Since my TH is such a fat pig, Ive spent a lot of time at the scales with my TH, loaded, unloaded, partial loaded, etc... trying to get my TW as low as possible. A guy at my RV storage has a Sherline TW scale that works great.
My empty TW is almost twice the weight of what it was advertised as. The gvw is not quite that bad but still WAY off.
With my 1500lb turbo RZR pulled in front first,with the rear wheels as far back on the beaver-tail as possible, my tongue weight reduces 50-80lbs with a fully loaded TH. This is with a 13,000+gvw triple axles bumper pull.
1 of my 3, 50 gal water tanks are more or less over the axles,2 just in front of them. They add big time to my TW... My 50gal grey and black tanks are in front of the axles. My 40 + 20 gal fuel tanks are in the very back and seem to do little either full or empty to the TW. The 3 propane tanks on the front of the TH seems to add weight directly to the tongue.
So to answer your question, on a heavy triple axle TH, weight behind the axle doesn't do much to lower the TW. But loading weight in front of the axles(water tanks) increases TW a very lot.
jmo
