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Old 04-15-2016, 05:23 PM   #1
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Attn Tireman Tire Purchase

Looking for educated opinion about replacing the tires on my Wildwood 27RKSS which has a GVWR of 7720 lbs. Currently I have ST205/75 D15 with a max rating of 1820 lbs.

I would like to replace them with Maxxis M8008 ST225/75 r15 E1 rated for 2540 lbs. The tires measure 27.1 diameter vs 28.3 and width of 8.10 vs 8.90.

There is plenty of room in both directions for the larger tires. Does this sound reasonable giviing my an extra margin of load reserve instead of being less than 10% with the current tires.

Appreciate your opinion
Joe
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Old 04-15-2016, 08:49 PM   #2
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Attn Tireman Tire Purchase

The E rated tire is 2830. You posted the number for a D rating in that size which would be fine for your trailer. Make sure your rim is wide enough.


2010 F250 5.4L 3.73
2011 Flagstaff 831FKBSS
Equal-i-zer 4pt 12K
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Old 04-22-2016, 10:08 AM   #3
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Increasing the "Reserve Load" for your tires is a good step for improving tire longevity.

As long as your clearances are OK and the rim is of the approved dimension (width) and inflation rating I see no reason not to move to a higher Load Range and to run the higher inflation associated with that LR.

Don't forget that it is the air not the tire that supports the load. You will not get more load capacity unless you increase the air pressure (higher Load Range) and/or air volume(larger size tire)
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Old 04-22-2016, 03:44 PM   #4
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Quote:
Originally Posted by Tireman9 View Post
Increasing the "Reserve Load" for your tires is a good step for improving tire longevity.

As long as your clearances are OK and the rim is of the approved dimension (width) and inflation rating I see no reason not to move to a higher Load Range and to run the higher inflation associated with that LR.

Don't forget that it is the air not the tire that supports the load. You will not get more load capacity unless you increase the air pressure (higher Load Range) and/or air volume(larger size tire)
When you step-up and approve a tire size and load range increase for a RV trailer you're sort of stepping in for the trailer's manufacturer who may or may not approve such changes.

Unlike the automotive tire industry there is no approved list to choose acceptable replacements from.

Just wondering how you as a professional would handle a disagreement between you and a RV trailer manufacturer on that subject?

The cat in the bag is what the RV trailer manufacturer has said is appropriate for a vehicle in question. RV trailer manufacturers have attested to that fact by their approval on the trailer's federal certification label. So, is there support from the TRA to recommend RV trailer tire replacements on case by case situations?
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Old 04-22-2016, 07:06 PM   #5
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Originally Posted by Airdale View Post
When you step-up and approve a tire size and load range increase for a RV trailer you're sort of stepping in for the trailer's manufacturer who may or may not approve such changes.

Unlike the automotive tire industry there is no approved list to choose acceptable replacements from.

Just wondering how you as a professional would handle a disagreement between you and a RV trailer manufacturer on that subject?

The cat in the bag is what the RV trailer manufacturer has said is appropriate for a vehicle in question. RV trailer manufacturers have attested to that fact by their approval on the trailer's federal certification label. So, is there support from the TRA to recommend RV trailer tire replacements on case by case situations?
I covered the appropriate guidelines that would apply to any road vehicle.
1. Ensure the tire does not rub against any other component of the vehicle
2. Ensure that the replacement tire has equal or greater load capacity.
3. Ensure the wheel selected is appropriate for the new tire
4. Ensure the speed capability of the new tire is equal to or greater than the tire it replaces.

I think you will find the above guidelines have been published as guidelines for decades. DOT regulations provide minimum requirements for load capability and do not prohibit selecting a better tire than the RV company selected as OE.
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Old 04-22-2016, 11:31 PM   #6
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Quote:
Originally Posted by Tireman9 View Post
I covered the appropriate guidelines that would apply to any road vehicle.
Quote:
Originally Posted by Tireman9 View Post
1. Ensure the tire does not rub against any other component of the vehicle
2. Ensure that the replacement tire has equal or greater load capacity.
3. Ensure the wheel selected is appropriate for the new tire
4. Ensure the speed capability of the new tire is equal to or greater than the tire it replaces.

