What I learned, and now, know about tires!

[sourdough]

This is a little late but wanted to share some stuff I've learned in the last few days after getting worried about the tires that came on my new 319RLS.

I was concerned about the weight of my trailer on the tires provided as mentioned by OP. GVWR is 10,000 lbs. Each tire read max. load was 2200 lbs which is a problem. I contacted Keystone and their initial response was the tires were correct - the weight carried by the hitch had to be taken into account. That didn't seem right so did some research and here is what I found.

When you are talking to a dealer or manufacturer about trailer/tire issues tell them to forget the hitch consideration in their explanation. Federal law does not mention the transfer of hitch weight. It specifically states that the tires MUST be able to carry at least the maximum GAWR of the trailer - no hitch exceptions (NHTSA Code of Regulations; Title 49; Transportation; Section 571.110; S4.2.2.1). In one of the transcripts it also mentioned a proposed requirement for a 15% safety margin but I could not find that in actual law..yet.

I talked to the Keystone technical manager that works with the tires/ratings etc. and he seemed very knowledgeable. I quoted him the regulation and told him they, and I, had a problem. I had already told him I was going to call the NHTSA and advise them Keystone was putting inadequate tires on their units. As we discussed it he really was concerned that I had a 2200lb rating on each tire vs the 10,000lb weight. I told him I would recheck the tires. Well, my old eyes and quad focals did not initially see I was looking at the dual rating. The single rating was 2540 which put me at 10,160lbs. My GAWR? 10,160lbs! Not much margin if you max it out, which I don't intend to, but still one should really think about that and keep tires uppermost in your mind on a trip.

[ocho]

Originally Posted by sourdough

This is a little late but wanted to share some stuff I've learned in the last few days after getting worried about the tires that came on my new 319RLS.

I was concerned about the weight of my trailer on the tires provided as mentioned by OP. GVWR is 10,000 lbs. Each tire read max. load was 2200 lbs which is a problem. I contacted Keystone and their initial response was the tires were correct - the weight carried by the hitch had to be taken into account. That didn't seem right so did some research and here is what I found.

When you are talking to a dealer or manufacturer about trailer/tire issues tell them to forget the hitch consideration in their explanation. Federal law does not mention the transfer of hitch weight. It specifically states that the tires MUST be able to carry at least the maximum GAWR of the trailer - no hitch exceptions (NHTSA Code of Regulations; Title 49; Transportation; Section 571.110; S4.2.2.1). In one of the transcripts it also mentioned a proposed requirement for a 15% safety margin but I could not find that in actual law..yet.

I talked to the Keystone technical manager that works with the tires/ratings etc. and he seemed very knowledgeable. I quoted him the regulation and told him they, and I, had a problem. I had already told him I was going to call the NHTSA and advise them Keystone was putting inadequate tires on their units. As we discussed it he really was concerned that I had a 2200lb rating on each tire vs the 10,000lb weight. I told him I would recheck the tires. Well, my old eyes and quad focals did not initially see I was looking at the dual rating. The single rating was 2540 which put me at 10,160lbs. My GAWR? 10,160lbs! Not much margin if you max it out, which I don't intend to, but still one should really think about that and keep tires uppermost in your mind on a trip.

There in lies the rub. Imagine what us toy hauler folks do. They give us just enough tire to haul the thing off the lot. If you put toys in your new toy hauler, well that's your problem.

I love the way Keystone will till you that its ok to "subtract" the tongue weight from the GVW to get an "accurate" weight of the rig so they can install two 7,000lb axles on a 16,500 lb rig. BUT, that same cant be said about the tire loading. If the tires are bolted directly to the axles, which most time they are, then the subtraction of the tongue weight "felt" on the axles will also be "felt" on the tires. Certainly then I must be able to "use" that 15 to 20% "reduction" that the two vehicle is carrying to, in effect, "increase" the weight carrying capacity of my tires.

Of course, I agree that the tow vehicle will carry some of the weight, and when ive weighed my TH's tongue weight, im right at 18 to 20%. BUT, I still think that the axle weight limits, and more importantly, (see my thread, Heads up folks, I just found a serious suspension fault), the hangers and shackles and the other components that attach that to this, are way under rated for the job they do.

