Sorry to be a pest, but another question to check on methodology; not really interested in a Ford vs RAM truck dust up. I'm looking to buy a 1 ton to tow a 5th wheel. I want to know the math behind a manufacturers published tow ratings between conventional towing (tow behind) vs. a 5th wheel. It's confusing as Ford publishes these two different ratings, but RAM does not appear to. RAM is just one tow rating number and, since I'm not sure about the math and best practices, I don't know how best to interpret RAM's figure. For example, Ford's 2014 diesel F350, auto transmission 4x4 6.7L DRW 3.73 axle ratio is conventionally rated to tow 18,500 and on a 5th wheel, 22,200. It looks like Ford took 20% of 18,500 and added that back, to get 22,200 (18.5 + 3.7=22.2). I'm guessing this 3,700 pin weight was allocated to the tow vehicle, thereby increasing the 5th wheel tow rating. Am I correct? If so, how many times is the pin weight counted in the GCWR? (e.g., is the 3,700 pin a deduction from both truck and trailer; a total 7,400 against the GCWR?)RAM's comparable 2014 3500 AISIN (auto transmission) DRW 3.73 is rated to tow 23,500, based on the chart in the marketing brochure I got at the dealer. RAM just provides this one figure, so how does this single figure compare to Fords' fifth wheel figure? I just want my calculations to be apples to apples, not looking at brands here, with the intent of towing a 5th wheel. Thanks

I don't think you will ever know how they come up with their numbers unless you work in their marketing department. And they can change the numbers as their competitor's numbers change. Doesn't matter which brand you are looking at.

IMHO towing ratings are unimportant when it comes to towing a fifth wheel.What you need to know are three things.Real ready to travel weight of the truck.GVWR of the truck.Real ready to travel pin weight of the fifth wheel.Lacking any of these items and you are only going to be guessing.Lacking this information you might make a couple of assumptions and be close.The current crop of 1 ton SRW crew cab truck with diesel and automatic is going to scale ready to travel right around 8000 pounds.So, subtract from the GVWR 8000 pounds and generally speaking you are going to have around 2000-2500 Cargo Carrying Capacity (CCC)Again generally speaking a fifth wheel is going to have between 17 and 25% of it's total weight as pin weight. Most folks consider 20% a good place to start. So, using my example above of 2000 pounds CCC on the truck and basing on 20% means you can tow a 10,000 GVWR fiver.This is all based on a lot of assumptions and assumes you want to stay within manufacturers numbers otherwise you probably would have never asked the question in the first place.

You 'tow' a trailer and tongue weight is lower plus use WD to adjust weight on truckYou 'carry' & tow a 5th wheel.......all pin weight is carried on rear axle (tires, axle, springs)MFG. published MAX Tow Ratings are a misnomer and marketing hype."Maximum trailer weights in pounds for properly equipped vehicles with no cargo""Make sure vehicle payload (reduce by option weight) will accommodate trailer tongue (trailer king pin for 5th-wheel towing) load weight and weight of passengers and cargo added to towing vehicle. Addition of trailer tongue (trailer king pin for 5th-wheel towing) load weight and weight of passengers and cargo cannot cause vehicle weights to exceed rear GAWR or GVWR."Trucks GVWR, RAWR, Tire Max Load Ratings and 'actual' payload available are the important numbers when matching truck/trailer.

Pin weight is not added twice. One number (tow behind maximum) has nothing to do with the other(fifth wheel maximum).

donn0128 wrote:IMHO towing ratings are unimportant when it comes to towing a fifth wheel.I think that is not true for a 1-ton DRW.The 2014 F-350 DRW 6.7L 4x4-174.2 has a curb weight of 8,195# and a GCWR of 30,500#.This means that with only a 150# driver and no optional equipment or cargo, the trailer weight would be limited to 30500-8195 = 22,305#.The 14,000# GVWR of the same TV would allow a maximum pin weight of 14000-8195 = 5805#.The corresponding trailer weight at 20% pin weight would be 29,025#.The 9650# rear GAWR combined with a rear Curb Weight of 3453#, would allow a pin weight of 9650-3453 = 6197#.The corresponding trailer weight at 20% pin weight would be 30,985#.So, "tow ratings" are important when it comes to towing a fifth wheel if the candidate TV, as in the OP's case, is a DRW.The current crop of 1 ton SRW crew cab truck with diesel and automatic is going to scale ready to travel right around 8000 pounds.So, subtract from the GVWR 8000 pounds and generally speaking you are going to have around 2000-2500 Cargo Carrying Capacity (CCC)---Again, the OP is talking about a DRW.Ron

calculating trailer vs 5th wheel towing capacity question

13 Replies

Old-Biscuit
Explorer III
Apr 11, 2014
You 'tow' a trailer and tongue weight is lower plus use WD to adjust weight on truck

You 'carry' & tow a 5th wheel.......all pin weight is carried on rear axle (tires, axle, springs)

MFG. published MAX Tow Ratings are a misnomer and marketing hype.
"Maximum trailer weights in pounds for properly equipped vehicles with no cargo"
"Make sure vehicle payload (reduce by option weight) will accommodate trailer tongue (trailer king pin for 5th-wheel towing) load weight and weight of passengers and cargo added to towing vehicle. Addition of trailer tongue (trailer king pin for 5th-wheel towing) load weight and weight of passengers and cargo cannot cause vehicle weights to exceed rear GAWR or GVWR."

Trucks GVWR, RAWR, Tire Max Load Ratings and 'actual' payload available are the important numbers when matching truck/trailer.
donn0128
Explorer II
Apr 11, 2014
IMHO towing ratings are unimportant when it comes to towing a fifth wheel.
What you need to know are three things.
Real ready to travel weight of the truck.
GVWR of the truck.
Real ready to travel pin weight of the fifth wheel.
Lacking any of these items and you are only going to be guessing.

Lacking this information you might make a couple of assumptions and be close.
The current crop of 1 ton SRW crew cab truck with diesel and automatic is going to scale ready to travel right around 8000 pounds.
So, subtract from the GVWR 8000 pounds and generally speaking you are going to have around 2000-2500 Cargo Carrying Capacity (CCC)
Again generally speaking a fifth wheel is going to have between 17 and 25% of it's total weight as pin weight. Most folks consider 20% a good place to start. So, using my example above of 2000 pounds CCC on the truck and basing on 20% means you can tow a 10,000 GVWR fiver.
This is all based on a lot of assumptions and assumes you want to stay within manufacturers numbers otherwise you probably would have never asked the question in the first place.
BB_TX
Nomad
Apr 11, 2014
I don't think you will ever know how they come up with their numbers unless you work in their marketing department. And they can change the numbers as their competitor's numbers change. Doesn't matter which brand you are looking at.

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calculating trailer vs 5th wheel towing capacity question

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