Trailer weight -- hitched or unhitched?

[Launce]

I am a new owner of a used 16' Sport. I just went to my local truck stop and got a series of weights, loaded as planned for a trip.

The total weight was 8100 pounds. The tow vehicle weight, unhitched, was 4420. Subtracting (I wasn't going to unhitch the trailer on the scale with a semi behind me!) that tells me the trailer, unhitched, would be 3680.

I went through a bunch of times -- I couldn't get all 3 axles on separate scales -- and figured out that my trailer weight, hitched and with weight distribution bars in, was 3100 pounds.

So the GAWR for the trailer is 3500. If I use the unhitched axle weight of 3680, I'm 180 lbs over. But if I use the hitched axle weight of 3100, with some of the weight shifted to the TV, then I'm under by 400 lbs.

Here's my question: Am I over or under? Seems to me 3100 pounds is the actual weight of the trailer, when it's hitched and the weight distributed, and I'm OK. But maybe that's wrong.

[Bill M.]

If I read it correctly the trailer weighs 3680 when loaded against a GVWR of 3500 so the trailer is 160 over its max load. The trailer wt is just that, the trailer wt while unhitched.

The 3100 lbs is the actual load on the trailer ales when hitched. Part of the weight is being carried by the TV. There is a separate line on the trailer weight tag that gives the maximum wt rating for the axle. You need to check to see if you are over on the axle wt also. Compare the 3100 with the axle loading. I would not want to be over that number.

But you are definitely over the GVWR for the trailer. Sounds like it is time to lighten up a little or move some stuff to the TV. You might also check your tanks to see if you are carrying more fresh water than you need or some waste water. 20 gallons of water in any form (fresh, waste, cokes, etc) weighs about what you are over by.

The smaller trailer means you have to carry less of the same stuff that goes into the bigger ones. Add water and heavy groceries when near the campsite. No books or magazines at all. We got some folding chairs that weigh just about a lb each and take almost no space. We do not generally carry a grill.

[dkottum]

Looks like the trailer is overweight by 180 lbs when sitting there unhitched, that's nothing meaningful. When hitched all is well with the axles, and that's how we travel. I don't see the problem.

[Launce]

Originally Posted by Bill M.

If I read it correctly the trailer weighs 3680 when loaded against a GVWR of 3500 so the trailer is 160 over its max load. The trailer wt is just that, the trailer wt while unhitched.

Yes, you're right that I may be mixing up my GVWR and GAWR for the trailer. I'll have to check that.

[USAtraveler]

From your description of weigh-ins, I assume you got the 3100# trailer weight by maneuvering your TV off the scale completely, leaving only your attached trailer on the scale. If that's the case, you are definitely under the GAWR limit.

BTW, even if the fresh water tank was empty when you did your weigh-in, filling it completely afterward should still not put you over the trailer's GAWR. I don't have documentary evidence, but it would be totally irresponsible (and likely in violation of a common standard) if a mfg...in this case Airstream...installed an axle that was not capable of handling the typical weight of a fully loaded trailer with all its usual equipment, including a full fresh water tank. Of course if you happen to throw in an extra several hundred pounds of entertainment center, camping equipment, and a generous contribution to the next canned food drive, that's on you, not Airstream.

[Launce]

Originally Posted by USAtraveler

From your description of weigh-ins, I assume you got the 3100# trailer weight by maneuvering your TV off the scale completely, leaving only your attached trailer on the scale. If that's the case, you are definitely under the GAWR limit. .

The thing with the CAT scale was that the rig was short, so I always ended up with two axles on one pad. The 3100 for the hitched trailer was from having both TV axles on one pad, the Airstream on another, so it's a good weight. I came back around and pulled my front wheels off the scale to get separate front and back readings on my TV axles. Then I did it without the spring bars in the hitch. So I was there for a while!

I did have a full fresh-water tank. I wanted to see where things stood if I was set up for dry camping.

I guess the question is whether, when you calculate whether you're overloading the trailer, you count the tongue weight -- in my case, the 580 lbs (3680 - 3100) that is being transferred from the trailer axle to the tow vehicle when I'm hitched. (And also whether I add that 580 lbs to the TV when I'm calculating whether it's overweight.)

