Ron Gratz
full time RVer
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Chuck&Gail wrote:But, the manufacturer of the vehicle receiver AND the manufacturer of the vehicle, take that into account with their specs. Tongue weight spec should not ever be exceeded IMHO, no matter how the numbers are spun. I don't think anyone is saying the "tongue weight spec" should be exceeded. And, no numbers are being "spun".
If you are presuming to define what a TV manufacturer means by "tongue weight" or "hitch weight" -- I think that should be left up to the TV manufacturer.
My post only addresses the OP's question --
Is there a way to actually find out the weight on the hitch with the WD hitch bars connected to the vehicle and trailer?
Ron
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clearnetedm
Alberta
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It's actually a interesting thread. I certainly agree about never exceeded any weight limit. However for the sake if discussion id like to consider the following. If you weight your trailers TW with a scale you will get a value we will call X. That would be the dead weight on the ball and the respective weight limit for that. However when you apply the WD system you now have a differen TW on the ball we will call Y. Y should be less than X Which one could calculate and possibly now within the WD carringing limit of the hitch. Again just for the sake of discussion or am I missing something?
2008 Ford Expy EL
2012 Rockwood 2601S
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Sea'scape
Vancouver Island
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clearnetedm wrote:It's actually a interesting thread. I certainly agree about never exceeded any weight limit. However for the sake if discussion id like to consider the following. If you weight your trailers TW with a scale you will get a value we will call X. That would be the dead weight on the ball and the respective weight limit for that. However when you apply the WD system you now have a differen TW on the ball we will call Y. Y should be less than X Which one could calculate and possibly now within the WD carringing limit of the hitch. Again just for the sake of discussion or am I missing something?
You have it correct. Hitch manufacturers do the calculation and provide the information differently. Often the weight capacity for a receiver hitch is given as follows;
Weight Carrying
Weight carrying max trailer - 5000 lbs
Max tongue load - 500 lbs
Weight Distributing
Weight distributing maximum trailer - 11300 lbs
Max tongue load - 1130 lbs
The above is for the hitch only, and does not say that the tow vehicle can handle that load. In most (many?) cases the tow vehicle can handle significantly less.
When I calculated what I could tow, the vehicle GVWR was the determining factor, and the trailer size was a lot less than was given by the vehicle max towing capacity. Maximum towing capacity is with vehicle unloaded, and only the driver.
The other rating that surprised me was the frontal area of the trailer. A good argument for low drag front end on the trailer.
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earnold333
Denver Co & Chandler AZ
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Wow! Thanks for all al the comments, but i am still confused. I have a Mercedes ML350 bluetec diesel. The manual says the max total tow weight is 7200 #, and the hitch weight is 576. The trailer I would like to buy actually weighs 6136# , which I am told is based on actual weighing after the options etc were added. The mfgs brochure for the trailer says the base weight is 5674#, the carrying capacity is 1478#, and the hitch is 653#. There are only 2 of us and we don't have much stuff in the trailer. I can't imagine we would ever have more than 600 # of stuff, even with a little water and the propane. So I think I am ok with the total weight. But am I in danger with the hitch weight, and should that stop me from buying this trailer? The trailer I currently have is a little smaller and according to the brochure has a base weight of 5014, carrying capacity of 1522, and hitch weight of 580. I am usually always able to go the speed limit, and have trouble only on long steep hills. I slow down to 30-35 going up to the Eisenhower tunnel from Dillon, for example, or up Vail pass, but the car doesn't overheat.
Is is too much of a stretch to get this trailer? Thanks for all your help.
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Ron Gratz
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earnold333 wrote:Wow! Thanks for all al the comments, but i am still confused. I have a Mercedes ML350 bluetec diesel. The manual says the max total tow weight is 7200 #, and the hitch weight is 576. The trailer I would like to buy actually weighs 6136# , which I am told is based on actual weighing after the options etc were added.--- Let's assume the "empty weight" actually is 6136# and you add slightly less than 600# of stuff, bringing the loaded weight up to 6700#. The corresponding loaded tongue weight might be around 850#.
With weight distribution applied, the 850# TW might result in a load of 200# being added to the trailer's axles and a load of 650# being carried by the tow vehicle.
