Axle rating vs GVWR

Weight management is something all of us hauling RV trailers need to learn.

Lets say a trailer builder puts 4000# axles on it when 3500# axles will suffice. To many owners, that would invite overloading.

The regulations are clearly defined as to GVWR, GAWR and hitch weights. They are not derived from manufacturer standards. They are minimum regulations the manufacturer must follow. To build trailers with excesses would further invite overloading. It’s the owners responsibility to manage their weights.

All of today’s RV trailers invite overloading. Here is a quote from NHTSA about it.

“The FMVSS have requirements for the manufacturer to use proper tires and rims for the gross axle weight rating (GAWR) and the gross vehicle weight rating (GVWR). The manufacturer may determine the GVWR by adding cargo capacity (if any) to the curb weight of the vehicle as manufactured. The wise consumer, before purchase, will determine if the vehicle has sufficient cargo capacity to carry the weight of water, additional equipment (such as televisions, and microwave ovens), and luggage. The manufacturer’s certification label must show the GVWR. The GVWR must not be exceeded by overloading the vehicle. There is little the government can do to assist a consumer who has purchased a vehicle that has insufficient cargo capacity for its intended use.”

FastEagle

Longtrace wrote:
The tow vehicle will be carrying some of the weight until a weight distributing hitch is involved.

The TV will be carrying all of the tongue weight if a WDH is not used.

Without any real data and just going off the theory, about 50% of the distributed weight will end up on the trailer axle(s).

I've compiled and analyzed a lot of real data. Typically, a WDH will be adjusted to transfer a load equal to about 15-25% of tongue weight to the TT's axles.

Ron

ktmrfs wrote:
Note: WD does NOT change tongue weight, it only shifts weight from the TV rear axles to the TV front axle and trailer axles.

Correct. And so it's not correct to subtract all the tongue weight from the gross weight to determine the load on the axles - if a weight distributing hitch is used.

Longtrace wrote:
The tow vehicle will be carrying some of the weight until a weight distributing hitch is involved.

The whole purpose of a weight distributing hitch is to transfer weight from the back axle of the tow vehicle to the trailer axle(s) and the tow vehicle steer axle.

Without any real data and just going off the theory, about 50% of the distributed weight will end up on the trailer axle(s).

My trailer is the same way. According to the weight vehicle label, the axles are rated for 600 lbs less than GVWR. Which is about the the tongue weight. (2800 lb/ axle) However, I think the weigh rating on the axle itself is 3500 lbs.

yes, WD hitch will transfer TV weight to the trailer axles. calculating how much is fairly lengthy. My experience on two vehicles is that about 30% of the tongue weight is about how much of the TV weight is transferred to the trailer axles. Each case is different, about the only way to know for sure is to measure axles weights with and without WD hooked up. Note: WD does NOT change tongue weight, it only shifts weight from the TV rear axles to the TV front axle and trailer axles.

The tow vehicle will be carrying some of the weight until a weight distributing hitch is involved.

The whole purpose of a weight distributing hitch is to transfer weight from the back axle of the tow vehicle to the trailer axle(s) and the tow vehicle steer axle.

Without any real data and just going off the theory, about 50% of the distributed weight will end up on the trailer axle(s).

My trailer is the same way. According to the weight vehicle label, the axles are rated for 600 lbs less than GVWR. Which is about the the tongue weight. (2800 lb/ axle) However, I think the weigh rating on the axle itself is 3500 lbs.

93Cobra2771 wrote:
Guess I'm the oddball of the bunch - 10,000 GVWR with two 5300# axles.

me to, 8600lb GVWR with two 4400lb axles. Not as much margin as you, but still axles can carry full GVWR.

Guess I'm the oddball of the bunch - 10,000 GVWR with two 5300# axles.

Which is another way of saying the trailer manufacturer is cheapening out. They do the bare minimum they can get away legally.

ChooChooMan74 wrote:
7500lbs - 750lbs or more tongue weight < 7000lbs on the axles.

Searching_Ut wrote:
I have a 2012 240 RKS, and not only did they give you plenty of axle, they also gave you several thousand pounds of extra tire capacity, the lack of which is one of the main reasons people experience tire failures on ST tires in my opinion. The "buffer" really helps on rough roads, tight corners etc where you're really pushing suspension components.

Yep, one of the reasons we intend to look at the 240RKS this summer on our travels across the continent. The main reason, though, is that the wife really likes the floor plan and all the insulation.

brulaz wrote:
Trailmanor does the same thing. I've got a single 3500# Dexter axle under a trailer with 4230# GVWR. And, the posted GAWR is not 3500# but 3619#, since Trailmanor believes the weight of the wheels and tires do not count. It's all part of making an extreme light weight trailer.

Other companies are much more conservative. Keystone puts 4400# axles under some smaller Passports, Cougars and Laredos. The Northwood Mfg. and Outdoors RV puts 5200# axles under some of theirs. The Outdoors RV Timber Ridge 240RKS has two 5200# axles and GVWR of 8100#. THat's one reason why these trailers are considered more rugged than the light-weights.

I have a 2012 240 RKS, and not only did they give you plenty of axle, they also gave you several thousand pounds of extra tire capacity, the lack of which is one of the main reasons people experience tire failures on ST tires in my opinion. The "buffer" really helps on rough roads, tight corners etc where you're really pushing suspension components.