This is the precise reason Im upgrading the entire suspension with Dexter axle components AND replaced the Chinese "E" rated tires with American made Carlisle "F" rated tires.

Its ridiculous that we as RV owner's have to "UPGRADE" to components that will satisfy the demands we expect from our RV's when they should have been installed in the first place.

BTW, I will file a report to the NHTSA for the broken axle components

[sourdough]

OCHO

The NHTSA has a hotline for complaints. I had talked to them prior to talking to the Keystone manager but did not file a complaint....I should have. Keystone, and most other RV manufacturers, apparently put the very least into the suspension/tires as they can. In you case I believe they are breaking federal law. You might look up the statute I referenced and read it thoroughly as it pertains to your situation. I had them on the hook for 5 E rated tires until I found out I can no longer read . If you find that they are in fact skirting the law I have the contact info for the Tech manager that is Keystone's liason betweent the company and U.S. DOT/NHTSA. You might push them to take care of your stuff. Don't hesistate to threaten a probe by DOT or NHTSA if you have documentation of their failure to follow the law, and remember, the hitch pin/tongue weight etc. etc. doesn't have a thing to do with anything except their attempt to confuse the issue.

[ocho]

Originally Posted by sourdough

OCHO

The NHTSA has a hotline for complaints. I had talked to them prior to talking to the Keystone manager but did not file a complaint....I should have. Keystone, and most other RV manufacturers, apparently put the very least into the suspension/tires as they can. In you case I believe they are breaking federal law. You might look up the statute I referenced and read it thoroughly as it pertains to your situation. I had them on the hook for 5 E rated tires until I found out I can no longer read . If you find that they are in fact skirting the law I have the contact info for the Tech manager that is Keystone's liason betweent the company and U.S. DOT/NHTSA. You might push them to take care of your stuff. Don't hesistate to threaten a probe by DOT or NHTSA if you have documentation of their failure to follow the law, and remember, the hitch pin/tongue weight etc. etc. doesn't have a thing to do with anything except their attempt to confuse the issue.

Would you mind sending the contact info at Keystone you spoke of? Also, the NHTSA contact? And if you have it available, the statute that speaks of the trailer weight issues. Thanks. Let yall know what i stir up!

[sourdough]

OCHO

Here is an excerpt from my correspondence with the Keystone tech manager:
"
I don't know how much of this you have read but for your own edification here is the law on tire requirements for RVs:

"S4.2.2Tire load limits for multipurpose passenger vehicles, trucks, buses, and trailers.S4.2.2.1Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle.

This is federal law. It comes directly from the Code of Regulations; Title 49 - Transportation; Section 571.110; S4.2.2.1. I'm not dreaming this up. The designation of trailer refers to RVs. Paragraph S4.2.2.2 provided as an exception speaks to putting passenger car tires on a truck, bus or trailer; which is not the case here. Note there are no exceptions for "tongue" or "hitch weight", which makes sense if they wanted a standardized law."

The contact at Keystone is Garett Carolus, technical manager, Keystone and Dutchmen Rv's, phone is 574-537-3925, email: [email protected]. I don't have the NHTSA number but I found it by googling contact numbers for them and complaints. The statute has many sections and there are other statutes as well that deal with various aspects of tires, wheels, weights etc.

Good luck and let us know.

[CWtheMan]

While building trailers the manufacturer has the leverage to set GVWR, GAWR and select tires and their air pressures for the GAWR. If you are unhappy with the cargo placard I’m sure Keystone would gladly reduce it for you so you can get to the proper GVWR. They also have the obvious advantage of deducting the hitch weight from the GVWR so they can set the GAWR they intend to use for the final product.

Keystone has had a reputation of often setting GAWRs for the sole purpose of tire selection. An example is fitting 5200# axles to a trailer and then setting those axles at 5080# GAWR to fit tires rated at 2540# on those axles. Perfectly legal but not very ethical - IMO. Many Marathon tires failed in those circumstances.

In the 571.120 regulation the use of hitch weights is an integral part of the process to set GVWR and GAWR. Here is an excerpt from that regulation -- “S10.2 On RV trailers, the sum of the GAWRs of all axles on the vehicle plus the vehicle manufacturer's recommended tongue weight must not be less than the GVWR. If tongue weight is specified as a range, the minimum value must be used.”

