Jeep Wrangler Tongue Weight and Tow Capacity

System · April 2021

This discussion was created from comments split from: tire storage.

AnOldUR · March 2021

Sharon_is_SAM said:

... remember to deduct the tongue weight from the payload weight.

This statement sent me on a wild google search, but came up more confused. More opinions than facts.

My TV has a towing limit of 2000 lbs and tongue weight limit of 200 lbs. If 200 lbs is on the hitch, it only makes sense that I'm not towing that weight. It won't contribute to sway or other trailer related forces. So, I'm not actually towing 2000 lbs, but 1800 lbs. I realize that I have to stay under the GCWR (Gross Combined Weight Rating), but can tongue weight be subtracted from the trailer weight when figuring my GTW (Gross Trailer Weight)?

(Hoping this isn't too far off-topic.)

Sharon_is_SAM · March 2021

@AnOldUR - how much your TV is rated to tow is different from how much weight your TV can carry on it’s axles and frame. Payload is GVWR - Curb weight. Each manufacturer determines how curb weight is defined - some include the driver. So, our Sienna calculates like this:

Gross vehicle weight rating: 5,995 lbs - Curb weight: 4,450 lbs = 1545# of allowable payload then subtract 250# tongue weight = 1295# for people and cargo.

A WDH will allow your TaB to carry some of the load, so the tongue weight will contribute less to the payload.

http://changingears.com/rv-sec-tow-vehicles-understand.shtml

GTW: Gross Trailer Weight (Includes Tongue Weight)

GTW Includes

All GAW's
Tongue Weight or King Ping Weight
Weight on all deployed jacks

Gross Trailer Weight (GTW) is the same as Gross Vehicle Weight (GVW) when referring to a trailer. While GVW can be applied to tow vehicles and trailers, GTW makes it clear that we are speaking of a trailer.

When connected, a portion of the trailer's weight is transferred to the tow vehicle through the hitch. In this case the GTW includes all axle GAW's and the Tongue Weight or King Pin Weight.

When not connected to the tow vehicle, the trailer's weight rests on its own tires and on all deployed support and stabilizing jacks. If you are weighing a trailer without the tow vehicle, be sure to place the entire unit on the scale, including all jacks.

AnOldUR · April 2021

@Sharon_is_SAM ... My old brain got the acronyms wrong when I wrote, "... can tongue weight be subtracted from the trailer weight when figuring my GTW ?" What I meant was, can tongue weight be subtracted from the TV's trailer weight rating? My Jeep owners manual says the Maximum Trailer Weight Rating is 2000 lbs and the Gross Combined Weight Rating is 8016 lbs. The Jeeps Curb Weight is 3879 lbs. Subtracting the Curb Weight from the Combined Weight ratings leaves me with over 4000 lbs for payload, passengers and towing. In my brain, if I transfer 200 lbs of the trailer weight to the TV in the form of tongue weights, that weight no longer contributes to the trailer weight. It's now part of the combined weight.

I know this sounds petty to some of you, but when the weights and limits are this low, 200 lbs makes a difference in how you pack. I'm confident that I can keep my unhitched trailer weight to under 2000 lbs, but it would be nice to know that I have another 200 lbs of cushion when packing.

Denny16 · April 2021

No, the tongue weight can no be deducted from the trailer’s total weight when figuring maximum trailer weight that can be towed, The trsiler weight is the dry curb weight of of the trailer, and its contents or trailer cargo, including water, propane and what ever you put into the trailer, as measured in the trailer’s axle. The 200 lbs of tongue weight is still part of the trailer’s total weight, as measured on the trailer’s axle. The cargo weight of your keep includes the tong weight, as it is pressing down on the Jeep’s rear axle.

So the tongue weight, and any cargo in the back of the keep that is pressing down on the Jeeps rear axle is cargo weight on the rear axle, including the weight of the Jeep, as measured on the rear axle. The total weight of the Jeep, plus it’s cargo (and trailer tongue weight, including passengers is the GVW. The Jeep has three max weight ratings, one for, the front axle, one for the rear axle, and a total weight for both axles or GVW. You need to keep the Jeep’s cargo and passengers balanced so the weight is distributed properly on both axles. The total trailer weight is the weight measured on its axle.

