Reaching out for help with tow numbers

[lanedawg]

Maybe someone on here can help me with the numbers. I own a 2016 F-250 , 6.2 L/ GAS,4-wd, crew cab, SRW Lariat, short bed, with 3.73 rear end. Using a 16K Pullrite slider hitch. I have 20" Toya A/T LT 275 / 65 R20 Steel belted radial tires. Here are the numbers from Ford.
( TRUCK )
GVWR: 10,000
GCWR: 19,000
VEH. CURB WT: 6828
FRONT CURB WT: 3945
REAR CURB WT: 2883
FRONT GAWR: 4800
REAR GAWR: 6100
PAYLOAD: 3100
FRONT AXLE CAP: 6000
REAR AXLE CAP: 6200
TOWING CAP: 12,100

I'm looking at purchasing following: 2018 Jayco Eagle HT 30.5 MBOK/ 5th
wheel trailer.

Specs on this RV:
Unloaded wt: 9635
unloaded pin wt: 1795
GVWR: 11950
Cargo Cap: 2315

additional info: Pullrite hitch at 250#, Humans: ( adults & kids ) 700#
just want to know can I safely tow this particular 5th wheel safely

 

[weighit]

I look at a few things first. You can't go by the unloaded weights as nobody ever travels empty, look at the gross weight numbers. Your rear axle of the truck will carry 6100 lbs max. The trailer weight max is 11950 times 20% for an average pin weight equalls 2,390 lbs. You need to run the truck over the scales to see what the rear axle is already carrying without the trailer you should see numbers from 2,900 to maybe 3,400lbs with the hitch and people, fuel and stuff. Subtract the starting weight from the gross allowable so 6100-3400= 2,700lbs and the possible trailer pin of 2,390 = around 300 lbs to the good. That is if all the estimated numbers are close to accurate. Make sure the tire load ratings fall into the safe zone, how much each tire can support with the correct air pressure. Looks like your close but doable. You might be over one or more of the trucks gross numbers, and if so then you get to decide how you want to proceed. This will give you a start to understand the weights and measures in towing a trailer.

 

[lanedawg]

Thank you Stripit. Gives me something to think about. Maybe I go to a lighter RV

 

[weighit]

Before you change your mind just really check the numbers and see exactly where you fall. I didn't understand you actually ran over the scales. Was that with the hitch, full fuel and family in the truck to get those numbers?

 

[lanedawg]

yes.... those are scale numbers for the truck only, I don't own the RV. No way of knowing those numbers. I just have a hard time with the math, and was hoping someone could steer me or give me a formula. Since this will affect my family, just wanted to make sure I had enough truck to not only pull this particular 5th wheel, but have the ability to stop it also. By the way I have decided to add airbags on my truck. Don't like the look of other 250's towing and they all seem to squat. oh, and that was family , full fuel and hitch

 

[wingnut60]

lanedawg,
In my opinion only--you can push the axle limits, the gross limit, the gross combined limit, but NOT the tire capacity limit. Air bags only prevent rear sag, but do not raise the axle/tire capacity.
As Stripit said, it doable but close. A similar 350 would be a better setup for the numbers, but mostly the same truck.

 

[lanedawg]

Da Wife ( DW )

I thought I would run the numbers out there and get a feel for what others thought. I kind of suspected I would be pushing it pretty tight. I just broke the news to the DW. She asked what are were we going to do. ( smile ) I said guess I'll buy a bigger truck. NOT ! Her excuse and I quote " Oh hell no, you have had two new trucks in three years, and I still have a 10 yr old car I'm having to drive. Guess smaller is better, RV that is. As much as I would like a F350 , think cutting back on weight would be a better deal for me. I'll just have to choose another Eagle HT 5th with a little less GVWR. But before I do that, will be walking DW through it. Never know she might change her mind, right ?

 

[lanedawg]

Wingnut...is there anyway to send me the formula you use to determine the numbers as I have yet to get all this straight in my head. That way I'll have it to use on the up coming purchase. I thank you very much and all of the people who have tried to help me.

 

[weighit]

How I used to do it was to weigh the truck loaded ready to travel, weigh each axle so you know front and rear axle weights. That is the base line. Then having those numbers compare those to the truck Gross weigh limit, and axle limits, also inspect the sidewall of the tires to see what that max load carrying is. Then most folks use 20% of the gross weigh limit of the trailer as the "possible" pin weight that will go to the truck. That 20% is only a guess as some are much more, others less, but use that as a refference point. So if you find a 15,000GVW trailer, you can guess 3,000lbs of pin weight going into the bed of the truck. On the trucks sticker you will see GVWR of the axles, but if you add those up you will see it doesn't equal the GVWR of the truck, as it will be less than the sum of the axles. Now comes the fun part, which number do you feel safe being over. For me not the tires, but the rear axle "could" be at or over and still be under the tires max load. I used to find most of the 250/2500 series trucks were over some rated number when hauling larger trailers. That didn't mean that once you go over a number on the truck, it would fail, otherwise you would see hundreds of pickup trucks scattered along the highways. But overloading is not something I would recommend. They place limits for safety and durability. Sometimes these numbers get real confusing and takes a while to understand.

