 GVWR of the trailer. Is there some kind of demand factor used? I find it hard to believe a company like Hudson Brothers would install underrated tires on their trailers. What’s up?

Reply

Jon G.

9/10/2020

@DavidM Make sure that you are checking the weight rating of the exact tires on your trailer as that can vary some between tire manufacturers. Another thing to keep in mind is that there is the tongue weight of the trailer to look at since this load will be directly placed on the vehicle. Your best bet is to look at the weight rating of your axles and make sure that your tires are rated for at least that much. In all honesty it wouldn't be the first time we've heard of a trailer company saying one rating and then putting equipment on that doesn't quite add up. That's a question you'll have to ask your trailer manufacturer though just to be on the safe side of things.

Reply

Jon G.

9/10/2020

@DavidM Make sure that you are checking the weight rating of the exact tires on your trailer as that can vary some between tire manufacturers. Another thing to keep in mind is that there is the tongue weight of the trailer to look at since this load will be directly placed on the vehicle. Your best bet is to look at the weight rating of your axles and make sure that your tires are rated for at least that much. In all honesty it wouldn't be the first time we've heard of a trailer company saying one rating and then putting equipment on that doesn't quite add up. That's a question you'll have to ask your trailer manufacturer though just to be on the safe side of things.

Reply

David M.

9/10/2020

@JonG No D rated tire I can find adds up, so I'm betting there is some demand calculation they use. I find it difficult to believe Hudson Trailer company puts inadequate tires on their trailers. I'm definitely going to check with them though. I asked the dealer about this and they just said "don't worry, it will be ok". LOL Interestingly, even if using E rated tires I can find none that have a 3000+ rating which is what it would take (4, 3000# rated tires) to support a max trailer GVWR of 12,000#. Thanks for the followup Jon!

Reply

Answer 1

The battery you use for a break away system needs to be able to power the trailer brakes on full for 15 minutes. A 12 volt battery rated for 5 amp hours is normally used, unless you have 3 axles each with brakes, then you would benefit more from a…

view full answer...

Answer 2

In regards to the Hopkins Engager Push-To-Test Trailer Breakaway Kit part #20099, the first issue that you described of the yellow charge light being on even while disconnected from the tow vehicle could either be a short in the circuit board or if…

view full answer...

Answer 3

The difference between an load range C and load range D tire in the same size is the capacity and psi rating. The two tires will still have the same dimensions and fit on the same wheel. The D rated tire has a higher capacity. For a ST175/80D13…

view full answer...

Answer 4

Since the light is staying on even when the trailer is disconnected, this would indicate that the light for the Engager Trailer BreakAway Kit, #20099, is drawing power from the break away battery. The box is water resistant but not water proof.…

view full answer...

Answer 5

You do have a very interesting situation. When it comes to aluminum trailers we always defer to the manufacturer whether it is just a utility trailer or an RV trailer like your toy hauler. Aluminum frames can't always withstand the pressure of a…

view full answer...

Answer 6

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…

view full answer...

Answer 7

The ALKO 4,400 lb axles use the same bearing sizes as the standard 3,500 lb alxes. If you want USA made bearings, I recommend the Bearing Kit #TMK52VR. This kit comes with the Timken brand bearings which are all made here in the USA.

view full answer...

Answer 8

Trailer tires and wheels do not typically come balanced from the factory like what you see with standard passenger vehicle tires. This isn't usually needed for trailer tires and most car shops don't have the needed setup to properly balance…

view full answer...

Answer 9

We have the Dexstar Steel Spoke Trailer Wheel - 15" x 6" Rim - 5 on 5 - White Powder Coat, #AM20528DX, which has a zero offset, which is what I think you are referring to. To determine if you have an offset, you need to measure from where…

view full answer...

Answer 10

Given the same weight load on them, tires of Load Range E will tend to run cooler than tires of Load Range D. The same is true between a LR D tire and a LR C, etc. Since heat is a trailer tire's worst enemy and the root cause for most failures,…

view full answer...

Answer 11

I believe you mean Load Range since the Load Ranger was the unsuccessful brother of the Lone Ranger. For any given tire size there can be different load ranges. The different load ranges have different weight capacities. This has to do with the…

view full answer...

Answer 12

Since both a ST145/R12 size tire, like the Kenda Karrier S-Trail #AM10130, and a 5.30-12 size tire, like the Kenda K353 #AM10068, fit a 12 inch wheel, a ST145/R12 size tire can replace a 5.30-12 size tire. Keep in mind that these tires do have…

view full answer...

How to Select Trailer Tires with Correct Load Range Rating for Trailer Gross Weight

Product Page this Question was Asked From

Featured Help Information

Miscellaneous Media

Continue Researching