Interstate towing flying cloud

[SWH]

Originally Posted by uncle_bob

Hi



Be *very* careful moving around things to change tongue weight. People look at 10 to 15% as some sort of "magic" number that guarantees stability. It very much its nothing of the sort. The problem is far more complex. Moving weight to the far end of the trailer is likely to significantly impact stability. How big a deal is that in this case? Who knows .... could be a problem.



Bob

In fact interestingly the dry tongue weight of the Caravel 16RB is slightly more than 15% of dry trailer weight as designed by Airstream. Given the largest storage space in the trailer is in the rear under the bed I have to assume the engineers anticipated weight being loaded in the rear. But yes I will be careful.

[uncle_bob]

Originally Posted by SWH

In fact interestingly the dry tongue weight of the Caravel 16RB is slightly more than 15% of dry trailer weight as designed by Airstream. Given the largest storage space in the trailer is in the rear under the bed I have to assume the engineers anticipated weight being loaded in the rear. But yes I will be careful.

Hi

Again, there is no magic in that 15% number. 20% may well result in a more stable trailer. <5% is likely to create interesting issues, regardless of what it does to stability. What sort of interesting issues you ask? Well mom and dad walk to the back of the trailer. Up goes the tongue and they find out if the remembered to chock the wheels.

On most AS designs, a fully loaded trailer is *heavier* on the tongue when ready to travel than it was dry. All that I've seen do have rear storage ....

Bob

[AA13]

Originally Posted by uncle_bob

Hi

I suspect you *will* need to dive into the same set of numbers I outlined on the modern GT. It's not a single number on any of the van's I've seen. With any sort of reasonable loading in the van, towing likely is impacted.

In terms of why somebody made a mistake? Maybe it was their first day on the job ... who knows

Bob

Thanks for the info Uncle Bob!

I just called Airstream again to verify numbers as I want to make sure I’m looking at things correctly.

As you seem quite knowledgeable wanted to run them by you one last time.

The 2013 AI lounge model was built on a Mercedes 3500 chassis (not the 2500). Airstream again verified the tow weight is 7500 (I mistyped above when I wrote 7400). They also verified the tongue weight is 750 pounds. This is also what Mercedes lists for the 3500 lounge model for 2012 (chassis year).

Dry weight of AI lounge model is 8860.
Dry weight of 23fb is 4806.

The hitch weight of the trailer is 467. I know this can change and will weigh it before taking off!

From what I gather, I want to keep hitch and tongue weight at 10% to 20% under tongue and tow weight.

So… 600-675 max tongue and 6000-6400 max towing. I say 6400 as that is the number listed in our brochure.

Does this sound correct in your experience?

[Wazbro]

Originally Posted by Van Diesel

Thanks for the info Uncle Bob!

I just called Airstream again to verify numbers as I want to make sure I’m looking at things correctly.

As you seem quite knowledgeable wanted to run them by you one last time.

The 2013 AI lounge model was built on a Mercedes 3500 chassis (not the 2500). Airstream again verified the tow weight is 7500 (I mistyped above when I wrote 7400). They also verified the tongue weight is 750 pounds. This is also what Mercedes lists for the 3500 lounge model for 2012 (chassis year).

Dry weight of AI lounge model is 8860.
Dry weight of 23fb is 4806.

The hitch weight of the trailer is 467. I know this can change and will weigh it before taking off!

From what I gather, I want to keep hitch and tongue weight at 10% to 20% under tongue and tow weight.

So… 600-675 max tongue and 6000-6400 max towing. I say 6400 as that is the number listed in our brochure.

Does this sound correct in your experience?

What is the GVWR of your AI lounge mode?

IF it is 10,000lbs (you haven't said) minus 8860lbs dry weight (curb weight would have be better as would include fuel) would be 1140 lbs minus fuel to find out payload lets say 1,000lbs payload (you haven't said) minus 500 lbs tongue weight leaves 500lbs minus average 150lbs each 2 adults leaves 200lbs minus 75lbs average 2 children leaves 50lbs for food, water, clothes, cooking stuff and everything else.

[AA13]

Originally Posted by Wazbro

What is the GVWR of your AI lounge mode?

IF it is 10,000lbs (you haven't said) minus 8860lbs dry weight (curb weight would have be better as would include fuel) would be 1140 lbs minus fuel to find out payload lets say 1,000lbs payload (you haven't said) minus 500 lbs tongue weight leaves 500lbs minus average 150lbs each 2 adults leaves 200lbs minus 75lbs average 2 children leaves 50lbs for food, water, clothes, cooking stuff and everything else.

Thanks Wazbro!
AI GVWR is 11030. Payload is 2286.

23fb GVWR is 6000. Payload is 1194.

[uncle_bob]

Originally Posted by Van Diesel

Thanks Wazbro!
AI GVWR is 11030. Payload is 2286.

23fb GVWR is 6000. Payload is 1194.

Hi

Ok, that's some of the numbers you need. You *also* need the GCVWR for the 3500 chassis.

From what I can see on the internet the 7500 "towing" number is the limit on the hitch as it attaches to the frame. In some cases it becomes the limit, but not in all cases.

According to this site:

https://www.mbvans.com/en/owner-manuals

and the owners manual for your van, Mercedes spec's the GCVWR at 15,250 pounds. ( Page 329 ). Any time the trailer + van + stuff adds up to more than 15,250 you are "over limit". If your van is at 11,030 loaded up then the trailer can be 15,250 - 11,030 = 4,220 pounds.

If the van has nothing in it. No fuel, no passengers, no water, nothing at all, you get another 2,286 on top of the 4,220. I most certainly would head over to a CAT scale and check the "empty weight" on the van you have. Typically folks are surprised ( ... not in a good way) when they do this.

If you have things like a shank and WD hitch, they also go into this number. Any other "add on's" get counted as well.

With a normal load of passengers, water, and other goodies, it's rare to be under 1,000 pounds for "passengers / payload / hitch" on one of these vans. There are a lot of folks that struggle to stay under the max limit.

Do you want to tow down the road right at the "max limit" of your lash up? I'd suggest not. The payload numbers *assume* you are at max on the front axle and max on the back axle. That rarely is the case. Making *sure* means heading over to the CAT scale at the start of each trip ... yuck ....

To complete out the math:

Empty 23' is 4,806 pounds (likely more ...)
Empty Van is 8,844 pounds (also likely more on a real van)

With no hitch involved that comes to 13,550 pounds vs the 15250 limit. You have a whopping 1,700 pounds for all additions. If the numbers are off by 5% (as some have found) ... you have even less.

Toss in a hundred pounds for shank and hitch (could easily be more) and you are down to 1,600 pounds. Put in 25 gallons of fuel and you loose another 175 pounds.
25 gallons of fresh water in the van and 25 gallons of fresh water in the trailer pull out 416 pounds.

That combo has right at 1,000 pounds "to spare". There's no driver or passenger yet. We also don't have any beer or socks onboard. If you are trying to stay 10% under the GCVWR limit, you already are well past that point.

So, could you? Sure, just don't have anything in either vehicle. Should you? Nope

Bob

[AA13]

Thanks so much for all the info and explanation.
Really appreciate your time and expertise.

[uncle_bob]

Hi

No problem.

The same "fun" applies to the "modern" vans. I went through all of this trying to figure out what I could or could not tow with the X ....

Enjoy !!!

Bob