Towing capability math equation

Need more info. "X" trailer could mean just about anything. I'm assuming you're referring to either a travel trailer or a fifth wheel trailer. Correct?

Also need more info on the tow vehicle....are your talking about 1/2 pickups or something larger.

There just can't be a "simple" (equation) calculation that will fit all possibilities. Just too damn many variables.

Ron

There are so many variables associated with TV’s and TT’s it would take a very sophisticated spreadsheet to make a “simple” calculation. That said, I tried one of the spreadsheets mbutts suggested and it worked pretty well. But I know all my weights, including the TT. Most newbies shopping for a TT are not going to have a clue what their TV ratings are or what a potential TT might weigh loaded, or the loaded tw. But I guess they could make an educated guess based on the TT GVW and 15% for the tw. If there’s an error it will be in their favor.

My manual says I can pull about an 8000# TT. But the tw would be far over my remaining payload, common with a ½ ton. In fact, I’m pulling 65% of my GCVWR and 67% of my payload. Probably why mountain grades aren’t an issue and my gas mileage is good. Knowing all my ratings and weights I could have made the calculation manually every bit as easily as the spreadsheet. But the spreadsheet could be useful if one knew their TV ratings and used gross numbers for the TT. Then they could see the results of an input and tweak the TT numbers until they get weights they’re happy with.

And don't forget to add in your intended use.
If you're doing a few weekend trips a year in the flatlands you'll be able to get by with less truck, to a point, than if you're full timing in the Rocky Mtns and running 15k miles a year.

So not really a formula other than the tow vehicles weight ratings.
I'd describe your intended use and then sift thru the advice you get.

PUCampin wrote:
It depends on what you are towing with. A 1/2 ton will run out of payload before anything else, 3/4 and up not as much.

If your TV is newer that 2006 it will have a tread act sticker listing the maximum allowable passengers and cargo. This is for your vehicle as it left the factory. Subtract dealer options, people and stuff, and this is what you have left for tongue weight. Divide that by 0.14 to get a fully loaded trailer weight, then take away 1000lbs for water and stuff to get a dry weight.

Quick example that works well for 1/2 ton

My 1/2 ton Expedition

Max Payload = 1672lbs
No add ons = 0lbs
Family = 665lbs
Carseats = 75lbs
Stuff = 75lbs

1672-665-75-75 = 857lbs for tongue weight

857 / 0.14 = 6121lbs full loaded trailer = 5000-5500 dry

Far cry from my max tow rating of 8900lbs huh?

5000-5500lbs dry seems to be a sweet spot for most 1/2 ton SUV and a family of 4, it will pretty much keep all numbers in line. 7-8 people will reduce that.

Good hunting!

Very nice! I would only add that if you only have 2 people it might seem that you can push that fully loaded weight up a bit because you're not eating up that payload with kids and car seats. But then the limiting factor could be the tongue weight. The highest I've seen on GM 1/2 tons is 1200# and that's on the 2014s. Typically its 1000#.

It depends on what you are towing with. A 1/2 ton will run out of payload before anything else, 3/4 and up not as much.

If your TV is newer that 2006 it will have a tread act sticker listing the maximum allowable passengers and cargo. This is for your vehicle as it left the factory. Subtract dealer options, people and stuff, and this is what you have left for tongue weight. Divide that by 0.14 to get a fully loaded trailer weight, then take away 1000lbs for water and stuff to get a dry weight.

Quick example that works well for 1/2 ton

My 1/2 ton Expedition

Max Payload = 1672lbs
No add ons = 0lbs
Family = 665lbs
Carseats = 75lbs
Stuff = 75lbs

1672-665-75-75 = 857lbs for tongue weight

857 / 0.14 = 6121lbs full loaded trailer = 5000-5500 dry

Far cry from my max tow rating of 8900lbs huh?

5000-5500lbs dry seems to be a sweet spot for most 1/2 ton SUV and a family of 4, it will pretty much keep all numbers in line. 7-8 people will reduce that.

Good hunting!

This link has a link in it that has a spreadsheet.

It's easy, stay under the maximum ratings of the following, Gross Vehicle Weight Rating (GVWR) of the tow vehicle (weight of the combined, vehicle actual curb weight and weight on the vehicle including actual tongue weight), The Rear and Front Axle Weight Ratings (RAWR, FAWR) which is the actual weight on the axles with trailer hooked up, Tire ratings as inscribed on the actual tires at maximum PSI (actual weight resting on the tires when hooked up to trailer), The Maximum Tongue Weight (TW) as inscribed on the Tow Vehicles Receiver, the Maximum Trailer Weight for vehicle and receiver sometimes referred to as the Tow Rating and some folks also include the maximum Gross Combined Weight Rating (GCWR) which is the total weight of vehicle and trailer together. Stay under all 8 ratings and you are good to go.

Well, staying out of the tounge weight subject because you are not asking that, keep it simple if your truck is rated to tow 7000 pounds then dont tow more than that. The only other thing is to make sure you don't exceed the GCWR, the combined weight of both trailer and the car or truck towing.

Happy trails.

For RVing? Not really. It depends on what rating of the vehicle someone hits first. It could be GCWR/Tow rating, rear axle, receiver, GVWR.