While the tongue may distribute some of the trailer’s weight on the rear axle of the tow vehicle, it is still part of the total trailer’s weight, for figuring the maximum trailer weight being towed.
cheers

Sharon_is_SAM · April 2021

@AnOldUR - sorry. I replied yesterday and the post was lost. I could not find any listing of 2013 Jeep Wranglers with a 2000# Tow Capacity and a 8000# GCWR. I found a 6029# GCWR with a 2000# Tow Capacity and a 1000# payload. Also, another number to consider is the Frontal Cross Section Area limit of 25 sq ft.

As Denny posted, the tongue weight is part of the TaB Gross Trailer Weight and can not be subtracted from the Jeep Tow Capacity.

Here is a link to others who tow with a limited capacity. I think when the weights and limits are so narrow, you should reconsider the safety of towing a TaB with a 2000# capacity. Please keep in mind, you may be able to tow on the flat at a lower speed comfortably, but quickly stopping your TV/Trailer combo is really a true test of your TV ability to tow. Good luck.

https://tab-rv.vanillacommunity.com/discussion/comment/89894#Comment_89894

AnOldUR · April 2021

Sharon_is_SAM said:As Denny posted, the tongue weight is part of the TaB Gross Trailer Weight and can not be subtracted from the Jeep Tow Capacity.

Not that I doubt it's true, but I just wish I could understand the logic behind this statement. My brain keeps telling me that if some of the weight is transferred to the rear axle of the tow vehicle, then I'm no longer towing that weight.

The chart from an owners manual that's attached below is what I was basing my numbers on. I should have dug deeper. Before now, I hadn't seen the link that you posted in the other thread. Looking at those charts brings up more questions than answers. Why would an axle ration swap in a 2013 not change the GCWR, but going from a 3.21 to a 3.73 in a 2016 bumps the GCWR from 6900 lbs to 8400 lbs? I'll keep digging. Thanks for the replies and additional information.

Image: https://us.v-cdn.net/5021717/uploads/editor/w5/dk9nzb383p9v.jpg

GatorEgg · April 2021

If you’re actually that close to ratings you need to go vehicle shopping.
1. Most experts recommend a trailer no more than 1/2 vehicle rated towing capacity. This allows for loading and a safety factor.
2. Jeep’s also have a trailer frontal area size limitation. Check owners manual for specific year limits.
3. If you do decide to put aside safety, make sure you only kill yourself, not others.

AnOldUR · April 2021

As a backyard engineer I need to know if this forum has an ignore function?

Dutch061 · April 2021

The possible difference between the GCWR from 2013 to 2016 with the axle ratio change could be engine HP and Torque or the actual engine option. IE 2013 only had a 4 cylinder but the 2016 had that and a V-6. For most manufacturers, the HP and Torque have gone up almost on an annual basis.

There also may be a suspension change with the lower gear ratio on the newer model year that allowed for the increase.

Brad

Denny16 · April 2021

Mate, already, regardless of max tow capacity and tongue weight limits, your two-door Jeep Wrangler has a 20 sq.ft front area limit, the TaB320 (as Sharon pointed out) has a 25 sq.ft frontal area. So right off the line, you are out of spec towing a 320. The newer Wranglers have a different axle load limit and suspension setup, which gives them a better rating with the lower gear ratio setup. Same holds true for the Jeep Gladiator, the MaxTow version has a different front and rear axle over the standard model, in addition to the lower gear setup.

That said, you could probably safely tow a TaB320 at low speeds, with carful loading of both the Jeep and trailer, keeping it on the minimal loading side. I would not go faster than 45mph, so the frontal area is not as big an issue. Off road again probably OK, as you are going lower speeds. A good way to judge this, is to connect the TaB to the Jeep and see if the Jeep remains fairly level with the trailer attached. If your rear end goes down more than 2 inches out of level, or the front end ends up noticeably lifting up, then your trailer tongue weight is too much. I would try this with the Jeep and trailer unloaded first.

The trailer axle load weight is measured on a scale with just the axle/wheels on the scale, not the tongue/Jack. So while you are correct in that part of the trailer weight is being supported by the tongue Jack/hitch, this weight is listed and used separately from the axle load rating. The TV max two capacity is determined by the amount of trailer weight sitting on its axles/wheels. So if your trailer weight over the axle is 1800 lbs and the tongue hitch weight is 200 lbs, than the total weight of the trailer is 2,000 lbs. but in towing, only 1800 lbs is on the trailer axle/wheels, the other 200 lbs is on the TV. This is why you have both ratings, and the tongue weight limit is normally set at 10% of the total towing capacity, which is an average minimum safe tongue weight for towing here in North America and Australia.