 

[wingnut60]

Gross Vehicle Weight Rating (GVWR) as listed on the door tag LESS the ACTUAL weight of the truck as set up to travel/tow = weight available for the trailer to put on the truck.
Example: 10000 GVWR - 6800 actual travel weight = 3200 left for trailer pin weight.
You can't get this correct figure until you weigh your truck as loaded to go on camping trip--includes all passengers and 'stuff' in truck and bed + fuel and hitch.
Once you have this actual weight (or pretty close number) then you will know how much capacity is available for the trailer.
Also, when you get the truck weighed, be sure to put the front and rear axles on different pads of the scales--front tires on first section, rear tires on second section--this will get you the actual numbers on the separate axles, and particularly the rear axle number.
With the rear axle Weight Rating (RAWR--6100) less the number from your scale weight gives you the actual available weight you can put on the rear axle due to pin weight of the fifth wheel. That RAWR can be pushed some because the actual rear axle weight capacity from the axle mfg is almost always higher then the vehicle mfg puts on it--but you need to look at your tires and find out the max weight capacity for them--X 2 will give you the weight number on the rear axle you should NEVER go over--usually this will be around 7000-7200.
Think this thru--go weigh your truck, loaded if possible, run the numbers and see what is left for trailer pin weight.
As Stripit said, there are many 250/2500 series truck pulling way heavy fifth wheels and not falling by the wayside--up to you how far to push the numbers and how concerned about running near/over the tire capacity you are. Also, as Stripit said, when shopping new/used units--always use the Gross Vehicle Weight Rating (GVWR) as the possibly highest weight and take 20% of that as the expected pin weight.

Lot of numbers to consider, but if you do it often enough, it will make sense.....

 

[lanedawg]

Thanks Wingnut

I will do as you say, weigh the truck loaded with -Hitch, passengers, full fuel and any bags the kids have to have in backseat. Then I can decide what to do on my findings. I have had 50-50 positive & negative on the responses. I thank you again for the detailed explanation on the formula to success. When I know, I'll post the findings.

 

[wingnut60]

It is a confusing situation to deal with, but it usually is a one-time deal unless you make a major change in tow vehicle or trailer.

Another item to think about is the tires on the trailer you purchase--before finalizing any deal from a dealer, make sure the tires are not some off-brand and have plenty of capacity to haul the GVWR less the pin weight. Good tire brands are mentioned on many forums, and since you will be getting a lighter fifth wheel, the tires will probably be 16" Load Range 'E' Try to stay away from Chinese mfg, you will be happier in the long run. Michelin/Goodyear/Bridgestone are good, but pricey. Maxxis and Sailun are cheaper but have good reviews--I run Sailuns on my Suites and my 450 truck.

Just another item to consider....

Joe

 

[lanedawg]

Wingnut........just went an looked at the tire load range numbers on my truck. the sidewall says 3750# @ 80 psi for single and 3415# @ 80 psi for double ( dual ). Guess I would use single since my truck is an SRW? The Eagle HT I was looking at buying will have 16" Goodyear tires on it. So thats' a plus. SO if I use 3750# x 2 = 7500# max weight on rear axle, is that right ?

 

[wingnut60]

landdawg,
Your tires are about as good as it gets in a 16" tire for load capacity--there might be some higher if you went to a larger 16" but not much to gain.
So, you have 7500lbs of tire capacity on the rear axle--this should be the maximum weight on the axle at any time when you include all inside and bed contents AND the pin weight from any fifth wheel you want to use. But it needs to be said--if you run a tire near or at its load capacity, it has to be at the psi shown on the sidewall; even then, the tire life will be lessened if run at max load all the time. This is just like anything else--if you stress an item too long at max load, it will probably fail sooner than later. Don't mean to scare you too much, but the internet RV forums are full of examples of blown tires on trailers and the resulting damage.
Good luck in the search for a fiver that will fit the truck.

 

[lanedawg]

Thanks Wingnut......I'm sure everything will work out. If this Eagle HT is designed to be pulled with a half ton truck, I just don't understand why an F250 can't do the job safely. But to me safe travel with family onboard comes first. Everyone on this forum has been very helpful and I appreciate all of your opinions very much. I'll keep you guys updated on my adventure .........