Tires: Changing From D To E

bpounds wrote:

JIMNLIN wrote:


You can farther your knowledge about the subject about proper tire pressures/ply shear/etc for tires on a trailer from Tireman9 rvtiresafety.com

Great source of information for trailer owners.

You and he make the same mistake, and only think in terms of load capacity. Think about the more robust construction of an LRE. Think about road hazards that we are all going to get, no matter how carefully try to avoid them.

The LT lovers like to note how much heavier and stiffer an LT tire is compared to an ST, even though the load capacity may be lower. The advantage of a heavier tire, with more belts, is obvious. The same is true of an LRE ST tire. I just don't get how anyone could argue that an extra radial belt in a tire in of no benefit.

Would you rather drive over a sharp rock with an LRD or an LRE, assuming both trailers weigh the same? Seems like a no-brainer. There is more to tire construction than just load rating.

Our points had nothing to do with load capacity.

Been there and done that and I'll take a D at max pressure over a derated E tire at 65 psi anytime when used in a trailer position.
As the tire engineer say the E tire at only 65 psi provides no benefit over the 65 psi rated D tire.

You mention more belts. The E tire has the same number of carcass and tread belts as the D tire. The carcass plies (sidewall) in a E tire are heavier/thicker than the D tire. The ST has the same amout of belts as the LT.
Beside ply shear Tireman9 tells us about is heat build up in a tire with less than max pressures.
When I was young and dumb and didn't listen to my truck tire dealer who knew about proper tire pressure for tires on a trailer. I also thought I could run those big heavy tires on my equipment trailers at those low pressures. After several tread delams caused by using a minimum pressure from a tire chart I learned a expensive lesson about proper tire pressures. And with five trailers with twenty eight tires on the ground it was a expensive lesson.

You can derate a good E tire if you want but its been my experience it didn't work the best in the long term.

danrclem wrote:
I finally got a chance to take a wheel off and it's a T15x6JJ 6 lug. The tires are 225/75 15. I couldn't find a rating for pressure on the rim but every rim I found in this size had a rating for 80 psi so I'm going to go with the E rated tires. It'll make me feel better and they only cost $26 more for a set of four.

Thanks for all of the good advice.
Danny

If it were me, because I've already done it on my 2 RVs is to upgrade your wheels and tires from 15" to 16" and go with good ST E rated tires, I run Maaxis and haven't had any issues but by upgrading, it gave me a little more cushion as far as my load rating of my tires. If you plan on staying at 65mph or slower then the STs are fine, if you think you have to be a speed demon as some then you better get the LTs but again you have to watch the weight rating.

bpounds wrote:

laknox wrote:

bpounds wrote:
Also, to clarify, the PO did not specify, but with a 10k trailer, I was assuming he has 15" tires. There are no good LT tire alternatives in a 15" tire.

Different ballgame in a 16" tire, and LT is the way to go on those. For a 10k trailer, it is overkill to change wheels to 16", even if they happen to fit the wheel wells, and they often won't.

And yet Jayco and KZ, that I know of, are offering 16"/E tire options on the Eagle HT and Durango 1500 lines, with GVWs of 9950 and 10,500, respectively.

Lyle

Might be driven by customer requests. Good thing to do on a new trailer, and I would consider that.

When I said overkill, I meant discarding 15" wheels and going out and buying 16" wheels so you could upgrade to an LT tire. Not a bad thing to do, but for 10k not really necessary IMO. Overkill? It was to me, but that's not necessarily a bad thing. Clearance issues and possibly rougher ride aside. Let's just say I got where I wanted to be without doing that. As you did also, and I believe you weigh in a bit heavier than mine.

My Komfort has a GVW of 11,320 per the sticker, but was placarded for D's. Yes, they work...but why not have the option of E's for more safety. I'm just glad my OEM aluminum wheels were rated for 80 psi, so I didn't have to change them, too. If/when I get a new FW, it will have 16" wheels on it...period. I don't ever see myself going to something big enough to need 17.5's. :-)

Lyle

laknox wrote:

bpounds wrote:
Also, to clarify, the PO did not specify, but with a 10k trailer, I was assuming he has 15" tires. There are no good LT tire alternatives in a 15" tire.

Different ballgame in a 16" tire, and LT is the way to go on those. For a 10k trailer, it is overkill to change wheels to 16", even if they happen to fit the wheel wells, and they often won't.

