Relationship between CCC and Tow Capacity?

[gstrohl]

In my efforts to determine the cargo carrying capacity of RVs that we might purchase I have been surprised by the range of values for CCC (from a few hundred pounds to few thousand pounds!).

Reading Holiday Rambler's brochure for the 2016 Ambassador, I came across this statement that struck me as not right. I would appreciate anyone's opinion on this.

"†† Minimum Towable Load is the available weight, up to GCWR, when the coach is fully loaded to maximum GVWR. However, if the coach is loaded to something less than maximum GVWR, that extra available weight can be added to your Towable Load. For example, if your coach is loaded to 1000lbs less than maximum GVWR, your Towable Load increases accordingly."

It's the latter half of the statement that didn't seem right to me.

First, should the first word of this statement read, "Maximum" and not "Minimum"?

Second, are the two load types very different and, thus their weights non-transferable?

I am no engineer, so I have no firm opinion other than a gut feeling that the statement isn't correct.

Gerry

[Old-Biscuit]

Minimum Towable Load is the available weight, up to GCWR, when the coach is fully loaded to maximum GVWR.

With coach loaded to GVWR then difference between GVWR and GCVWR is the 'minimum load' available

BUT with coach loaded to LESS then GVWR......difference between GCVWR & GVWR increases so minimum load increases

MAX Load Capacity would be more dependent on REAR Axle Weight Rating, Hitch/Receiver ratings.

CCC does affect tow ratings...the less CCC the less weight that can be added via tongue weights.

[CWSWine]

Its hard to explain the relationship between the GVWR, GCWR, and Towing Capacity but this video made clear to me but it for trucks and tow behinds but it is the same principle.


Matching Trucks to Trailers

[MisterT]

I would say there was a misprint of the first word, which should read 'MAXIMUM' since it is alluding to the 'bare' maximum Towable weight IF the owner does NOT weigh their fully loaded RV, choosing to use the 'base' GCWR minus the GVWR, since this is the 'maximum' of the both numbers.

Since the owner could decide to drive the RV 'dry', or close to it, the manufacturer's assumption of the GVWR, fully loaded, would then be MORE than what the owner is actually driving, therefore the 'additional' left-over weight between the two is what can be added to the 'maximum' towable rate. See? Fun. ; ) *see examples below

or they could have chosen the term 'Minimum Maximum towing weight'... but that would be even more confusing!



*GVWR 30,000lbs (assumed fully loaded)
GCWR 35,000lbs (chassis maximum loaded and towable weights combined)
Towable 'Maximum' = 5,000lbs (the difference between the two, as described by the owner's manual definition from above)

examples:
A) GVWR 32,000lbs** (owner has loaded the RV with people, fuel, water, etc)
then the REAL Towable Maximum = 3,000lbs

B) GVWR 29,000lbs** (owner is single, no pets, little fuel, water, and stuff!)
then the REAL Towable Maximum = 6,000lbs (but only if the hitch is rated this high)


**here's the catch: the ONLY way to know this is to 'weigh' your coach!

[70ChevelleSS]

GVWR is the maximum weight the chassis can carry. Let's say a MH with a 22,000 lbs. chassis weighs 19,000 lbs. as delivered from the factory. This means you can carry 3,000 lbs. of cargo. You also have to consider fuel and water, etc.

That 22,000 lbs. chassis may have a GCWR of 25,000 lbs. So if you're loaded with 3,000 lbs. of cargo, fuel, propane, water etc. you've hit the GVWR. So that leaves 3,000 lbs. of towing capacity 22,000 + 3,000 = 25,000, the GCWR.

Now if you only add 2,000 lbs. to the unloaded chassis that gives you an extra 1,000 lbs. you can tow, still adds up to 25,000 lbs.

GVWR is the max weight the chassis can carry. The weight is split between front and rear axle, each weight is different.

GCWR is the max weight the engine and drive train is designed to pull down the road.

Now, if I explained that properly there are other things to consider.

Flat towing a vehicle adds very little vertical weight to the hitch so it doesn't really affect the GVWR, only the GCWR. Tow dollies are similar. Now an actual trailer will add vertical weight to the hitch so it affects GVWR, rear axle weight rating and GCWR.

So if you understand all this you also need to know the ratings of your hitch. It will have a max towing capacity, and a max tongue weight.

Sure hope I didn't confuse you even more.

[l1v3fr33ord1]

The HR statement is correct as written. If the coach is loaded such that its weight is equal to GVWR, then the towable weight is at its minimum, that is, GCWR - GVWR.

