Tongue weight w empty tanks

[RMNummi]

Wondering if anybody else travels w empty tanks and 1 empty bottle to reduce tongue weight. Am I mistaken in thinking that the AS ratings are based on “full load” i.e. full propane and full fresh tank?

[richard5933]

For me having a nearly-full fresh water tank actually improves handling, and if my memory is correct it slightly reduced tongue weight.

It all depends on where exactly the fresh water tank sits in relation to the axles. Ours apparently is slightly rearward of the midline between the axles, resulting in it helping to alleviate the tongue weight.

It does add to the gross weight, but we've always got plenty to spare on that one. I think most people are in a similar situation where tongue weight is much closer to the limit than gross weight. Moving weight further back helps alleviate tongue weight, and have weight down low helps improve handling.

Propane weight will directly affect tongue weight, for sure.

[ROBERT CROSS]

We never have.
All our tow vehicles have had the specs for the job at hand.

As noted above a full FW tank,(between the axles) helps stability. As does proper loading with a level TV & AS.

POI...our AS stated TW was 860lbs.
Actual when loaded..1200.
Note the very minimal CCC. (we have up-graded the axles to 4200)

Sweet Streams...

[AlbertF]

No. On our 22FB (similar to your 23FB in many ways), the water tank is just ahead of the axle. I figure a full tank adds only about 50 lbs to tongue weight while further lowering the centre of gravity of the trailer.

FWIW, we also went from a single 40 lb battery to a pair of golf cart batteries that weigh about 120 lbs. I figure loaded tongue weight is somewhere over 600 lbs, while putting a bit less than 500 lbs on the car.

[RMNummi]

oK, the contradictions on the forums make me scratch my head…..
1. On “must do updates” Dexter 3” Lift. = higher COG doesn’t that mean less stability? Lower is better right?
2. Don’t travel at less than GVWR cuz low weight = lower stability? So travel fat is better?
3. AS TW are always over stated number… whiskey tango fox?

My own takeaways: i need to do some serious CAT scale playtime. I haven’t ever travelled at “full weight”. I always travel on 90% empty water. I always travel on empty grey and black. I don’t use that much propane so I travel w one empty tank. I do one boondocking trip a year on average so majority of trips are made w/o generator and hooked up to campground water. I use micro-weight Helinox camp gear. We don’t haul everything but kitchen sink. In short everything I do is designed to save trailer weight (not because of my little sauerkraut SUV) but for gas mileage. Why would you haul full tanks and a “fully loaded” AS from point a to point b?

Wouldn’t the “ideal” travel weight (if attainable) be the GAWR?

[ROBERT CROSS]

Originally Posted by RMNummi

oK, the contradictions on the forums make me scratch my head…..
1. On “must do updates” Dexter 3” Lift. = higher COG doesn’t that mean less stability? Lower is better right?
2. Don’t travel at less than GVWR cuz low weight = lower stability? So travel fat is better?
3. AS TW are always over stated number… whiskey tango fox?

My own takeaways: i need to do some serious CAT scale playtime. I haven’t ever travelled at “full weight”. I always travel on 90% empty water. I always travel on empty grey and black. I don’t use that much propane so I travel w one empty tank. I do one boondocking trip a year on average so majority of trips are made w/o generator and hooked up to campground water. I use micro-weight Helinox camp gear. We don’t haul everything but kitchen sink. In short everything I do is designed to save trailer weight (not because of my little sauerkraut SUV) but for gas mileage. Why would you haul full tanks and a “fully loaded” AS from point a to point b?

Wouldn’t the “ideal” travel weight (if attainable) be the GAWR?

WOW...that's a LOT of compensation a few MPG.

With our TV it would not make up for the inconvenience of having to undo that compensation when the towing is over.

What I dodo is travel at the sweet spot for the Burb, 55-60 mph.

You are correct though the sauerkraut may not have the calories to do the job.

whiskey, tango, fox, AS has always 'understated' loaded tongue weights.
There is more to payload than axle ratings.

Sweet Streams

Bob
🇺🇸

[PaulBristol]

Originally Posted by RMNummi

oK, the contradictions on the forums make me scratch my head…..
1. On “must do updates” Dexter 3” Lift. = higher COG doesn’t that mean less stability? Lower is better right?
2. Don’t travel at less than GVWR cuz low weight = lower stability? So travel fat is better?
3. AS TW are always over stated number… whiskey tango fox?

