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Old 01-30-2021, 05:55 PM   #1
RandyCougar
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Upsizing Tires

I have a 2003 Keystone Cougar that has 205/75/15 tires. They are 6 ply rated I think. As I get ready to travel this Spring, I want to have the best possible tires on it. I went to Les Schwab and asked if I could put 225's and get a 10 ply tires. They said I could not.

Interested in what others have found out.
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Old 01-30-2021, 06:04 PM   #2
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Quote:
Originally Posted by RandyCougar View Post
I have a 2003 Keystone Cougar that has 205/75/15 tires. They are 6 ply rated I think. As I get ready to travel this Spring, I want to have the best possible tires on it. I went to Les Schwab and asked if I could put 225's and get a 10 ply tires. They said I could not.

Interested in what others have found out.
There are some real tire experts on here. Im sure you will get an answer.
I believe the correct answer is you can go up in load range D to E. Etc and keep all of your other sizes the same . Although some will say it’s ok to go up a size as long as you have the space to do so. Keep in mind your wheels need to be rated for any additional psi requirements.. I’m thinking of the going up a size myself because that’s all that is available to keep my tire load capacity above or equal to what I currently have in Goodyear endurance
Again others on here have more experience
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Old 01-30-2021, 06:11 PM   #3
RandyCougar
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I will also be getting new rims at the time I get tires. I hope to get a higher rated tire and it seems that I will need to get a bigger size to be able to do that.
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Old 01-30-2021, 06:15 PM   #4
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Originally Posted by RandyCougar View Post
I will also be getting new rims at the time I get tires. I hope to get a higher rated tire and it seems that I will need to get a bigger size to be able to do that.
I think if you go into a tire place ( reputable) and tell them the stock size tire and make of any vehicle , then they are required to say it isn’t allowed for them to change sizes.
If you were to walk into the same place with just a wheel and say what can I put on this ? Then they would probably give you a list of available tires
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Old 01-30-2021, 06:17 PM   #5
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Quote:
Originally Posted by RandyCougar View Post
I have a 2003 Keystone Cougar that has 205/75/15 tires. They are 6 ply rated I think. As I get ready to travel this Spring, I want to have the best possible tires on it. I went to Les Schwab and asked if I could put 225's and get a 10 ply tires. They said I could not.

Interested in what others have found out.
Members on here seem to rate sailuns,then Carlisle and finally if you want to spend the money ..Goodyear endurance . You may find your size and be able to go up in load range in one of the three
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Old 01-30-2021, 06:45 PM   #6
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Your 205/75R14 LRC (6 ply) tires are rated at 1760 pounds at 50 PSI.

You can buy 205/75R14 LRD (8 ply) tires that are "considered the same size tire" and have no restrictions on installation on your trailer at any tire dealership. They are rated at 2040 pounds @ 65PSI.

Your current tires have a total load rating of 1760x4= 7040 pounds
installing LRD tires in the same size would provide 2040x4=8160.
That would give you an increase of 1120 pounds while keeping your tire size the same as OEM tires.

Carlisle Radial Trail HD in that size is available at WalMart for $66 (LRD) a tire.

The LRC tires are listed for $58 per tire.

https://www.walmart.com/ip/Carlisle-...-LRD/776685932

Typically, Discount Tire will match WalMart's price, sometimes they will offer a discount to beat the competitor's price.

You will need to verify that your current wheels are rated for the 2040 load, but if they are 5 lug wheels, I'd suspect they are OK. Still, verify for sure.
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Old 01-30-2021, 09:08 PM   #7
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The following quote is from the Keystone owner's manual. The quote is there because its a NHTSA mandate as its an industry wide standard.

For a tire retailer to change designated sizes that are not authorized by the vehicle manufacturer, they would have to take full responsibility for that action.


"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."

As JRTJH has said, going up in a tire's load capacity does not constitute a size change, just added load capacity with increased inflation pressures. But, valve stems and wheels must have the capacity to support the increased inflation pressures - LRC 50 PSI to LRD 65 PSI
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Old 01-31-2021, 11:40 AM   #8
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Upgrading tire size, here’s my take…


RV tires, wheels, brakes and suspensions are the bare minimum that the manufacturer can legally install to accommodate the load, in most cases. The sizing specified for that particular coach should, in my mind, be considered a minimum rating. Some of the higher end manufacturers will provide higher quality components but that is not the standard in this industry. Citing a section of a manual prepared by the legal team of a manufacturer that states that replacement tires and wheels should be the same as OEM is narrow minded and not in the best interest of performance or reliability, rather it is in some other interest that I don’t understand.Your tow vehicle has the same verbiage in the owner’s manual as well but there is an entire worldwide industry devoted to upgrading wheels and tires on just about every piece of equipment that rolls. The notion that end user upgrades are not allowable is ludicrous.


