Help with the towing math

RobWNY wrote:
I wasn't aware that the wheels on Heartland trailers were closer to the hitch than on most trailers. That does make sense why the tongue weight advertised would be lower though. Interestingly, earlier today I was reading about manufacturers towing limits. It seems there isn't any real standard that's adhered to. The SAE J2807 truck towing standard is meant to be able to compare apples to apples with different trucks towing and cargo limits but Gm, Ford and Dodge don't adhere to the standard so it's more of a PR thing to "one-up" the competitor. They all say they will be adhering to the standard but as of now they don't. The numbers they list aren't really accurate. They could very well be inflated. So if trailer specs aren't accurate and tow vehicle specs aren't accurate, how does anyone use formulas to know if their tow vehicle is within the limits? Just because a truck has the power to tow something, doesn't mean it's safe to do so. I think there's a whole lot more that has to be known. For instance, you could have heavy duty shocks and springs, plenty of engine, really sturdy frame and brakes and rotors that aren't big enough to handle the weight they have to stop. That would make the tow vehicle unsafe. I can see where there are thousands of people with all kinds of trailers that think their tow vehicle is safe and it really isn't. Scary thought!

The TOWING RATING NUMBERS are suspect but the CARGO RATINGS IS DEAD ON.

The CARGO ratings CAN be used to determine just how much can be towed since it is the limit of what your vehicle can carry, period.

in your case, you have 1400 lbs cargo available, subtract fuel and passenger weight and you have the MAX tongue weight as "cargo".

So as an example, 300 lbs in passengers minus 240 lbs of fuel minus 100 lbs for WD gives you a max of 760 lbs of leftover cargo for your trailer.

Working backwards knowing that 10% (760 lbs TW)is the min target weight we can say that the max trailer weight is 7,600 lbs.

But we REALLY do not want to tow at 10% since that is the beginning point for stability..

So using 15% (760 lbs TW) would give you a MAX of just UNDER 5,000 lbs MAX trailer weight..

It is this problem above which inflates the tow ratings.. The manufactures INTENTIONALLY USE 10% tongue weight for advertising what the vehicle can tow.

Folks hear that bigger inflated unrealistic number and buy trailers which tend to be at or above what they SHOULD be hauling. Then they blame the manufacturers.. When in reality the OWNER ultimately is to blame since they did not do any REAL homework to find out REALISTICALLY what the max is..

It is for the reasons above I STILL say that folks SHOULD IGNORE THE DRY WEIGHTS of the trailer and instead shop by the max GVWR of the trailer. Doing this completely eliminates these kinds of mistakes from happening..

For example RobWNY, if you take 9000 lbs GVWR of your trailer 10% is 900 lbs and 15% is 1,350 lbs you can CLEARLY see that your trailer CAN EASILY EXCEED your available cargo of your vehicle. No guessing, no mistakes.

Realistically you should have bought a trailer with max GVWR of 7,000 lbs which allows you some wiggle room for passenger and fuel plus maybe even a stick or two of fire wood in you truck bed.

See just how easy that method is?

While there folks here which insist on using dry weights and adding up every piece of clothing, food and other gear it just makes MORE work than needed. But they do it that way so they can justify towing a bigger heavier trailer than they should be...