I read somewhere online that in calculating overweight fines (not an issue for me -- I'm too light any way you slice it), some jurisdictions add in tongue weight and others don't.

I mean, the rig seems stable in normal operation. But then a lot of this is about what happens when you have to slam on the brakes or swerve in an emergency, right?

So probably I should be conservative and try to trim down the TT weight. I have a little leeway to transfer some stuff from the trailer to the TV (a Nissan Xterra) to balance things out.

Thanks for the comments.

[Bill M.]

RV's are not regulated by DOT, at least in our state and I think everywhere, so no problem with fines. What is your gross axle rating? That is the number that many commercial checks use. Compare the 3100 to the gawr and let us know how that compares.
Sounds to me like you are just fine. A little over when running fully loaded. When you are doing a cross country and a lot of driving you could run less fresh water.
The numbers I would really want are the axle load (your 3100 lbs) and the rear axle load on the TV.

[PKI]

Disclaimer - do not know what the tire experts and RV masters would say, but IMHO you would measure the coach axle weight connected/hooked.

The reason is that we use static values (not moving) to predict the forces involved when we go dynamic (moving down the road). There is not the same load at rest that there is when moving. And stable movement loading is greatly increased by the vertical acceleration of hitting a bump. That bump greatly increases the force on the axle bearings, axle, tires and suspension. So engineering calculations assume that for a given static load, there will be more forces applied when in use. It is why trucks and trailers are required to have higher load tires. They generally see more rugged service.

Now, there is good reason to tune your load. All significant weight carried in the coach should be placed as low as possible and as close to the axle as possible. A jug of water can be placed where it is best needed to balance the load (it may be a loose mass if not secured). The water tank is located where it was designed to fit and that may be best or not so good depending on your load out. Moving weight from the coach to the center of your tow vehicle can reduce the amount of weight distribution needed to return design weight to the front axle. Do not place weight behind the rear axle of the TV as that practice requires more weight distribution force.

Moment arm is the force of a weight amplified by the distance the item is from the center of the vehicle. Reducing the weight or the distance from the center reduces the moment and makes a rig more stable. This is the primary reason for tuning the load. It is all a compromise. Traveling light by leaving items at home is best, but not if it makes your trips less enjoyable. Food can be purchased on the road. Clothing purchases are more difficult, but weigh less and therefore are usually an acceptable add. Water is heavy, usually available, but always needed in some quantity. The dutch oven is heavy and might best be left at home except for that special trip where it is a must have. The thoughtful compromise solution is the winning solution.

Be aware that items in the tow vehicle can be hazardous in an accident. Careful and secure storage is key to safe load out.

Off loading weight for storage is a good idea too. Empty the tanks and store gear in easily transportable boxes. Helps with first in first out consumption and keeping it all organized.

Never travel with an overloaded axle, tire or hitch. Travel safe. Pat

[Launce]

I had to go check my trailer in the storage lot and forgot about following up on this thread.

The answer to the question about the GAWR is that it's the same as the GVWR: 3500. I guess that's because it only has one axle.

[Boxite]

If it makes you feel any better, the 2012 16' Sport has a 4500lb rated axle. While certain other components and design-features may limit the GVWR.... it's not the axle which is limiting.

[larry9000]

We just got a 16' 2006 Bambi. It also had the GVWR and GAWR at 3500, so we had the same issue. With a full load of fresh water and propane, there was only 71 pounds to spare to the GVWR. I convinced myself that the GAWR was the real issue. With 400-500 pounds of tongue weight, a WD hitch will spread that (worse case) evenly between the TV and the Bambi's rear axle. That gained 200-250 pounds carrying weight, making the effective GVWR 3700 to 3750. The issue then becomes how much you trust the GAWR spec. Two Goodyear Marathon or other C rated tires allow a combined load limit of 3870. This was too close for comfort for me, so we swapped out our tires to the Goodyear Endurance D rated tires. At 2200# capacity each, they now have a combined load rating of 4400# (when run at 65 psi).