And yet Jayco and KZ, that I know of, are offering 16"/E tire options on the Eagle HT and Durango 1500 lines, with GVWs of 9950 and 10,500, respectively.

Lyle

Might be driven by customer requests. Good thing to do on a new trailer, and I would consider that.

When I said overkill, I meant discarding 15" wheels and going out and buying 16" wheels so you could upgrade to an LT tire. Not a bad thing to do, but for 10k not really necessary IMO. Overkill? It was to me, but that's not necessarily a bad thing. Clearance issues and possibly rougher ride aside. Let's just say I got where I wanted to be without doing that. As you did also, and I believe you weigh in a bit heavier than mine.

bpounds wrote:
Also, to clarify, the PO did not specify, but with a 10k trailer, I was assuming he has 15" tires. There are no good LT tire alternatives in a 15" tire.

Different ballgame in a 16" tire, and LT is the way to go on those. For a 10k trailer, it is overkill to change wheels to 16", even if they happen to fit the wheel wells, and they often won't.

And yet Jayco and KZ, that I know of, are offering 16"/E tire options on the Eagle HT and Durango 1500 lines, with GVWs of 9950 and 10,500, respectively.

Lyle

The load range and max air pressure cross over between D and E. Max air pressure is just that and nothing else. Just do not go over the max. The amount of air pressure you need is determined by the weight of the load. If you need max you need a G tire.

There is a lot of confusion on tires. That is why there are so many blow outs.

danrclem wrote:
I couldn't find a rating for pressure on the rim but every rim I found in this size had a rating for 80 psi so I'm going to go with the E rated tires.

Often just a weight rating that will match the E tire.

JIMNLIN wrote:


You can farther your knowledge about the subject about proper tire pressures/ply shear/etc for tires on a trailer from Tireman9 rvtiresafety.com

Great source of information for trailer owners.

You and he make the same mistake, and only think in terms of load capacity. Think about the more robust construction of an LRE. Think about road hazards that we are all going to get, no matter how carefully try to avoid them.

The LT lovers like to note how much heavier and stiffer an LT tire is compared to an ST, even though the load capacity may be lower. The advantage of a heavier tire, with more belts, is obvious. The same is true of an LRE ST tire. I just don't get how anyone could argue that an extra radial belt in a tire in of no benefit.

Would you rather drive over a sharp rock with an LRD or an LRE, assuming both trailers weigh the same? Seems like a no-brainer. There is more to tire construction than just load rating.

I don't accept that. It is only true if you are looking for the added load capacity.

I'm not surprised. Many folks don't understand why we use max pressures for tires on our trailers unlike tires on the tow truck.

This tire expert doesn't agree with you either.

Tireman9
rvtiresafety.com


The question of load capacity and Load Range gets asked a lot, so it seems to be a bit of a stumbling block for a number of RV owners. Here is an example:
"I need to replace the ST235/75R15 tires on my trailer. Currently have load range C tires which is sufficient for the maximum trailer weight when inflated to 50psi but allows almost no safety margin. I want to change to either load range D or E tires. My rims are only rated for 65 psi so if I went to the load range E tires I would only be able to inflate them to 65 psi. My question is this. Is there any advantage to a load range E tire used at 65 psi vs a load range D tire at 65 psi?"

Now just because he is asking about a 15" trailer application and considering a change from LR-C to LR-D it does not mean the general answer does not apply to others, even if they are considering a change from LR-G to LR-H on a Goodyear 295/75R22.5 Class-A tire.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

The answer to the question is;
He will gain a safety margin if he increases his inflation to 65psi with LR-D but if he stays at 65psi there is nothing further gained by going to LR-E as there is no difference in the capacity at 65psi.
The same thing would apply to the 22.5 example. When we look at the Goodyear tables we see that at 110psi both the LR-G and the LR-H are rated for 6,175# single or in dual application at 100psi they both are rated as 5,675#.

Special note: It is important that you look at the table on the web site of the manufacturer of your tires as not all companies give the exact same capacity number at every inflation level, even for the same size.

You can farther your knowledge about the subject about proper tire pressures/ply shear/etc for tires on a trailer from Tireman9 rvtiresafety.com

Great source of information for trailer owners.

I finally got a chance to take a wheel off and it's a T15x6JJ 6 lug. The tires are 225/75 15. I couldn't find a rating for pressure on the rim but every rim I found in this size had a rating for 80 psi so I'm going to go with the E rated tires. It'll make me feel better and they only cost $26 more for a set of four.

Thanks for all of the good advice.
Danny