My own takeaways: i need to do some serious CAT scale playtime. I haven’t ever travelled at “full weight”. I always travel on 90% empty water. I always travel on empty grey and black. I don’t use that much propane so I travel w one empty tank. I do one boondocking trip a year on average so majority of trips are made w/o generator and hooked up to campground water. I use micro-weight Helinox camp gear. We don’t haul everything but kitchen sink. In short everything I do is designed to save trailer weight (not because of my little sauerkraut SUV) but for gas mileage. Why would you haul full tanks and a “fully loaded” AS from point a to point b?

Wouldn’t the “ideal” travel weight (if attainable) be the GAWR?

1-3 you posted above have theoretical effect or are incorrect. I am not sure you will be able to observe the differences.

The weight of the trailer vs miles per gallon also has theoretical effect. Again I am not sure you will be able to observe the differences.

It is the speed you drive and the wind speed and direction that makes the biggest difference. You will be able to see the difference.

First and foremost, is stable towing. Actual tongue weight must be 10% to 15% of actual trailer weight. Published tongue weights are approximate. Weigh loaded for travel trailer weight. Weigh tongue loaded for travel as well.

The thing that affects the miles per gallon is wind. Small changes in weight don't make a significant difference. A head wind or cross wind can increase fuel consumption by more than 50%. A tail wind can do the reverse.

Wind and travel speed are the same thing. Traveling at 50 mph means basically a 50 mph head wind. Add an actual 10 mph head wind and the effect on the mile per gallon is the same as traveling at 60 mph.

The miles per gallon decreases as speed increases. From 60 mph to 70 mph, the mileage decreases by 50% while towing my trailer. A 10 mph head wind when traveling at 60 mph is the same as traveling at 70 mph with no wind.

I wish you good luck and happy trails ahead!

[ROBERT CROSS]

Originally Posted by PaulBristol

1-3
SNIP QUOTE

The thing that affects the miles per gallon is wind. Small changes in weight don't make a significant difference. A head wind or cross wind can increase fuel consumption by more than 50%. A tail wind can do the reverse.

Wind and travel speed are the same thing. Traveling at 50 mph means basically a 50 mph head wind. Add an actual 10 mph head wind and the effect on the mile per gallon is the same as traveling at 60 mph.


I wish you good luck and happy trails ahead!

^^^^^^^^^^^^^^
YEP

We get almost a one-mile per improvement with the boat.

Bob
🇺🇸

[RMNummi]

Thanks and noted. My head scratch question is still theoretical:
A: Is tongue weight measured at GVWR (max load)?
B: is tongue weight less at GAWR (empty)?
C: which rating is “more” stable to travel at?
D: does a WD hitch add tongue weight or reduce/offset TW?

My own theory: AS factory posted tongue weight is at GAWR. Forum posts: “AS tongue weights are bogus, it’s ALWAYS more” are largely due to the fact that no one typically measures TW at GAWR (which would give you stated AS TW) my theory is that most folks are measuring at partial to full loads.

[ROBERT CROSS]

Originally Posted by RMNummi

Thanks and noted. My head scratch question is still theoretical:
A: Is tongue weight measured at GVWR (max load)?
B: is tongue weight less at GAWR (empty)?
C: which rating is “more” stable to travel at?
D: does a WD hitch add tongue weight or reduce/offset TW?

My own theory: AS factory posted tongue weight is at GAWR. Forum posts: “AS tongue weights are bogus, it’s ALWAYS more” are largely due to the fact that no one typically measures TW at GAWR (which would give you stated AS TW) my theory is that most folks are measuring at partial to full loads.

AS estimates TW. They have no idea how the AS will be loaded.

The TW includes the weight of the hitch.

It's your responsibility to 'measure' it when fully loaded for use.
I am unclear how they would measure it at the axle rating.

Bob
🇺🇸

[AlbertF]

Originally Posted by ROBERT CROSS

^^^^^^^^^^^^^^
YEP

We get almost a one-mile per improvement with the boat.

Bob
🇺🇸

That's very interesting. Hydrodynamics and aerodynamics seem to be much the same thing. The upside hull on the roof of the Suburban must smooth the airflow over the trailer.

We sometimes have a pair of kayaks on the roof of our tow car. I have not noticed any difference in fuel economy as a result.

[ROBERT CROSS]

^^^^^^^^^^

Another interesting plus...less buffeting noise with the windows cracked open, no need to turn on the AC and really blow up the mpg.

