Factory tow ratings apparently assume empty tow vehicle

[Boomerweps]

Too much time on my hands under semi house arrest 😉

Based on reviews of a few Ford Towing Guides:
The tow rating for a truck plus it's EMPTY weight equals it's GCWR!

Example: my truck, 2019 F150 5.0 3.55 axle towing package SuperCrew 145" WB
GVWR 7000# CC 1990#
Tow rating by chart 9100#
BUT per that same chart GCWR 14500#
GCWR minus GVWR equals 7500# left for towing if the truck is fully loaded.
Since GVWR minus Cargo Capacity should equal truck empty weight (with gas full tank), 7000 - 1990 = 5010.
So empty weight 5010 plus tow rating 9100 equals 14110, close to the GCWR listed at 14500.

This also explains why my same trailer towed the way it did with my Explorer, struggling half the time.

2008 Explorer V6 3.73 axle towing package GVWR 6180#, CC 1452#, tow rating 5225# GCWR 10000#. CAT Scaled rig at 9600#.
So empty Explorer is 4728# plus tow rating equals 9953#, close to the GCWR OF 10000#. So as weighed, I was pretty close to GCWR towing with the Explorer!

This is all with a trailer that has a GTWR of 3877#, trailer axle was 3600# at the CAT.
Bought this trailer figuring I had a decent safety & capacity margin with a trailer at that GTWR & a tow rating of 5225#. GUESS NOT!

[noteven]

bikendan wrote:

noteven wrote:
My dually has a payload of 16,500lbs approx. so I round to the nearest 500...

:h

It’s a 160” wheelbase 4 passenger 2 door Kenworth, 12K front 21K rear, parks in the same footprint a DRW pickup needs, turns tighter than my 350/3500 pickups. Weighs around 14-15k unladen.

[APT]

Your actual towing limit is the least of several ratings. That is why the manufactures state "up to xxxxx pounds". RVers tend to exceed a different rating well under the tow rating for their vehicles.

[time2roll]

Keep your trailer GVWR within the tow rating for best results.
If you plan to have a person in every seatbelt and 500# of firewood you need to adjust for that too.
Always been this way, nothing new. Good to know one more RVer is getting clarity on this.

[blt2ski]

bikendan wrote:

noteven wrote:
My dually has a payload of 16,500lbs approx. so I round to the nearest 500...

:h

Easy, 20 on rear duals, upwards typically of 12k on front axle. My case IF I want to go that heavy, 32k gross less 12k empty, is 20,000 lbs of payload. I'll go to 14,000. Over that, things get really squirrely.

Marty

[bikendan]

noteven wrote:
My dually has a payload of 16,500lbs approx. so I round to the nearest 500...

:h

[Grit_dog]

noteven wrote:
My dually has a payload of 16,500lbs approx. so I round to the nearest 500...

Big dooley comin thru! K Whopper or Pete?

[noteven]

My dually has a payload of 16,500lbs approx. so I round to the nearest 500...

[blt2ski]

If at max gvw, you have NO ability per say to tow something, unless you can do it with zero lbs of hitch wiegt. If you need hitch weight added to tow rig, you have too small a tow rig

[BenK]

My opinions in addition to the good info already posted and congrats on figuring it out

Many...most newbies will take the brochure MTWR (Max Tow Weight Rating) as an absolute. Meaning that if it says your MTWR is 9,000 lbs...it applies to all conditions of how your TV is loaded

Not so, as you have found out. If the TV is loaded up to its GVWR, there is no room left in the ratings to tow a 9,000 lb trailer

OEMs are getting better...IMHO, think the warranty/service costs drove them to be a bit more realistic.

MTWR used to be based on the 'curb' weight of the TV. That meant a stripper model with NOTHING other than the trailer package. Marty is the only guy here that I've found to have owned one of those. Today, think that stripper is no longer available...where as it was the government that purchased them

Also, the GCWR is fairly new rating and is performance based, which IMHO has a warranty component. Mainly getting it going on the maximum conditions of everything. Ambient temp, incline, altitude, etc, etc.

Best is to load up the TV as if going RV'ing with people, pets, luggage, ice chests, etc, etc and go weigh it. Axle by axle. That will then provide the true base line to figure out that TV's MTWR and of course staying within the GAWR's

[Grit_dog]

This is a revelation?

[blt2ski]

Best way to figure out max trailer, is loaded truck from gvw. divide that mumber by HW % you need. if you have a 1000 lbs, 10% hw, gives you a max 10,000 lbs trailer. if pulling a 5W with say 25%hw, you have a whopping 4000 lbs max trailer!
Them advertisers are great at their jobs, leaving a lot of details out of the fine print!

Marty

[blt2ski]

No options, a fully loaded leather crew cab can add 500-100 lbs of wieght to the truck too!

Marty

[valhalla360]

Yes...other than assuming driver and full tank of fuel, it makes sense.

The max tow capability would be with an empty truck. Doesn't matter if you load 1 ton of cement blocks in a trailer or the bed of the truck...the engine will struggle just as much climbing the same hill.

If you read the posts on the forum, you will find this is well known and as often as not, the tow rating doesn't come into play. Particularly for 5th wheels it's payload that is the limiting factor and most people just laugh when they see 1/2 ton trucks with 10,000lb tow ratings because under normal circumstances it's near impossible to tow that much and keep the tongue weight high enough not to create a sway issue without exceeding payload capacity.

[ktmrfs]

and add to that:

TV mfg assume 10% tongue weight and around 20% pin weight

And the hitch weight needs to be added to the truck empty weight as well further reducing payload.

Then Trailer mfg typically design for 15% tongue weight and around 25% pin weight further upsetting the calculations.

So, it's pretty hard to be able to tow the max rated trailer even without anything else in the vehicle without going over GVWR and still be way under GCWR.

My duramax when loaded with typical bed stuff, firewood, firepit, cooler etc. along with a 9,000lb bumper pull with 1400lbs on the tongue and either 5 passengers, or my son and an additional motorcycle in the back is right at 10,000GVWR.