If the manufacturer's "hitch weight" specification of 576# actually pertains to the trailer's tongue weight, you would exceed the specification by about 275#. If the specification pertains to the amount of load added to the receiver, you would exceed the specification by about 75# -- not including the weight of the WD hitch.
I think you really need to determine the TV manufacturer's meaning of "hitch weight". Also, what does the Owner's Manual say about the use of a weight distribution hitch on this vehicle?
Ron
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Sea'scape
Vancouver Island
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I did a bit of looking for data on your vehicle and what I found is unclear. I can understand your confusion.
A couple of suggestions;
1. look carefully at your hitch and see if there are any ratings stamped or marked on it. A quote follows from a hitch manufacturer page that states not all Class 3 hitches are rated for weight distributing.
The specification for your Mercedes only states that it is a Class 3 hitch that can tow 7200 lbs. It does not state what the hitch rating is.
2. Look at the rating sticker on the door pillar. This should state the maximum loaded weight of your vehicle (GVWR). Subtract your base weight from this and it will tell you what the maximum carrying capacity is. Mercedes defines the curb weight as containing all accessories, options, full fuel tank, etc. It does not state whether the driver is part of the curb weight. as some other specs do.
After calculating difference, the full hitch weight, the occupants and the cargo weights should be less.
Good luck.
Quote from one hitch manufacturer, indicating possible confusion.
Class III
Class III hitches are weight carrying (WC) and also are weight distributing (WD) hitches depending on the vehicle and hitch specifications. Not all Class III hitches are rated to be both. The hitch specifications will alert you to a hitch that is not weight distributing. Class III hitches used as weight carrying is rated up to 6000 lbs. gross trailer weight (GTW) with a maximum trailer tongue weight (TW) of 600 lbs. Hitches that are used for weight distributing are rated up to 10,000 lbs. gross trailer weight (GTW) with a maximum trailer tongue weight (TW) of 1000 lbs. The use of a ball mount and hitch ball of the same rating or higher is required. To use the weight distribution side of the hitch a weight distribution system is required. Class III hitches attach to the vehicle frame only. Always consult your owner's manual for vehicle rating.
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goducks10
Keizer OR
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I would think that the TW rating would be 720lbs if the tow rating is 7200lbs. 10% is the min TW by most manufaturers. Anything less could result in poor towing and I doubt Mercedes would justify an owner having less than 10% on their tongue. If the TW rating is less than 720 lbs then the 7200lb tow rating is useless.
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padave
Richland PA
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Basically....buy a new tow vehicle or buy a hybrid......Mercedes were not made to tow trailers. You will be over weight and the weight of the trailer will throw you around like a rag doll.....especially in a wind storm. Sorry.
wife and 2 daughters
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Chuck&Gail
In the Colorado Mountains
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It is unfortunate that Mercedes changed their SUV so much. We loved our 1999 ML320 which had a hitch and vehicle rating of 750#, WDH or weight bearing, per manufacturer, we asked. Took awhile to get an answer, but that was in 1999. We used that ML320 to tow over 100,000 happy miles. It is still used as a daily driver, and now has over 200,000 miles on it.
When we bought a new heavier TT in 2010 we went to our dealer to buy a new Mercedes with the higher tow rating, only to find out the tongue weight rating had DECREASED! Dealer checked several times, but it seems frame and all were changed over the years. We did notice the 2010 Mercedes was SMALLER than our 1999. We bought a Ford Expedition.
Chuck
Wonderful Wife
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2010 Outback 230RS Toybox, 5390# UVW, 6800# Loaded
Not yet camped in Hawaii, 2 Canada Provinces, & 2 Territories
I can't be lost because I don't care where this lovely road is going
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ripperoo
Akron, Ohio
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goducks10 wrote:I would think that the TW rating would be 720lbs if the tow rating is 7200lbs. 10% is the min TW by most manufaturers. Anything less could result in poor towing and I doubt Mercedes would justify an owner having less than 10% on their tongue. If the TW rating is less than 720 lbs then the 7200lb tow rating is useless.
Actually, it is possible to safely tow a 7,200# trailer with as little as 10# of tongue weight. If he's towing a 4 wheel trailer like a hay wagon. I think that's why ther might be a difference in towing capacity vs. matched tongue weight capacity.
2012 Ford F250 Super Duty, SC 4x4 XLT, 6.2L, 3.73 gears
2011 Keystone Sprinter Select 29BH
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