RE: Dilema - Four New Tires for TT

KEN9XL · 05-24-2020, 05:40 PM

I purchase four new tires for my Travel Trailer last weekend.
All four tires were the same size & price on bill (ST225 75R 15)

This weekend, I went to check the air pressure in the tires and found they were not the same tires. Two tires were rated for 2540lbs (D8 113L) and the other two tires were rated for 2860LBS (E10 117M).

Wish I realized this mistake day of installation.

Here is the tire breakdown as stated on the sidewalls -
(load range, load index, & speed index) - DOT 0720, 3rd week Feb 2020
D8 = 8 ply / 65psi max with 113 = 2540lbs max and L = 75MPH max
E10 = 10 ply / 80psi max with 117 = 2860lbs max and M = 81MPH max

Question - If I fill the E10 / 117M tires to 65psi so I match the other tires, what does that do to the max weight per tire?
I know the max weight will go down, but any idea to where?
What does that do to the sidewalls or life of the tire?
Biggest question is safety. Is this possible, running at lower PSI?

I cannot find any conversion chart for this, but I am sure the lower air pressure is not a good thing for the higher rated tires.

Any help or clarification would be appreciated.

Thanks!

**Flybob** · 05-24-2020, 05:47 PM

Sounds like you have different load range tires. Does the bill specify a load range. If so you may want to call the dealer. When I replaced mine I noticed they installed the incorrect load range. I caught it and had them remove and install the correct ones.

Mike134 · 05-24-2020, 06:10 PM

Don't have an answer for you but I'm curious

Where these tires installed by the "pros" from an RV shop or the "pros" of a tire shop?

KEN9XL · 05-24-2020, 06:43 PM

Quote:

Originally Posted by Flybob

Sounds like you have different load range tires. Does the bill specify a load range. If so you may want to call the dealer. When I replaced mine I noticed they installed the incorrect load range. I caught it and had them remove and install the correct ones.

Nope! Only thing it states on bill is the size of the tires as ST225-75R-15, nothing else. Definitely different load range tires, that is why I questioned it.
Guess I call the tire place that installed them come Tuesday and get it the tires corrected.
Thank-you!

KEN9XL · 05-24-2020, 06:47 PM

Quote:

Originally Posted by Mike134

Don't have an answer for you but I'm curious

Where these tires installed by the "pros" from an RV shop or the "pros" of a tire shop?

Installation by a Tire Shop, not RV Shop. Surprising Huh!
You would think they would be on the ball. Must have been in a rush and not paying attention. Wasn't like I was there at end of day. It was early afternoon, mid week. I'll let you know what happens once I call or visit come Tuesday.

EdJunior · 05-24-2020, 06:49 PM

We need WMTIRE here. He should be able to help you out.

aceinspp · 05-24-2020, 06:54 PM

Quote:

Originally Posted by EdJunior

We need WMTIRE here. He should be able to help you out.

X 2 Later RJD

**dcheatwood** · 05-24-2020, 06:55 PM

Well, the load range E, 10 ply tires cost more. I wonder if they charged you load range D or E prices? And what tire your RV calls for. You could be under-tired if it calls for 4 load range E tires. I'd take it back and get it corrected.

llr · 05-24-2020, 07:10 PM

What does the sticker on the camper call for? If it is the 65PSI LRD (or lower) then you are ok and run all 4 at 65PSI max. If it calls for higher you need at least 2 replaced before you use it.

The 2nd question is what did you request and pay for, again if it was the 65PSI LRD then you got the better deal and no issue that I see. They may have only had 2 LRD and bumped the other 2 up to LRD to avoid ordering or delay.

HangDiver · 05-24-2020, 07:21 PM

It might be that somebody in the tire shop pulled the wrong tires off the rack, maybe.

KEN9XL · 05-24-2020, 07:35 PM

Quote:

Originally Posted by dcheatwood

Well, the load range E, 10 ply tires cost more. I wonder if they charged you load range D or E prices? And what tire your RV calls for. You could be under-tired if it calls for 4 load range E tires. I'd take it back and get it corrected.

That is my plan, Tuesday go back to shop and hopefully correct.
Original tires that came with TT were load range D and max load index 2540lbs.
So originals were ST225/75R15 D 113L 8 ply, not load range E.
Unknown which way they charged me. All 4 for E range or all 4 for D range.
I will certainly find out after the holiday.

rsdata · 05-24-2020, 07:44 PM

you may be able to google the tire brand/size and get an olnline cost for comparison...
etrailer dot com has many tire brands and sizes that you may find for price comparisons

KEN9XL · 05-24-2020, 08:02 PM

Quote:

Originally Posted by llr

What does the sticker on the camper call for? If it is the 65PSI LRD (or lower) then you are ok and run all 4 at 65PSI max. If it calls for higher you need at least 2 replaced before you use it.

