Increasing Tongue Weight on Nissan NV3500 (or in general)

Ron Gratz wrote:
It might just be coincidence, but ---

The SAE J2807 test standard defines procedures and requirements to determine Gross Combination Weight Rating (GCWR) and calculate corresponding Trailer Weight Rating (TWR) for any tow-vehicle.

The testing protocol specifies:

4.4.2.4 Trailer Tongue Weight (Conventional Trailers)

Ballast should be applied to the trailer in a distributed manner such that the trailer tongue weight is 10% of total trailer weight ±0.5%, or ±5 kg (11 lb), whichever is greater, at a nominally level attitude as described in 4.4.2.8. This is intended to provide a nominal longitudinal center of gravity (cg) position of the ballasted trailer that is 10% (of the effective tongue length) forward of the trailer axle(s) centerline.

Therefore, it seems that a manufacturer who is claiming compliance with J2807 cannot specify an allowable tongue weight which exceeds 10% of the "Trailer Weight Rating" -- unless they do their testing at a trailer tongue weight which is greater than 10% of total trailer weight.

For several years, Ford has been specifying "Max. Tongue Weight" to be 10% of "Max. Trailer Capacity".
An example is in the chart at the bottom of page 25 of the 14RV & TRAILER TOWING GUIDE.

Jeep also defines "Max. Trailer Tongue Wt." as 10% of the "Max. Gross Trailer Wt."

IMO, it is possible that those manufacturers who specify maximum tongue weight as 10% of maximum trailer weight have not established a physical basis for limiting the tongue weight.
Rather, it seems that their 10% tongue weight limit simply might be a weight used in a test procedure which establishes a value Trailer Weight Rating.
I guess it could be possible that their vehicles are fitted with receivers which are certified for a combined load consisting of a longitudinal force equal to the max trailer weight and a vertical force equal to the max tongue weight.

Really good insight. I've talked to some other folks via PM and other forums who believe that the weight limit is without a WD hitch and that a WD hitch effectively increases it; though no one knows by exactly how much.

Since this is the same hitch they're putting on the cargo van and they list the cargo van at a 950 lb. tongue, I'm going to assume that the hitch is rated for at least this much as long as I get all other axles/ratios/gross weights in line. That will be more than enough for what we want to pull (an ultra-light bunk house).

Fred