rk05, Yes, you are thinking correctly. Its an add up and take away equation. Your vehicles weight is not what it says on the title , it is with EVERYTHING you carry inside or on top of your TV. Hopefully, your vehicle has a factory tow package.
If not, you might want to think about some kind of tent. :B
On the serious side , there is a weight decal on your drivers door jam or possibly inside the glove compartment on a sticker that shows approx., payload.
I understand your situation and it's often more difficult to match the TV to a TT if you already have the TV.
Already having the TV , you have less selection for a suitable floor plan to compliment your TV weight restrictions.
You must think of it as 2 individual vehicles with each having their own suspensions that has ratings and restrictions.
When you balance each one, they compliment one another as a towed unit, while being joined by a weight distributing hitch of proportional size. ( don't forget, the WD hitch also has weight, maybe 100# , comes off the payload and it's considered part of the hitch weight equation as far as i know. One of our engineer members would know better than me )
In order for any of us to acquire a real true payload weight is to have your vehicle weighed at a certified scale . Then you will know exactly where you stand with the amount of stuff you carry. It's very different for each of us. ('I bring one bag, my DW brings 7 bags and 4 for the dog, at this point i'm pushing being overloaded and she is still carrying out more stuff' )
Load up your TV as if you were going on a trip. Everything that's inside the vehicle is weight. People,tools, dogs, coolers, kids, computers etc. This is the payload that many people need to watch because many of us use up our payload before using up our towing capacity.
Re tires : "P" rated tires that offer a smooth ride where the carrying capacity would be less than an LT tire of equal size. You want a more stiff sidewall (LT tire) when towing a TT. It helps a lot with crosswinds and bow waves from overtaking trucks and buses. Remember most of us tow at or below 65mph due to restricted ST tire speed ratings and common sense. Sometimes bigger professional drivers pass us by like we are standing still. Just remember #1 rule, You as well as your TV need to be in control , not the other way around.
I would look around for a smaller simple floor plan until you are in a better position, then upgrade the entire package if the Rv lifestyle fits your family . As the family grows, your floor plan needs may change.
Good luck and stay safe,
b n d .
