Question about G versus H tires

[shane wood]

Originally Posted by fiddleddd

Hello everyone,
I read some threads on tires, but I'm just as confused as ever. We're getting ready to buy a Redwood fifth wheel, and we're not sure which tires to go with. The Redwood rep told us we didn't need H tires, but then he also said the following: "The H tires come with 8000 lb. axles.....they are bigger tires than the G's, and also have bigger rims and drums. Therefore they will stop better than G tires". ??? Really? He recommended either going with disc brakes and G tires or H tires without the disc brakes because they are supposed to enable us to stop better. Can someone please weigh in on this? Which tires would you recommend? The unit we're buying has a GVWR of 16,500 and comes with Falcon 7000 lb. axles. Thanks so much!

You are getting the 38GK I would go with 800lb axles with H Goodyear's. Make sure you get disc brakes these trailers are heavy. My RL has a heavier pin weight than yours and my 2015 GM Drw handles it great. My pin weight is 4220lbs and I still have room to spare on weight

[Tireman9]

Originally Posted by fiddleddd

Hello everyone,
I read some threads on tires, but I'm just as confused as ever. We're getting ready to buy a Redwood fifth wheel, and we're not sure which tires to go with. The Redwood rep told us we didn't need H tires, but then he also said the following: "The H tires come with 8000 lb. axles.....they are bigger tires than the G's, and also have bigger rims and drums. Therefore they will stop better than G tires". ??? Really? He recommended either going with disc brakes and G tires or H tires without the disc brakes because they are supposed to enable us to stop better. Can someone please weigh in on this? Which tires would you recommend? The unit we're buying has a GVWR of 16,500 and comes with Falcon 7000 lb. axles. Thanks so much!

Good question but some facts are being confused because we don't have all the needed information.
"G" and "H" refer to the tire Load Range or what use to be called Ply Rating. You can definitely find tires of the same size in different Load Range but you didn't include the specific tire size(s) being offered so there is a lot of guessing here.
Load Range is an indication of the maximum air pressure the tire is designed to handle when cold and since it is the air pressure that supports the load a tire with greater pressure can support more load than another tire of the same size but lower Load Range.
Now as to axle rating. It wasn't clear if the trailer certification label would be changed by the Mfg or dealer but if there is an axle change I would expect this to be a Mfg change so the placard should be different on a TT with an 8000# axle than one with 7000# axles. You do need to learn if the GAWR and GVWR for the "upgrade" will also be upgraded as higher GAWR & GVWR would normally translate to more load carry capacity for the TT.

RE brakes. I would prefer disk brakes but it sounds like the improved tires & axle do not come with the better brakes so this would make the move to drum brakes a downgrade IMO unless there is published data showing better (shorter) stopping distance with drum brakes. NOTE shorter stopping may be possible on a single stop but repeated stops or slowing on long downgrades would definitely be better with disk brakes based on general automotive experience and history. Is the salesman willing to provide supporting data on stopping for the two different setups?
I do find it improbable that a heavier TT (with heavier axle & GVWR) would stop better with drum brakes than a lighter TT with disk brakes. This just doesn't match the science of vehicle braking technology.

To learn more about tires in general you might want to check out the information in my tire blog.

[Dale & Mark Bruss]

Originally Posted by wingnut60

"All tires at the time of first sale MUST be the same size as those listed on the certification label."
There must be hundreds of dealers facing severe penalties, maybe prison time, for upsizing the tires on a new trailers at the time of the 'first sale.' I can't imagine a more serious crime....the courts will be crowded as soon as NHTSA is made aware of these transgressions.

I looked at several NHTSA and all they refer to is adequate tire for the certification.

I see nothing in the NHTSA documents about having tires with more capacity being an issue. I really wonder who would try to say that having more tire capacity at time of sale is a problem.

[jdpm]

Originally Posted by FastEagle

You’ve really got me curious now. You see, once we own the vehicle things are different. For the vehicle manufacturer and dealers, safety things are mandatory and NHTSA has huge monitory penalties for those that bend the rules.

To reestablish the GVWR a lot of things must happen. One that is often overlooked is the RV trailer manufacturer’s established hitch/pin weight. It’s a mandatory measurement in establishing GVWR. They can’t be wishy-washy about it, they Must publish it. (Sometimes - almost always - a GVWR increase that large will require a trailer hitch replacement).

The axle manufacturers’ established load capacity on their axle tag does not always reflect the vehicle manufacturer’s established GAWR for that axle.

All axle GAWR values depicted on the RV trailer’s certification label when added to the vehicle manufacturer’s hitch/pin weight MUST equal or exceed the trailers GVWR.

All tires at the time of first sale MUST be the same size as those listed on the certification label.