[uncle_bob]

Hi

Something else to consider: If you ever had a problem on the road and lawyers get involved, the specified ratings will probably come up. If they can argue that you were "over the limits", you are in for a really rough time. If you are over and *know* you are over, it's likely to be even rougher.

Again, this is only something to consider. I'm not in any way suggesting that this is anything other than a very remote possibility. Accidents and insurance claims are *not* an everyday happening. I've been known to do a number of things that involve risk (I've crossed streets in the middle of the block ... yikes !!!).

Bob

[Launce]

I'll look into changing out the tires. Seems like the axle is not the limiting factor, but the tires may be.

So ... I've basically been making the plaintiffs' case for them? Oh well, ignorance was bliss. You'll all testify for me, right?

Seems like ever since I started this thread, all I've thought of is cool, heavy stuff to add to my rig. I've taken to camping naked, but that doesn't seem to help much.

[larry9000]

...or you could upgrade wheels and axle to get 4300 GVWR. That's a lot of extra margin. Problem solved. The Canadian version had this for several years. So did the DWR.

[uncle_bob]

Hi

Tires *are* something that do fail on a depressingly regular basis. Maybe not quite as often as they once did on the better brands. Unfortunately the mechanisms that wear the out are hard to monitor. One set will go for 40 years (yikes!!) and indeed the set next in line failed in 4 years. These days, there are a very wide range of tires to pick between.

Bob

[Boxite]

Uncle Bob...just saw you are in Carlisle.... nice area. Full of history as well.

Back to the topic tho'.... the "lawyer" scare tactics don't impress me much. Can you point to a case where lawyers questioned GAWR, GVWR, tongue wts, etc. in any case involving a private individual towing a travel trailer?
I think you will waste a lot of time researching that.
The reason I bring it up is that there are so many posts in various threads which bring up the "lawyer scare" matter in an effort to swing someone over to a particular viewpoint, and it irks me. In my profession I saw that argument for 60 years and it simply never happened. It's a non-lawyer which usually raises that imagined spectre.

A lawyer will usually consider what the "prize" is. A private individual with a travel trailer who suffers a tire failure is an unlikely person to finance a hefty win in a lawsuit claim. The individual will have insurance and that company will pay for damages and that is all there is in that turnip.

You'll have to sell that "lawyer" thing to someone else, IMO. No offense intended.

BTW, back to the OP question: The axle of that trailer is undoubtedly rated at much higher wts than the tag riveted to the trailer. (I'm not suggesting anyone deliberately exceed ratings... I'm only saying there's little reason in measuring things with a micrometer, marking it with a grease-pencil if your cutting it with a hatchet. Which is what we do when the wife packs the bags and we head off to the RV park.)

[uncle_bob]

Hi

I've certainly seen cases (as in been there) where general loading issues were brought up. Weather they were a deciding factor, that's a completely different question. The argument didn't impress me or the rest of the jury very much.

Bob

[Launce]

OK.

At the risk of entering tire-rating hell, could I replace the 14" tires on my 2012 16' Sport with 15" wheels and D-rated tires without special modifications (e.g., clearance issues)?

In other words, unbolt the old wheels and bolt on the new ones? Get them balanced ...

Or if I want D-rated tires, should I stick with the 14" wheels?

I don't want to get into the ST v. LT debate. Assume I'm sticking with ST.

[larry9000]

Launce. That is a great question, and one we faced when we bought a 2006 16' Bambi last week. We decided to stay with the 14" but put on Goodyear Endurance D rated tires. It increases the margin quite a bit, up to D rating at 65 psi. I think that's like 4400# on a single axle trailer. It was the easiest and lowest price solution, and I added TPMS to monitor them. No complaints for the first 300 miles. But, the GYE are new and without a track record.

[gregwall]

Originally Posted by Launce

Yes, you're right that I may be mixing up my GVWR and GAWR for the trailer. I'll have to check that.

It's confusing. This video is nicely done:

https://www.youtube.com/watch?v=Umc0ZOFwl-E