In Europe/UK they use a lighter tongue weight by extending the tongue and adjusting the axle location, and they tow at slower speeds, so the limit is based on their towing practices. If you keep your Jeep and TaB320 off the high speed highways, and travel the back roads at 45mph or less, with the trailer brakes working properly, you may be fine, but this is at your risk! I am not saying this would be totally safe. That depends on the situation and towing conditions, as all towing limits are based on average conditions and the TV ability to pull a given load up a given grade at highway speeds of 55-65mph.
Cheers

Tabulating · April 2021

When I think of Gross Trailer Weight, I focus on the word gross. Just like my gross income, it includes everything before deductions.

So, if the IRS was evaluating your math, it would not allow the tongue weight deduction.

I am a guy that believes the engineers and lawyers are good at their jobs. So, I would never tow in gray area. Too much risk for me and others. The limits are limits.

Bill

Denny16 · April 2021

Good advice... better to be safe and avoid any unnecessary risks. I was just giving the options for the OP to evaluate. Personally, I wouldn’t take an at limit rig on the road. I wouldn’t want to drive that older Jeep on the highway even with out a trailer, let alone with a RV trailer like the Tab. Been there, done that with a CJ2 and a box utility trailer designed for a Jeep off road. On the desert this rig was great, going down the highway to get to desert, was a pain, that Jeep would beat you to death at 55mph !

AnOleUR would be better off buying a trailer a Taxa Tiger Moth Overland to tow behind his Jeep, and leave the TaB320 to a bigger TV. He could always do what I did, and buy a Jeep Gladiator truck, which has enough capability to tow a TaB400, so a 320 would be very safe and enjoyable to tow.

AnOldUR · April 2021

Denny16 said:

... your two-door Jeep Wrangler has a 20 sq.ft front area limit, the TaB320 (as Sharon pointed out) has a 25 sq.ft frontal area. So right off the line, you are out of spec towing a 320 ...

Actually, my year/model has a 25 sq.ft. limit. Regardless, do you subtract the TV’s frontal area? I’ve seen it stated both ways when searching. My boxy Jeep is so big and close to the trailer that it seems it would block the majority of any head wind.

Sharon_is_SAM · April 2021

I grabbed this Ford quote from another forum:

Frontal Area is the total area in square feet that a moving vehicle and trailer exposes to air resistance.”

I take that to mean you add the TV frontal area to the TaB area that is exposed beyond the TV.
Exceeding the specified limitation may significantly reduce tow vehicle performance. How significantly is anyone’s guess.

AnOldUR · April 2021

@Sharon_is_SAM ... That’s how I would interpret it also. The problem is that the Jeep’s frontal area alone is already over the limit. Confusing to say the least. Would make more sense if it were the area of the trailer not blocked by the Jeep, but without clarity from Jeep, it’s all speculation.

edit to add that on this first outing we cruised at between 55 and 60 mph on the highway. No problems with either too much load or sway when being passed by big rigs moving considerably faster.

Denny16 · April 2021

The trailer frontal area is separate from the TV. So if you have a trailer frontal area of 25 sq ft, and your towing specs allow for 25 sq.ft., then you are good to go. Air does not move in a straight line, it curves and flows around objects. The amount of air shifted by the Jeep body was already calculated when determine the TV frontal area limit. This limit is the front area of the trailer that blocks airflow. On an RV this would be from the trailer tongue to the top of the front. The roof curve on a TaB helps reduce the frontal area drag, but is still part of the front area.

The TV does not effectively block air from hitting a trailer four to six feet behind it. For the Jeep to create an air drafting effect for a trailer, thst raider would need to be less than a foot behind it. That is why big tractor/trailer rigs have the air shrouds between the tractor and trailer, to create a drafting zone for the trailer, reducing the amount of air thst gets between the tractor TV and the trailer. Wind tunnel models with smoke are grand for showing the air flow effects around TV and trailers.
cheers

MuttonChops · April 2021

I agree with @Denny16 's clear explanation of Frontal Area.

Ignore the TV frontal area.

Also note Frontal Area has more to do with overall TV performance (acceleration, MPG) than dangerous or damaging to the TV. When one tows above the recommended frontal area drive at slower speeds and expect very poor MPG.

This is not to say that a two-door Jeep is a safe/ideal towing vehicle . . . might be OK for older (lighter) T@Bs, questionable for today's full feature models.