The 15% reserve rule has been roaming around in many of the tire forums. I suspect it’s something someone read in the proposed rules changes of 2007. It was proposed by the RMA and supported by others but the NHTSA rules committee turned it down. Ever since then the RMA has unofficially recommended 12-15% in their publications. IMO it’s a good recommendation. Time and experience has proven that RV trailer tires need lots of extra load capacity reserves to survive to a given life expectancy.

CW

[Bigg-limo]

I like fact that the Carlisle tire has a pretty high load capacity, especially for a 16" tire. However,...I often wonder about the the actual rubber compound of the tire itself. For instance, I'm running Goodyear G947 RSS's on my Fuzion 399 right now. When I'm "loaded," I'm right at Gross on the trailer, but I'm only 15K lbs on the trailer axles. The load capacity is 3042 lbs. My axles are 7k lb axles. I know that's obviously almost a thousand pounds difference in capacity between the two, but for us with triple-axle trailers, the tires that i've seen hold up, are the ones made with a compound that's more designed for commercial use. The tread is harder, and they usually have deeper tread too. The tread seems to hold up better from all the scrubbing that occurs when turning. Don't get me wrong, I think that Carlisle makes a good enough tire that's always one of my top choices on my lighter trailers. I've ran them on my trailers with no problems, other than age and weather. I'd be interested in some of you guys' opinions on this. Just curious in what you think.

[bsmith0404]

I've run Carlisle tires on everything from a light ATV trailer to a 13k lb 5er and have never had a problem with any of them. Of course I always change them out between 3-5 years, stay within the 65 mph max speed rating, and keep the pressures up. I also park the trailers on 2x8s when not in use so they don't have the petroleum from the asphalt breaking them down, and keep them covered from the sun. I also use a rubber moisturizer on the sidewalls, although I often question the benefits of that.

[Got 88]

Originally Posted by ocho

After shredding two tires recently, the latest causing some minor damage, I've spent the last three weeks doing some in depth tire research. Here's what I came up with. Its all about load, load rating, pressure and temperature. I know sounds easy, and it should be, but I've read numerous post from several RV boards and was surprised how many threads there were on this topic. Tires are without a doubt the most overlooked yet the hardest working member on your team. They require the upmost of attention and any neglect will land ya on the side of the road.

There was also a lot of talk about the type of tire. LT vs. ST. I was surprised to see how many RV owners chose LT (light truck) instead of the ST (special trailer) tires that came on most if not all camping trailers. Fact is that while either of the two tires can be used on a trailer, they are completely different tires. ST tires are specifically designed for use on Travel trailers and 5th wheels. They typically will have a tougher sidewall and rubber compounds that resist heat. However, it usually comes down to the load rating on the tire.

I had load range E tires on my 300 mp when they blew. A couple of weeks ago I had a talk with Keystone to get some answers. I knew my exact weights of the trailer, the load in the garage, etc. They kinda beat around the bush and give canned answers to the questions I asked and could not get specific. Basically, they read from a sheet that the engineers give them. So I asked to speak with an engineer, the agent laughed, then caught herself. "Customers cant speak to Engineers" I asked why and was told, "well they just don't" Youd think I was asking to speak to God himself. Anyway, I eventually got enough information to make an intelligent decision.

Of the many things we talked about is how 14,000 lb axles could legally and safely carry my 300MP at a MGVWR of approx. 16,500 lbs. I don't recall the exact number but that is close. She had mentioned the percentage of the tongue weight that is reduced from the trailer weight, that's how they do it. So I say "The E rated tires you put on the trailer are certified to carry, on average, 3400lbs each". That's 13,600 lbs folks. Nearly 3000lbs less that the what the trailer is certified to carry. That's pretty scary. So I ask " then why cant the same tongue weight percentage be used to allow the tires to carry more than their certified to carry. Dead silence!! Hello? "Yes Sir, im here. I understand your question but I cant answer it". Uh huh, there's the answer. By loading my golf cart and Harley in the back with no water, no fuel for the Gen, and the usual things needed for a weekend camping trip im WAY over the weight limits for the tires. So just one thing wrong with any tire, like under pressure, over heated or as we see now, over weight and you run a high risk of blowing a tire.