If you load the coach below the GVWR (which correctly-termed is the "GVW," Gross Vehicle Weight), the the HR statement is saying the towable weight is GCWR - GVW. As others have pointed out, GVW is only correctly measured on a scale.

That said, there are other potential limits on towable weight:

1) the hitch horizontal tow rating
2) the hitch tongue weight rating (if talking trailers)
3) the axle weight ratings (if talking trailers)
4) the maximum trailer weight (rarely does a manufacturer specify this)

[MisterT]

excellent correction Mark, I like the GVW versus the 'normal' misstated GVWR because that's alluding to a stated weight, but the GVW is the 'weighed' weight! See!

[paddler1954]

I skimmed the other answers very quickly so I might be providing duplicate information. The reason HR GCWR is so confusing is because the Freightline chassis can support the total GCWR. BUT the Allison 2500 transmission is the limiting factor. It can only handle slightly more than the GWR of the HR about 33000 lbs I think. Hope that helps explain the slight of hand Fleetwood pulls on these specifications.

[Vacay Wheels]

This is where I think it's good to remove CCC from calculations and use UVW (unladen vehicle weight).

Then just make sure that

UVW + you + your stuff < GVWR

UVW + you + your stuff + your car < GCWR

[Crasher]

"†† Minimum Towable Load is the available weight, up to GCWR, when the coach is fully loaded to maximum GVWR. However, if the coach is loaded to something less than maximum GVWR, that extra available weight can be added to your Towable Load. For example, if your coach is loaded to 1000lbs less than maximum GVWR, your Towable Load increases accordingly."

I understand what they are trying to say, but it is confusing in the way they use the word "minimum". It would be very clear if they said that when the coach is at it GVWR, the "Maximum" towable load is 3000#. However, if the coach is loaded to 1000# less than the GVWR, the "Maximum" towable load would increase by 1000# to 4000#. Doesn't this make the original statement more clear and understandable??

[gstrohl]

The original statement as written is as clear as mud . However with each explanation came slivers of clarity. Thank you everyone!

I now understand why on occasion I have seen RVs with a tow hitch rated more than the stated tow capacity. For instance, a motorhome with GVWR of 26,000lbs, GCWR of 31,000lbs yet a tow hitch rated 7,000lbs. Generally 5,000lbs would be the tow limit if GVWR is at its maximum (26,000). But 7,000 is allowed should the motorhome weigh 2,000lbs less than the GVWR.

I appreciate everyone's time and effort spent with the explanations. Gerry

[l1v3fr33ord1]

Gerry-

Here are some actual numbers to illustrate. For our coach:

GCWR = 25,500 pounds
GVWR = 20,500 pounds
GAWR (front axle) = 7,500 pounds
GAWR (rear axle) = 13,500 pounds
Calculated combined axle weight ratings = 7,500 + 13,500 = 21,000 pounds
Note that this is 500 pounds more than the GVWR
UVW = 16,975 pounds
Calculated maximum weight of contents = 20,500 - 16,975 = 3,525 pounds
"Contents" means everything but the coach

Last year we had our loaded coach four-corner weighed for the first time. It had a "typical" load of contents. Side-to-side balance was almost spot-on. The results:

Front axle: 6,350 pounds
Calculated amount front under axle rating = 7,500 - 6,350 = 1,150 pounds
Rear axle: 13,350 pounds
Calculated amount under rear axle rating = 13,500 - 13,350 = 150 pounds
Calculated total weight of coach as loaded = 6,350 + 13,350 = 19,700 pounds
Calculated weight of contents = 19,700 - 16,975 = 2,725 pounds
Calculated amount under GVWR = 20,500 - 19,700 = 800 pounds

As you can see, we could add 800 pounds of contents to our coach, as long as 650 pounds went on the front axle and 150 on the rear axle.

A lot of the rear axle weight is fluids (gasoline, fresh, black and grey water). I have since shifted some stored items forward in the coach, and removed other lesser-used items, in an effort to reduce non-fluid weight on the rear axle and better balance side-to-side.

Our coach's hitch is rated 5,000 pounds (flat-tow) and GCWR - GVWR = 5,000 pounds, so we can flat-tow 5,000 pounds and be within the ratings. Our toad weighs under 3,000 pounds. I have not looked to see what the tongue-weight rating is for the hitch. That would be important if I towed a trailer. I'd have to keep rear axle loading in mind with any significant tongue weight, too.

[momdoc]

Bottom line is to load your coach as you would when you travel (water, gas, household goods, clothes, storage bays full of your stuff and an so on) then go to your local truck scales and weigh the coach (front and rear axles to make sure you are "weighted" correctly). Then the difference what you can tow.