Here's what I think the calculator is doing:
- You enter the trailer's GVWR. It's calculating the pin weight at 25% (e.g. 15,000 x .25 = ,750).
- It is then adding the rear axle weight (2,800) plus the pin weight (calculated at 3,750) (this gives you 6,550).
- It is then comparing that against the GAWR (gross axle weight rating) and telling you if you are under or over (e.g. 6,550 > 6,100):
- if over, it's a NO GO
- if under, it's a GO
The problem that I have with calculators such as this is that they're making assumptions. For instance, I think 25% of the loaded weight is excessive for this 365RL. If you take the dry hitch weight / unloaded vehicle weight, you get 16.2%. You can see those numbers here:
Palomino RV - Manufacturer of Quaility RVs since 1968
Dry Hitch Weight: 1,910 lbs.
Unloaded Vehicle Weight: 11,766 lbs.
Percentage: 1,910 / 11,766 = 16.2%
It's realistic that the percentages change by 2% to 5% as you load up the camper. This is primarily because most of your big storage areas are ahead of the camper's axles (front basement is the biggest, bedroom storage, bathroom storage and even likely a portion of the kitchen storage). A more realistic actual loaded pin weight for the 365RL is 18%-20% of the camper's total loaded weight.
The next issue that I have is using the GVWR for calculations. This camper has an advertised dry weight of 11,766 pounds and a GVWR of 15,910 pounds. That means it has a maximum cargo carrying capacity of over 4,000 pounds. I'm known for packing heavy- everything, doubles of everything and the kitchen sink; we're somewhere between 2,000 and 3,000 pounds from the advertised dry weight.
Only you can figure out what your realistic actual weights are. Given a camper of that size, the first 500-800 pounds are likely going to be taken up by options (solid surface counter tops, extra A/C, slide toppers x4, central vac, air pin box, etc, etc.). Then, you add your stuff. And finally, whatever water you may normally carry- add that at 8 lbs. per gallon (fresh water, hot water, gray tanks (2), black tank).
So, putting this all together:
- Loaded pin weight percentage: 19.4%
- Loaded weight: 14,266 lbs.
- Real life pin weight: 2,739 lbs.
(See how I got that with this calculator
Now, the next thing that you'll want to figure out is which truck ratings matter to you. From this app, it's only looking at the axle weight rating. There is also the gross vehicle weight rating (GVWR) of the truck and the tire load capacities. Some people have no problem exceeding GVWR as long as they're under the axle weight rating and tire load capacities. Others (like me) prefer to be within all of their truck's ratings).
In my opinion, usually when people are pulling big campers with 3/4-ton trucks, they're exceeding GVWR.