It appears to me that the tires that come from the RV factories handle the shipping weight of the trailer just fine. Just don't load too much into it and you'll be fine. But, that doesn't work so well for a toy hauler. That's we buy them right? Answer? Put F or G rated tires on the damn things from the factory. Then your limitation becomes the axles. But, we've already seen that when you figure the tongue weight percentage that all changes.

Where am I going with all this? My fingers are sore, so here what I did. I looked further into tire manufacturers. I knew that I didn't want Chinese tires and LT tires weren't an option either. So my next call was to Carlisle Tire where I was quickly transferred to an actual Engineer!! My interest was the new Radial Trail RH. Size was the original ST235/85/16, but "F" load range. Now with each tire carrying 3950lbs each at 95 PSI I have 15,800 lbs I can carry with just the tires!!!! No longer will the tire be my limiting factor. "G" rated tires are available, but then your limitation becomes your aluminum factory rims. "G" rated tire run at 110 psi, but carry lots of weight.

Other issues have been brought up regarding the ST tires and why some choose LT tires is the speed limits. ST tire should be limited to 65 mph, but no longer. After speaking to the ENGINEER at Carlisle, he informed me that Carlisle will be lifting that limitation within the next couple months.

Now, after loading my trailer for that weekend camping trip as described earlier, im nowhere near my limitations, where as before I was at them. I just installed these new tires so I have yet to get them on the road, but ill let yall know. Im not affiliated with Carlisle tires nor am I an Engineer. Just a guy wanting to get from there to here with my toys safely as possible. This post is written because there is a lot of misinformation out there and folks that just may not know. I don't profess to be an expert and this is just my opinion.

I welcome yalls feedback!! Thanks, Ocho

I've also been considering going to a F or G rated tire, but after doing the math, I'm wondering if I really need to? I have a 2014 Raptor 297SE, 2 axles rated at 7k, haven't had it on the scales, so for now I'm using Keystone's specs. Dry weight 11,003lbs, max cargo capacity 4,397lbs = GVWR 15,400lbs. GVWR 15,400 minus pin weight 2610 = 12,790lbs, divided by 4 tires = 3,197lbs per tire. My E load tires are rated at 3,520lbs. Is this how I should be computing this? Again, I know I need to hit the scales to get confirmed weights...are Keystone's specs somewhat accurate? Any help or advice would be appreciated.

[canesfan]

Originally Posted by Got 88

I've also been considering going to a F or G rated tire, but after doing the math, I'm wondering if I really need to? I have a 2014 Raptor 297SE, 2 axles rated at 7k, haven't had it on the scales, so for now I'm using Keystone's specs. Dry weight 11,003lbs, max cargo capacity 4,397lbs = GVWR 15,400lbs. GVWR 15,400 minus pin weight 2610 = 12,790lbs, divided by 4 tires = 3,197lbs per tire. My E load tires are rated at 3,520lbs. Is this how I should be computing this? Again, I know I need to hit the scales to get confirmed weights...are Keystone's specs somewhat accurate? Any help or advice would be appreciated.

To try and answer your question re KS specs, my understanding has always been just like truck specs, they are for an empty, stripped down base model. Options and extras add to dry weight. My Raptor came in at ~800 lbs more than what the lit said. Also any changes KS may have made during the course of production could vary the weight.

As for your math, looks good to me, just remember each tire may not be carrying the same load.

I have the same axles and tire rating but mine has a GVWR of 16500. Talk about cutting it close.

[ocho]

Originally Posted by Got 88

I've also been considering going to a F or G rated tire, but after doing the math, I'm wondering if I really need to? I have a 2014 Raptor 297SE, 2 axles rated at 7k, haven't had it on the scales, so for now I'm using Keystone's specs. Dry weight 11,003lbs, max cargo capacity 4,397lbs = GVWR 15,400lbs. GVWR 15,400 minus pin weight 2610 = 12,790lbs, divided by 4 tires = 3,197lbs per tire. My E load tires are rated at 3,520lbs. Is this how I should be computing this? Again, I know I need to hit the scales to get confirmed weights...are Keystone's specs somewhat accurate? Any help or advice would be appreciated.