In my opinion, the biggest wheel width and diameter that will bolt on your coach safely, providing it meets the minimum weight requirement and matches the “tire” manufacturers recommendations, is a performance upgrade. There are of course, many considerations in that equation. Ride height and clearance are just two of the major factors. Larger tires on the same width wheel is a spec that, while I’m not generally a fan of due to increased sidewall flex, if it provides a load bearing margin of safety, I could see that as an upgrade. BTW, I made that same upgrade many years ago on a 26’ Aljo and was pleased with the margin of safety it provided.


My coach was provided with 15x6’’ upgraded aluminum wheels with 225/75 15 D rated Trailer King tires, the coach GVW is 10,300 lbs. Sure it meets the minimum standard but the term inadequate comes to my mind. I know that trailer wheels and tires do not have the same demands as steer and drive wheels on a tow vehicle but come on now, my 86’ 2500 lb Jetta had 6’’ wide wheels…stock!


My coach now has 17x9’’ wheels with 245/75 17 e rated tires that spec at around 600 lbs greater capacity, each. Some of the “by the book guys” may say that trailer tires have greater side loading built in to their carcass, but my 17’’ e rated LT tire has a much stiffer sidewall than the 15’’ ST tire that was spec’d for the coach.
Now about valve stems…A quick check on the Tire Rack website produced some pretty good info on valve stems. It seems that all rubber valve stems used today have a minimum rating of 65 psi, so I don’t see it as a negative if your choice is to up your tire to a D range tire, you will buy new stems on the new tire mount up I presume.


Wheel rating…Can’t imagine that any steel or aluminum wheel would not meet a 65 psi rating but that number should be stamped on the inside of the wheel. As you did not indicate that you intend to carry more weight and that you are interested in the safety factor that a higher rated tire will provide, a load range D tire in a 225/75 15 ST tire is available and also spec’d for a 6-7’’ wide wheel, I see them on the Tire Rack website with a rating of 2540 lb. This was not a recommendation for that specific tire, just an example of availability.


My opinion is that I would make that change without hesitation, but would consider a rim upgrade to a wider width, if it would fit.


Cheers
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Old 01-31-2021, 01:06 PM   #9
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I failed to mention that I will be getting new wheels as well. The white steel wheels I have are rusty and in 2 cases, rusty around the stems. I am looking at some nice 5-spoke wheels that have a higher load rating than even the all steel wheels.
So, I have a blank slate and want the highest rated tires reasonably available.

I do not intend to carry a lot of extra weight, just normal loads, but would like to avoid blow-outs as much as is possible. The tires on the trailer are the originals, so they are way past due to be replaced. I knew that when I got it and that is why I have stayed very local. I have had one flat, but it was not a blow-out while at speed, just while sitting.
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Old 01-31-2021, 01:57 PM   #10
lunge motorsport
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Randy...
I recall a search I made for wider wheels in 15'' white steel spoke style. I found that 15x7'' sizing were available in zero offset, similar to most trailer wheels. This will add 1/2'' to the inside and outside dimension of the wheel at the bead for clearance considerations, much like a 20 mm wider tire will add a little over 3/8'' in and out at the tread. 19 mm is very close to 3/4'' and you are considering a 20 mm increase.
I'm on board with this upgrade 100%


Cheers
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Old 01-31-2021, 04:51 PM   #11
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Sometimes it's a little unpopular to provide information from the pages of the Keystone Owner's Manual. All vehicle owner manuals have mandated information that is mandatory and must be provided in the owner's manual. Tire size is one of them. It's an industry wide standard. Here it is from another source, Michelin.

For maximum safety, Michelin recommends to only replace your tires with the same size recommended by the vehicle manufacturer.

Hopefully Some advice;

Never choose a tire that is smaller in size or has less load-carrying capacity than the tire that came with the vehicle.

Tires should always be replaced with the same size designation ó or approved options ó as recommended by the vehicle manufacturer.
The correct tire size designated for your vehicle should always be verified with the information in your vehicle ownerís manual.

Michelin wording is a little different, probably because hey don't like to be reminded that there are some things they have no control over.

Note: I live 10 miles from Michelin of North America. I have a lot of friends associated with Michelin and know first hand they really don't like to play second fiddle.
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Old 05-11-2021, 05:51 PM   #12
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Well, if you'd need something bigger, would these 30 inches rims and tires do the trick? I think they may, given that they are all heavy-duty and high-quality.
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Old 05-11-2021, 07:12 PM   #13
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Well, if you'd need something bigger, would these 30 inches rims and tires do the trick? I think they may, given that they are all heavy-duty and high-quality.
First, the 30" wheels, before you even put a tire on the rim, is about 3" greater in diameter than any 15" trailer tire assembly and 2" greater diameter than most 16" trailer tires. Lack of wheelwell clearance is always an issue with any increase in tire/wheel diameter. Then, trailer tires almost always have a sidewall height of 75% or 80% of the tread width. That "taller tire sidewall is an important part of absorbing road shock to prevent trailer damage. Remember that most travel trailers do not have shocks, making the tires and springs the only means to absorb the stress of towing on "less than perfectly smooth roads".