Bob
🇺🇸

[Wazbro]

Originally Posted by RMNummi

Thanks and noted. My head scratch question is still theoretical:
A: Is tongue weight measured at GVWR (max load)?
B: is tongue weight less at GAWR (empty)?
C: which rating is “more” stable to travel at?
D: does a WD hitch add tongue weight or reduce/offset TW?

My own theory: AS factory posted tongue weight is at GAWR. Forum posts: “AS tongue weights are bogus, it’s ALWAYS more” are largely due to the fact that no one typically measures TW at GAWR (which would give you stated AS TW) my theory is that most folks are measuring at partial to full loads.

First, AS factory posted tongue weight is when empty without options, this is why a 25' FB 30 amp/single AC and a 25' FB 50 amp/dual AC have the same tongue weight listed and it is possible some things that you can't order a trailer without are counted as options and different trim levels are options Flying Cloud to Classic...

A: tongue weight should be measured loaded ready for travel, however much weight that is.
B: Depends on where everything is loaded in the trailer, most people put stuff where they can fit it in, not necessarily where they would get the right balance.
C: Not necessarily any of them if weight is high or trailer isn't balanced.
D: As far as balance of the trailer NO the WD hitch does not change tongue weight. It does increase tongue weight for hitch/TV capacity by it's weight minus 75 lbs.(75 lbs is the allowance for required equipment most manufacturers use). It does reduce weight for TV rear axle ratings and a small reduction for payload used (possibly not enough to make up for the WD hitch's weight).

[RMNummi]

Thanks.... curious if the listed tongue weight from AS is in fact measured when factory "empty", i.e no propane, no water, no cargo. Is it the same as the weight reflected by AS on their site?

[Bill M.]

Do the Airstream reported tongue weights include two 100 Amp lead acid batteries?

Two propane bottles, empty or full?

My 1988 25' has a loaded tongue weight of 15% of the rig weight. Does that seem a little high?

[RMNummi]

I totally forgot about the batteries. I just switched over to the single 300ah lifpo. Need to measure the difference.

[Wazbro]

Originally Posted by Bill M.

Do the Airstream reported tongue weights include two 100 Amp lead acid batteries?

Two propane bottles, empty or full?

My 1988 25' has a loaded tongue weight of 15% of the rig weight. Does that seem a little high?

Airstream claims tongue weight is with empty trailer, no options, with batteries and full propane. They don't say what kind of batteries and now batteries are optional on most models.
Yes, 15% does seem a bit high, shouldn't cause a problem if it doesn't go over tow vehicle rating.

[Andy543]

15% tongue weight is a bit high. That can promote oversteer and jackknifing when going around a sharp turn. 10% would be preferable. In general, you want tongue weight to be as low as possible without causing trailer sway, which can occur when you go too much below 8%.

[richard5933]

Originally Posted by Andy543

15% tongue weight is a bit high. That can promote oversteer and jackknifing when going around a sharp turn. 10% would be preferable. In general, you want tongue weight to be as low as possible without causing trailer sway, which can occur when you go too much below 8%.

Sorry, but this is dangerous advice in my opinion. For as long as I know, Airstream has recommended 10-15% of the trailer's gross weight as tongue weight, provided it does not exceed the trailer's max tongue weight or the tow vehicle's/hitch rating.

Advising a lower tongue rate percentage is dangerous and will contribute to trailer sway. There is enough evidence for this to state it so bluntly.

True, too much tongue weight can contribute to other problems, but 10-15% is not too much per the manufacturer's recommendation.

Also true that in Europe trailers are routinely towed with lower tongue weights, but it is only because of the considerably lower towing speeds that this can be done safely. At the speeds people town trailers in the US suggestions of lower tongue weights could result in serious problems.

[Andy543]

Originally Posted by richard5933

Sorry, but this is dangerous advice in my opinion. For as long as I know, Airstream has recommended 10-15% of the trailer's gross weight as tongue weight, provided it does not exceed the trailer's max tongue weight or the tow vehicle's/hitch rating.

Advising a lower tongue rate percentage is dangerous and will contribute to trailer sway. There is enough evidence for this to state it so bluntly.

True, too much tongue weight can contribute to other problems, but 10-15% is not too much per the manufacturer's recommendation.

Also true that in Europe trailers are routinely towed with lower tongue weights, but it is only because of the considerably lower towing speeds that this can be done safely. At the speeds people town trailers in the US suggestions of lower tongue weights could result in serious problems.

I was just looking at a 2025 Tundra owners manual. They state that you should keep the tongue weight between 9%-11%. I think the old conventional wisdom of 10%-15% is obsolete, for the safety issue I raised.