You may have all the tire you need. Im assuming that this is not a toy hauler and a bumper pull. When it come time to change the tires for whatever reason, you may want to upgrade, but I wouldn't go any more that the F due to the rim air pressure rating limitations. Check with your rims manufacturer to verify that rating. Im a big fan of having things over engineered than just adequate. There is not a lot of difference in price between the two, but a ton in peace of mind!! Hope this helps

[Got 88]

Originally Posted by ocho

You may have all the tire you need. Im assuming that this is not a toy hauler and a bumper pull. When it come time to change the tires for whatever reason, you may want to upgrade, but I wouldn't go any more that the F due to the rim air pressure rating limitations. Check with your rims manufacturer to verify that rating. Im a big fan of having things over engineered than just adequate. There is not a lot of difference in price between the two, but a ton in peace of mind!! Hope this helps

It's a 5th wheel toy hauler...wheels are rated for 110psi.

[ocho]

Originally Posted by Got 88

It's a 5th wheel toy hauler...wheels are rated for 110psi.

Sorry, I see that now. I had you confused with another post. Are they steel wheels? The reason I ask is my wheels are alloy made by Tirco. They are rated at 3580lbs@100 psi. That's why I went with the F rated tires. Plenty of overhead on the weight and at 95 psi, will work on my stock rims.

[Got 88]

Originally Posted by ocho

Sorry, I see that now. I had you confused with another post. Are they steel wheels? The reason I ask is my wheels are alloy made by Tirco. They are rated at 3580lbs@100 psi. That's why I went with the F rated tires. Plenty of overhead on the weight and at 95 psi, will work on my stock rims.

The wheels on my rig are made by Sendel...16x6, rated 3750lbs @110psi.

[ocho]

Originally Posted by Got 88

The wheels on my rig are made by Sendel...16x6, rated 3750lbs @110psi.

Tireco is the manufacturer. Sendel is the model name. Mine are the same but less weight capabilities.

www.tireco.com

I have the T03-66866BM** 16x6 8/6.5 +0 4.90 3580 @ 100 PSI .

I saw yours. Would have been nice of Keystone to put those on all their toy haulers!! We could then choose to upgrade tires without having to upgrade wheels as well.

[Got 88]

Originally Posted by ocho

Tireco is the manufacturer. Sendel is the model name. Mine are the same but less weight capabilities.

www.tireco.com

I have the T03-66866BM** 16x6 8/6.5 +0 4.90 3580 @ 100 PSI .

I saw yours. Would have been nice of Keystone to put those on all their toy haulers!! We could then choose to upgrade tires without having to upgrade wheels as well.

Which F rated tires did you go with?

[ocho]

Originally Posted by Got 88

Which F rated tires did you go with?

Carlisle Radial Trail RH. Read the firsts few posts of mine in this thread for more details. If you decide on them do what I did. I shopped them online, and hit up Discount tire to match them. Mine did, BUT, be vigilant with Discount tire. They first installed the E rated Carlisles but I caught it. I don't think It was intentional tho. Also, check Carlisle Tires website. Good info there. Also, they plan on lifting the speed limitations of that tire.

[Got 88]

Originally Posted by ocho

Carlisle Radial Trail RH. Read the firsts few posts of mine in this thread for more details. If you decide on them do what I did. I shopped them online, and hit up Discount tire to match them. Mine did, BUT, be vigilant with Discount tire. They first installed the E rated Carlisles but I caught it. I don't think It was intentional tho. Also, check Carlisle Tires website. Good info there. Also, they plan on lifting the speed limitations of that tire.

Did Discount have any issues/concerns with installing a tire rated at 3960lbs on your wheel rated at 3580lbs?

[ocho]

Originally Posted by Got 88

Did Discount have any issues/concerns with installing a tire rated at 3960lbs on your wheel rated at 3580lbs?

Nope. sho didn't!!

[lawdes]

I just got rid of my 14" factory tires and got the 15" Carllisle RH, upgrading to load rating E. Took a 2000 mi trip and they ran great...no problems at all.