Help with hitch / tongue weight

Ron Gratz wrote:
"TONGUE WEIGHT", "HITCH LOAD", "RECEIVER LOAD" CONFUSION -- TOO MANY "DEFINITIONS"

This thread, "Help with hitch / tongue weight", has been plagued with a failure to communicate a clear understanding of what key terms, such as "tongue weight" actually mean.
Perhaps we could have more meaningful (and more civil) discussions of "hitch weight" and "tongue weight" and other technical terms if we had a single and agreed definition for each of them.

A good example of possible sources of such confusion can be found in Determining Trailer Tongue Weight.
The presentation begins with:
"In order to select the correct components to safely tow your trailer, you need to know its tongue weight. This is the weight that the fully loaded trailer exerts downward on the hitch ball of the tow vehicle. If you don't know the tongue weight of your trailer, there are several different ways you can determine it."

They then show a diagram which defines "tongue weight" as being the difference between tow vehicle GVW when hitched with WD applied MINUS the tow vehicle GVW when loaded with trailer not attached.
This is incorrect because the TV's hitched GVW must be measured when WD is NOT applied.
Finally, they introduce a new relationship, A - B + C = "Tongue Weight for Weight Distribution System".

To add to the confusion, we also have the statement from a Cequent sales catalog:

"SELECTING THE RIGHT WEIGHT DISTRIBUTION SYSTEM
The hitch weight formula for determining the load which the hitch must carry:
HITCH WEIGHT* = TONGUE WEIGHT + VEHICLE CARGO LOAD BEHIND REAR AXLE
Tongue weight includes the trailer tongue weight with full gas, water and waste systems and everything packed inside the trailer.
Vehicle cargo includes all materials carried in your tow vehicle, such as boat motors, gas cans, tools, etc."

This Cequent catalog instruction seems to define "HITCH WEIGHT" similar to the way etrailer defines "Tongue Weight for Weight Distribution System".
This is incorrect usage of "hitch weight" or "hitch load",
Hitch Load does not include the weight of vehicle cargo load behind the tow vehicle's rear axle.

Perhaps it also would help to have a single agreed definition for "hitch weight" or preferably "hitch load".
And while we're at it, let's have a proper definition for "receiver load".

I believe the following definitions would help to eliminate much of the confusion which has plagued this thread:

Tongue Weight The load exerted by the coupler on the ball with the trailer loaded and level, and with no load distribution applied.

Hitch Load The net load exerted on the hitch head by the coupler and WD bars.
(Note: Hitch Load is equal to Tongue Weight with no load distribution applied. Hitch Load is equal to Tongue Weight minus load transferred to TT's axles when load distribution is applied.)

Receiver Load The load exerted on the receiver by the hitch.
(Note: Receiver Load is equal to Hitch Weight plus the weight of the WDH.)

Ron

Won't try and quibble over some of the definitions since IMO there is not much confusion if one understands what is trying to be conveyed. Several general comments:

1. You describe the Cequent catalog as a "SALES CATALOG" which IMO does the same thing you are objecting to in the use of the various tongue wt., hitch wt. etc. terms. The item is actually a "PRODUCT CATALOG" which has NO PRICES, but has things like matching say a hitch and or receiver to a specfic model tow vehicle (i.e. application guides to model numbers, etc.), sizing various components one being the WDH systems of which is directly germane to this discussion. Thus to me it's not selling anything and as such NOT A MARKETING TOOL, but it's sole purpose is to assist one in selecting and sizing the correct item based on needs w/o regard to price.

2. If one takes a too narrow view of tongue wt. and doesn't understand what it really means then I guess one could get confused and that is one thing I tried in one of my very first posts in this thread to acknowledge and tried to differentiate what is normally classified as tongue wt. as being "dead tongue wt" like is measured by a Sherline scale. Issue is things like a receivers only shows tongue wt. specs in a weight carrying and in a weight distribution mode which in one the tongue wt. does only equal what I call "dead tongue wt." (i.e. in the WC mode) whereas tongue wt. IMO (this might be subject to some disagreement, but I see no way to prove one position or the other) equals the "dead tongue wt." plus this cargo added behind the rear TV axle and which CEQUENT has called "HITCH WEIGHT" for the reciever tongue wt (i.e. in the WDH mode). Thus simply trying to create some universal tongue wt. definition will run afoul of how equip is labeled now and will probably never change. Receivers will still call it tongue wt. and WDH systems will still mostly still call it tongue wt. I think a better solution is to simply explain as I thought as I have tried in this thread to explain what each is composed of in the context in which it's used. Thus tongue wt. means different things such as.

1. For a trailer by itself it is the weight of the ball coupler when placed on a device such as a Sherline scale.

2. For payload calculations it is the same as 1 above that is added to the TV weight in a weight carrying configuration.

3. For a trailer and TV combo with a WDH then it is 1 above PLUS any cargo added to the rear of the TV rear axle that was not present when the WDH was adjusted and setup.

4. For payload calculations for a trailer and TV combo with a WDH it is 1 plus any cargo added after the WDH has been adjusted and setup MINUS the increase in the load on the TT axles over it's base line trailer only wt. This means as is generally know that the full amount of the "dead tongue wt" does not all show up on the GW of the TV, but also any cargo added aft of the rear axle a portion of that that shows up as additional wt. on the TT axles is not then carried by the TV. This is a real touchy/feelee area and is probably in 99.99 percent of the cases this reduction in the amount of the added cargo that is actually carried by the TV can be ignored.

I appreciate what you are trying to do, but I don't see it every getting any sort of universal acceptance and in the end I feel the best solution is to educate folks that tongue wt. is not necessarily a fixed number which in reality it isn't since it can vary as a function of trailer loading, but can also vary as a function of TV loading when in a WDH configuration. This is IMO the most consistent method of treating this tongue wt. so it's properly accounted for and used w/o mucking around with individual equipment descriptions.

One final comment is your statment that the etrailer method of determining tongue wt from scale measurements was incorrect. However if you look at the diagrams there is what appears to be a WDH system on the trailer tongue, but it's not in play since when the trailer is unhooked the WDH bars are still on the trailer. I have a feeling none of these wts. were for any WDH being actually hooked up during the various weigh ins. Someone drew them in on the trailer, but all these wt. were in a WC configuration only w/o the WDH disconnected and as such were in fact CORRECT. I do agree they should not have even been shown since they could be a source of confusion.

Larry