Sharon_is_SAM · April 2021

Does anyone know a good source for locating frontal area? I can not find it for the Sienna even though it seems like we passed muster with this value.

MuttonChops · April 2021

Sharon_is_SAM said:

Does anyone know a good source for locating frontal area?

Short answer is no. Ford seems to be the only manufacturer that provides the data regularly; normally in the yearly towing guide publication. Once in a while another USA manufacturer publishes the data on a specific vehicle.

What I've done / do is use Ford data if a specific vehicle data is not available. Ford lists lots of vehicle types so one can find a Ford vehicle or two about the same size/class/power as your non-Ford vehicle - - - then use that frontal area data. Which is better than no data.

Denny16 · April 2021

MuttonChops, thanks for,the compliment on the frontal area explication.

Jeep and Dodge tucks have the trailer frontal area data in the vehicle’s manual. Cargo capacity is on the door sticker of most trucks and SUVs. Try looking in ykur vehicles owner’s manual, under specifications .
Cheers

AnOldUR · April 2021

Denny16 said:

That is why big tractor/trailer rigs have the air shrouds between the tractor and trailer, to create a drafting zone for the trailer, reducing the amount of air that gets between the tractor TV and the trailer.

Thanks for the explanation. In searching for more information on aerodynamic I saw wind foils on pickup truck cabs (with nothing over the bed) to increase gas mileage while towing. Makes me wonder if they are actually effective considering the distance between the foil and trailer.

Denny16 · April 2021

Good question, might be fore of a cosmetic thing on smaller pickup trucks than an actual improvement... Like the spoilers,you see on small street sprouts coupes, that only work when you are driving more than 80 to 100 mph!
cheers

DougH · April 2021

Up to 3mpg savings advertised on this brand name. And they couldn't say it on the Internet if it wasn't true.

https://www.campingworld.com/48-x-22-wind-deflector-black-68798.html

AnOldUR · April 2021

MuttonChops said:
When one tows above the recommended frontal area drive at slower speeds and expect very poor MPG.

For reference, this past weekend we put in about 250 miles of mostly flat towing with a mix of back roads and highway driving. Under similar conditions when not towing our Jeep gets something shy of 20mpg. For this trip while towing we averaged 16.5mpg. I’m not sure if the weight or frontal area had the majority of the impact, but in my limited experience, I don’t think that’s too bad.

Side note. I’ve been trying to find someone to swap out our Jeep’s gears from 3.21 to 3.73 without luck. Fingers crossed that the guy I spoke to a couple of days ago is willing to take on the job and comes through with reasonable price quote.

4ncar · April 2021

@AnOldUR: I’m surprised you are having trouble willing or able to swap out the ring & pinion gears. Try an off road specialty shop. FYI, if you do the rear, you need to do the front as well(just in case you weren’t aware).

AnOldUR · April 2021

@4ncar ... l was also surprised to find it so difficult to get this done. The mechanic that I have used for years said he’s not equipped to do it. Got the same reaction from several other shops that advertised that they do transmission work. I did find a trans shop that will do it, but they’re pricey and backed up for two months. It might be the last resort that I’m forced to go with.

The need to do both the front and rear was not something I was aware of going into this, but did discover along the way. Still, thanks for mentioning since I could have missed it.

rcuomo · April 2021

AnOldUr- a little bit of a trip but K&M performance in Fitzwilliam NH has tons of experience handling that swap. Paul Haynes is the GM.

4ncar · April 2021

@AnOldUR: I too can refer GAS(general automotive service) in Gaithersburg, md. Still a drive...

AnOldUR · April 2021

Found a real hole-in-the-wall (and that’s being polite) local trans guy, but he was highly recommended. I ordered the parts from Randy’s Worldwide and had them drop shipped to his shop. Went with the 4.10 gears. Fingers crossed that everything works out. If not I’ll be looking into the other options suggested here. Thanks.

N7SHG_Ham · April 2021

Randy's is the bomb. I had a pinion seal replaced at the HQ in WA. They got me in on an emergency basis and hasn't leaked sense. When my Dana axles need work, I will drive from Oregon to the shop. 1st actual axle work that I felt good about the shop, these guys know axles. A bit far from east coast, but your parts supplier is best in business IMO.

Howdy, Stranger!

Quick Links

Categories

Jeep Wrangler Tongue Weight and Tow Capacity

Comments

GTW: Gross Trailer Weight (Includes Tongue Weight)