The vehicle manufacturer established hitch/pin weight is normally found in the sales brochure and in the vehicle owner’s manual.

Another thought, The mandatory cargo capacity label must also be changed to reflect the new cargo capacity.

All of that stuff is binding because you have a new certification label. Hopefully somebody was certified to do it and all the loop holes were properly threaded.

On edit: Found the hitch weight for a LS36FW. It's 2964#.

I scaled my 2014 LS36fw with empty holding tanks, 1/4 tank of fresh water and backed for a 3 night trip. Unit has no genset or w/d. Came in at 3400lbs.

[FastEagle]

Originally Posted by Tireman9

Good question but some facts are being confused because we don't have all the needed information.
"G" and "H" refer to the tire Load Range or what use to be called Ply Rating. You can definitely find tires of the same size in different Load Range but you didn't include the specific tire size(s) being offered so there is a lot of guessing here.
Load Range is an indication of the maximum air pressure the tire is designed to handle when cold and since it is the air pressure that supports the load a tire with greater pressure can support more load than another tire of the same size but lower Load Range.
Now as to axle rating. It wasn't clear if the trailer certification label would be changed by the Mfg or dealer but if there is an axle change I would expect this to be a Mfg change so the placard should be different on a TT with an 8000# axle than one with 7000# axles. You do need to learn if the GAWR and GVWR for the "upgrade" will also be upgraded as higher GAWR & GVWR would normally translate to more load carry capacity for the TT.

RE brakes. I would prefer disk brakes but it sounds like the improved tires & axle do not come with the better brakes so this would make the move to drum brakes a downgrade IMO unless there is published data showing better (shorter) stopping distance with drum brakes. NOTE shorter stopping may be possible on a single stop but repeated stops or slowing on long downgrades would definitely be better with disk brakes based on general automotive experience and history. Is the salesman willing to provide supporting data on stopping for the two different setups?
I do find it improbable that a heavier TT (with heavier axle & GVWR) would stop better with drum brakes than a lighter TT with disk brakes. This just doesn't match the science of vehicle braking technology.

To learn more about tires in general you might want to check out the information in my tire blog.

In the options section of the trailer in question the manufacturer offers the 8000# axles and 17.5" Goodyear tires. It's their offer to do with as they see fit. They do not say the GAWR or GVWR or cargo and hitch weights will be adjusted. All they are doing is making a weak link stronger.

[FastEagle]

Originally Posted by jdpm

I scaled my 2014 LS36fw with empty holding tanks, 1/4 tank of fresh water and backed for a 3 night trip. Unit has no genset or w/d. Came in at 3400lbs.

As I said above, the manufacturer's established hitch pin value is only used as a measuring tool when they establish the units GVWR. Once the trailer is sold the hitch pin weight is the sole responsibility of the vehicle owner.

[FastEagle]

Originally Posted by wingnut60

"All tires at the time of first sale MUST be the same size as those listed on the certification label."
There must be hundreds of dealers facing severe penalties, maybe prison time, for upsizing the tires on a new trailers at the time of the 'first sale.' I can't imagine a more serious crime....the courts will be crowded as soon as NHTSA is made aware of these transgressions.

It’s a procedural thing. Up until a vehicle is sold NHTSA has the authority to insure the vehicle complies with all safety regulations in effect at the time of the sale. The vehicle manufacturer is saying just that with the certification label.

Dealers can replace a certification label before first sale with a corrected one authorized by the vehicle’s manufacturer. After the sale, auxiliary tire information can be displayed adjacent to certified placards to display any tire changes with different sizes and inflation pressures. Without vehicle manufacturer approval vehicle warranty coverage can be effected.

This is an excerpt from FMVSS 571.120, paragraph S10.3, “The tires on each motor home and RV trailer at first retail sale must be the same size as the tire size on the labeling.”

That’s a safety standard vehicle manufacturers MUST abide.

[wingnut60]

Ahhh, FastEagle,
Between the NHSTA and their FMVSS books, you must stay pretty busy keeping up...
I was TRYING to be impart some levity in my comments, just to offset your seriousness.
Joe

[Tireman9]

Originally Posted by jdpm

X2
We ordered our Lifestyle with the 8k axles, disc brakes and 17.5 wheel/tire set up. Our payload was increased by the manufacture 2k pounds due to the 8k axles.
Overkill really for our application but I did it for the safety margin.
I had the G614 tires on the previous fiver. I opted to go with the 17.5 set-up due to the lack of problems associated with them. You will rarely read of an issue with the 17.5 ties.....the G614 has an issue now and then. Plus the 17.5 tires are more widely available due to not only Goodyear being
a manufacturer BUT Continental, Michelin, and Hankook to name a few.

Sounds like a good plan to me given that most TT on the road have tire and / or axle in overload.