whats the correct formula for tow weight

[lee cole]

Looking at the Jayco Jay Flight 28bhs (4890 dry weight) and the Coachman Apex 288bhs (4842 dry weight). Would these be to big for a Ford F-150 rated 6200 LBs towing capacity. The 3 different salesman I have talked to all have said I would be fine. First salesman said stay 500lbs below max, second said 1000lbs below max, and the third said do stay around 75% of max. I know that having your truck set up correctly to pull the TT you select is important. Help

[Knightab]

Sounds like you will be ok. There will be additional weight with personal stuff and water and propane on board but I don't think you will be overloaded. Your gross combined weight tells a better story if you get a chance to get it weighed.

[paz]

Hi Lee,

You need to look at the GVWR of the trailer, not the dry weight. The dry weight listed on a manufacturers website or brochure is frequently calculated, not an actual weight, and is usually on the optimistic side. It won't include any options or any water or cargo. The actual weight will vary depending on how you load the trailer, but the GVWR is supposed to be the maximum weight the trailer and all cargo.

The rule of thumb is to allow some reserve by not exceeding 75 or 80% of the towing capacity of the tow vehicle. Lots of people don't do that.

[lee cole]

Just to be straight, you should not exceed 75% or 80% of the dry weight or the GVWR

[scbwr]

Originally Posted by lee cole

Just to be straight, you should not exceed 75% or 80% of the dry weight or the GVWR

I agree with this. See my reply on the other thread you started.

[wandering1]

Read the towing specs for your truck from ford. Forget about what the salesman says and the door frame sticker says.

[Loraura]

Check the door stickers for max cargo capacity or payload, it may reference max lbs for people and items inside truck. This is usually the limiting factor on half ton pickups.

Your payload, or CC, consists of you, gas in the truck, any people, food, luggage, dogs, ice chests, etc, plus the weight distribution hitch (100 lbs or so) and all the tongue weight that the trailer puts on the hitch.

Some brands include a full tank of gas ans 1 150 lb driver, some do not.

1/2 ton payloads vary some by brand and trim level. The higher trim level trucks eat up some of their own payload in features and leather.

So to really know, check the sticker that references payload or max carry capacity.

You should be fine with a TT with a dry weight under 5k, but it's always best to check the stickers for your individual truck and do the math.

If you've added some after market items like roll bars, cattle guards, steps, etc, those will also subtract from your payload.


You will want to calculate 12-15% of the total wet and loaded TT weight and add THAT to the payload as the tongue weight. The advertised tongue weights are of a dry trailer, usually with no battery or propane on board, and sometimes without any options included in the TT weight like the AC, fridge, oven, etc.

[SmokeyWren]

Originally Posted by lee cole

whats the correct formula for tow weight

There is no such thing as a good formula for estimating the max trailer weight of a tandem-axle travel trailer (TT). My tow vehicle, for example, has a tow rating of 8,400 pounds, but I'm overloaded with my TT that grosses 4,870 when wet and loaded on the road. That's 58% of Ford's advertised tow rating.

My previous tow vehicle was an F-250 diesel with tow rating over 13,000 pounds. But it was overloaded with my small 5er that grossed only 8,000 pounds when wet and loaded on the road. That's 61.5% of Ford's tow rating.

But I'm not going to suggest that 58% or 61.5% is a good formula for others to use.

Instead of picking a number out of the air, you need to know the weight of YOUR tow vehicle when wet and loaded for the road before you tie onto any trailer. Wet means a full tank of gas, and loaded means with all the people and other things that will be in the tow vehicle when towing, including the weight-distributing hitch, campfire wood, tools, and options such as a bed liner.

Subtract the weight of your wet and loaded tow vehicle from the GVWR of that tow vehicle and the answer is the maximum tongue weight of any TT you can tow without being overloaded.

(The maximum tongue weight is also called the available payload capacity of your tow vehicle. There is probably a payload capacity number on the doorframe of your tow vehicle, but no, you cannot use that number either, because it is not the available unused payload capacity of your wet and loaded tow vehicle. So you must weigh the wet and loaded towvehicle to determine the real-world payload capacity available for tongue weight.).

Divide that maximum tongue weight by 0.125 and the answer is the maximum GVWR of any TT you want to consider. Or if you want to be conservative and almost guarantee you won't be overloaded with a TT that is not overloaded, then divide the maximum tongue weight by 0.15 instead of 0.125. Tongue weight of an "average" wet and loaded TT is about 12.5%, but max tongue weight of many TTs is about 15% of wet and loaded trailer weight.

And don't try to guess at the wet and loaded trailer weight. Use the GVWR of the trailer as the probable max trailer weight you'll have in the middle of your third RV trip.

Sorry to bust your fantasy of a simple formula to determine the max weight of any TT you might want to tow. But the simple facts of life is that there is no such formula.

[Franka548]

X2 on what SmokeyWren said.
Frank

[tuffr2]

A relatively safe formula is 25% to 30% as long as 100% of the 30% is not on the truck.