I think you will find the above guidelines have been published as guidelines for decades. DOT regulations provide minimum requirements for load capability and do not prohibit selecting a better tire than the RV company selected as OE.

In using the information in 1-4, an appropriate replacement tire for RV trailer tires (ST) could be from any design as long as it fit’s the criterions listed above?

How do positional tires such as those earmarked for drive, steer, trailer and all position fit into the mix?

A number of the major LT tire manufacturer’s consider replacing ST tires with LT tires to be a misapplication. Michelin goes as far as to disallow LT replacements of ST tires when the trailer’s owner’s manual disagrees with such replacements.

This statement is found on page 2 of the reference below; Use of MICHELIN tires that is inconsistent with the safety and/or maintenance information provided in your owner’s manual.

http://media.michelinman.com/content/dam/master/Michelin/pdf/Owners_Manual_Post_Promise_Plan.pdf

The RMA recommends replacing ST tires with ST tires. Maxxis only recommends ST replacements for ST tires. Maxxis also builds a fine series of commercial LT tires without a recommendation for trailer service.

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Old 04-23-2016, 12:04 PM   #7
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Have to wonder what you have done when it came time to replace the tires on your car or pickup?

As you know auto companies approve a specific specification tire for application to new vehicles. They do not simply select a size or brand or even design but a specific specification with compound and construction features fine tuned for that exact model vehicle.

For a good many years it was my job to obtain the approval of various tires on specific vehicles.

Have you always used only tires built to the specific spec that was originally approved?

RE my guidelines. Had to start with the basics. You can of course choose to only use the same tires as the ones that came on your RV. I do have to wonder how some are to do that given that there is no dealer network available for many of the no-name tires supplied on many RVs.

I guess we will have to agree to disagree on the question if RV owners have to replace the OE tires with identical tires or not.
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Old 04-23-2016, 02:07 PM   #8
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Originally Posted by Tireman9 View Post
Airdale

Have to wonder what you have done when it came time to replace the tires on your car or pickup?

As you know auto companies approve a specific specification tire for application to new vehicles. They do not simply select a size or brand or even design but a specific specification with compound and construction features fine tuned for that exact model vehicle.

For a good many years it was my job to obtain the approval of various tires on specific vehicles.

Have you always used only tires built to the specific spec that was originally approved?

RE my guidelines. Had to start with the basics. You can of course choose to only use the same tires as the ones that came on your RV. I do have to wonder how some are to do that given that there is no dealer network available for many of the no-name tires supplied on many RVs.

I guess we will have to agree to disagree on the question if RV owners have to replace the OE tires with identical tires or not.
Tire fitment regulations for vehicle manufacturers are not binding on the end users. However, tire industry standards when followed by vehicle owners do not allow much variance.

Standards about size and strength of replacement tires are almost completely standardized and require the vast majority of tire manufacturer retailer's to follow suit with the tire builder's SOPs.

Individual RV trailer owners can install whatever tires they feel safe with and have confidence in. However, I personally feel compelled to point out safety factors overlooked during the selection processes.

Trailer suspensions must also be scrutinized. Will a trailer designed to accommodate 8PR polyester cased tires at maximum loads of 3000# support a completely different design such as a 14PR steel cased 3750# tire?

This is a verbatim quote from the tire safety section of a 2016 RV trailer manufacturer's owner's manual: To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information. If you have any doubt about the correct size to choose, consult with the tire dealer.

Do you have a valid suggestion as to how a tire retailer is to work around that safety statement from the vehicle's manufacturer?

Tire retailers use their own judgment to sidestep that safety warning all the time. In fact they may not even know of it's existence.

Example of a loaded question...........Medical questions form....Q: Do you drink. A: Sometimes when eating out and I am not riving I might have a beer with a pizza ......Translation.... He Drinks?
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