Installing 30" wheels on an RV would mean "1-2 inch tire height, something that would "shake a trailer apart in just a few miles"....

It might "look great" to some, (not to great to others) but in execution, I don't see any way it would be beneficial to the trailer longevity...
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Old 05-11-2021, 09:02 PM   #14
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Quote:
Originally Posted by RandyCougar View Post
I have a 2003 Keystone Cougar that has 205/75/15 tires. They are 6 ply rated I think. As I get ready to travel this Spring, I want to have the best possible tires on it. I went to Les Schwab and asked if I could put 225's and get a 10 ply tires. They said I could not.

Interested in what others have found out.
Another tack...

The first question is; will a ST205/75R15 LRD with 2150# of load capacity give you 10% in excess load capacity above your vehicle certified GAWR axles? (Vehicle Certification label).

If the LRD tire will not satisfy the 10% RVIA load capacity reserve recommendation, ask Keystone for a size recommendation that will.
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Old 05-12-2021, 05:53 AM   #15
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This has been quite the saga. I ordered tires on Amazon. Based on Reviews I opted for Maxxis M8008 tires. Waited a week and they came in. Problem...the build date on them was 4815! Nearly 5 1/2 year-old tires, and they were on 8-ply, not 10. That's not going to happen. Requested a return and they reviewed it for 2 days and sent me return stickers. The kicker is I had to take them to a FedEx facility. They would not pick them up. The facility is more than and hour away from me. It will take a week for them to get back to Missouri. Then they will process my refund.

SO, I opted 225-75-15's and new wheels at my local Les Schab. A couple of hours after I dropped the trailer off at the shop, I got a call that they had mounted the tires on the wheels and that they absolutely DID NOT fit. He said that the shackles would have to be reversed and then MAYBE they would fit. He said I could come and look to verify. Since I was that hour north making the return, I asked for alternatives. He suggested I get Towmaster 8-ply rated 205-75-15's, and he would do the dismount/re-mount.

That is what I chose to do since we are getting ready to hit the road this weekend. On the way to pick up the trailer my wife's TPMS light came on in her van. Since we were at the tire store, I asked them to look at it. Turns out she had a drywall screw in one tire. Since we were at that point drop-ins, we had to wait our turn. Two hours later we left with Both vehicles. It turned out to be and all-day ordeal.

As a side note, the Maxxis tires came through Amazon and were from Autoplicity in Kansas City, Mo.
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Old 05-14-2021, 04:41 AM   #16
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I upgraded my Outback to 16" wheels and Cooper LT tires. Discount Tire had no issue with doing it.
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Old 05-16-2021, 08:00 AM   #17
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I upgraded my Outback to 16" wheels and Cooper LT tires. Discount Tire had no issue with doing it.
DT is normally very good about following USTMA tire standards and will not change tires with different size designations without some sort of vehicle manufacturer approval. It's a complete misapplication of those LT tires to do so.

Did they do the change on the vehicle and put it's vin on the bill of sale?

Without the vehicle being present, DT does not have to worry about liability and will sell to the consumer's wishes.
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Old 05-16-2021, 08:11 AM   #18
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Originally Posted by CWtheMan View Post
DT is normally very good about following USTMA tire standards and will not change tires with different size designations without some sort of vehicle manufacturer approval. It's a complete misapplication of those LT tires to do so.

Did they do the change on the vehicle and put it's vin on the bill of sale?

Without the vehicle being present, DT does not have to worry about liability and will sell to the consumer's wishes.

I can verify that they won't exceed approved sizes for a vehicle in my experience - been told no twice over the years. Both times they had the vehicle and I wanted new upsized tires....just wanted ones too big.....even though the ones they were taking off were the size I was requesting (put on by an individually owned shop in another town).
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Old 05-17-2021, 11:34 AM   #19
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Following the tire "IED" incident of two weeks ago& the total destruction of my Hideout's left wheel well & surrounding areas I am looking to purchase 10ply replacements. Same size, but 10ply. From what I have read Carlisle is the brand to go with. All comments welcome.
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Old 05-17-2021, 01:29 PM   #20
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I upgraded to Carlisle Radial Trail HD tires on my last trailer and was completely happy. If you are upgrading in load range will your wheel support the higher 80psi?

Also, if you have to rebuild your wheel well I would recommend going back with something other than luan and darco fabric.
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