The 2nd question is what did you request and pay for, again if it was the 65PSI LRD then you got the better deal and no issue that I see. They may have only had 2 LRD and bumped the other 2 up to LRD to avoid ordering or delay.

Unknown on the LRD portion. Here is a copy of my TT sticker relating to tires.

I am guessing I paid for 65psi (D range) because that is what I requested.
Specified when ordered tires ST225/75R15 D 113L.
As for actual bill they wrote up, which I saw after I made payment, it only shows tire size nothing else (ex: ST225/75R15).
I would hope they would match old tire size to new.
Could they have made a mistake, yes, I will give them that much.

rsdata · 05-24-2020, 08:25 PM

KEN9XL...

to answer your question... I do not believe this is a safety issue with all 4 tires filled to the pressure required on the D-rated tires. I run D-rated tires on my C-rated tire trailer at 55# instead of 65# all the time.

If you are out and about and away from the tire store you bought at, I would think a phone call to them is in order. I would not put my vacation or travels on hold over it, unless they demand you bring it back ASAP to correct their mistake... which I would doubt they would ask you to do.

Since the trailer requires D load range and 2 of the sizes are correct, I suspect they threw on 2 E-rated tires because they did not have 4 D range in stock. This would not be an issue, except for the fact that they did not level with you at the time of sale to tell you what they did.

They may also have made a mistake with the 2 tires, but I bet it was more of a mistake of having enough of what you needed in stock, and trying to keep you happy to be able to drive off with 4 new tires.

I would ask them what happened, how this can happen and that you are not that happy with the mis-matched tires and see what the response is.

On the other hand if the pricing is for 4 D range tires they probably lost $10 times 2 tires to make you a happy customer, and you could leave it at that without an issue as all 4 tires are adequate for the job of supporting your trailer. No change in pressure for the E rated then you would put in D rated.

Mike134 · 05-24-2020, 08:29 PM

When I buy 4 tires for my car, truck or trailer I kinda like having all 4 the same.

KEN9XL · 05-25-2020, 11:40 AM

Agree on all four tires the same.
My issue is D rated tires fill at 65 psi vs E rated tires at 80 psi.
If I fill E rated tires to 65 psi, what will that do to tire wear or sidewalls?
I am afraid of more rapid wear or sidewall breakdown.

If I was charged for D rated and saved money by getting E's, then Yes, money in my pocket. Must see if honest mistake or not enough my brand in stock.

I will certainly go without Travel Trailer in morning (Tuesday) with receipt in hand and ask questions about tire purchase.

dalford · 05-25-2020, 12:19 PM

Quote:

Originally Posted by KEN9XL

Agree on all four tires the same.
My issue is D rated tires fill at 65 psi vs E rated tires at 80 psi.
If I fill E rated tires to 65 psi, what will that do to tire wear or sidewalls?
I am afraid of more rapid wear or sidewall breakdown.

If I was charged for D rated and saved money by getting E's, then Yes, money in my pocket. Must see if honest mistake or not enough my brand in stock.

I will certainly go without Travel Trailer in morning (Tuesday) with receipt in hand and ask questions about tire purchase.

Should be no problem as long as the E rated tire will hold your load. My Goodyear Endurance tire are rated at 3000lbs at 65psi.

I run my F350 front tires at 65psi when not pulling 5th wheel.

The sidewalls would only be damaged if the tires were under inflated for the load.

dalford · 05-25-2020, 12:25 PM

Who is the mfgr of the E rated tires? Should be able to find a load range chart. Folks in motor homes adjust pressure to make ride smoother. You don’t have to run a tire at max pressure. You only need enough pressure plus some margin for your load.

Tundra 2014 · 05-25-2020, 12:44 PM

I would take it back and talk to them at tire shop. I always go up on load range when I get new tires. I have found the OE tires are usually the bare minimum load rating allowed. On my current trailer, original tires were too low rated, even taking the tongue weight off. I would want all 4 to match. Even if you still run them @ 65 PSI you will have additional load and sidewall protection. Even if you have to pay slightly more for the 2 additional higher rated tires. Tire shops error.

**Flybob** · 05-25-2020, 12:53 PM

Certainly not a tire expert and may be a very subtle difference, but I would guess the different tires would wear/run slightly different. You may not see or feel a difference and even a little wear difference should not matter as TT usually never "wear out". I would still call and ask. If you wanted "E" range then a call is needed.

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