FWT: Full or Empty on the road?

[Tombstone1881]

Here's my first noob question;

Do you roll with your Fresh Water Tank full or empty? The reason I ask, is there seems to be two schools of thought on it.

On the one hand, you're adding 8 lb/g of overall weight, and needlessly adding weight doesn't seem like a best practice. On the other hand, you have different fingers. No, the other side is that adding that behind the axle will reduce the tongue weight, and that is a good thing. Plus, there's the convenience of not having to fill the thing up from jerry cans on site.

So what's the experienced opinion? It seems to me like a bit of a trade-off.

Related question #1; If your FWT is only partially full, how much does that water sloshing around affect the handling? Do these tanks have baffles inside to mitigate that? I ask this because I've pulled a half-full 1000g tank trailer, and you could really feel that liquid moving.

Related question #2; The fella that sold me this thing said that when he leaves a site, he opens the draincock and then just heads on home, dribbling water all the way. By the time he's back, the tank is empty. Is that a thing, or was he punking me?

[Phreak480]

Originally Posted by Tombstone1881

Here's my first noob question;

Do you roll with your Fresh Water Tank full or empty? The reason I ask, is there seems to be two schools of thought on it.

On the one hand, you're adding 8 lb/g of overall weight, and needlessly adding weight doesn't seem like a best practice. On the other hand, you have different fingers. No, the other side is that adding that behind the axle will reduce the tongue weight, and that is a good thing. Plus, there's the convenience of not having to fill the thing up from jerry cans on site.

So what's the experienced opinion? It seems to me like a bit of a trade-off.

Related question #1; If your FWT is only partially full, how much does that water sloshing around affect the handling? Do these tanks have baffles inside to mitigate that? I ask this because I've pulled a half-full 1000g tank trailer, and you could really feel that liquid moving.

Related question #2; The fella that sold me this thing said that when he leaves a site, he opens the draincock and then just heads on home, dribbling water all the way. By the time he's back, the tank is empty. Is that a thing, or was he punking me?

1. If I'm gonna carry the weight why not go full.

2. Yes that's a thing, better than draining it all at the campsite and making a mud puddle for the next person.

[Sunseeker16]

I just got back from a trip to Pennsylvania. On a long trip I will carry a third to a half a tank. If i'm doing something local, it's full when I leave the house. Sometimes you can't count on the water quality where you end up.

[Draggo]

I always carry about 5-10 gallons in the tank for bathroom stops when we have a site that has water hookup. If it's a park with no water on the site then I will fill the tank at home so I don't have to mess around with it there. I figure it's less than 300 lbs additional weight total so it's not going to have that big of an effect on my mileage and I'm towing with a 3/4 ton so I'm not concerned about the weight in general on it.

I will say though that I do plan on adding additional supports under the tank this year just to make sure it's solid when traveling after reading horror stories of people having their tanks fall out.

[IsleDog]

Having a single axle trailer, we do not carry water in our tank anymore. our fresh tank is behind the rear axle and severely unbalances our load (removes 80+ lbs from our tongue weight) and we fishtail all over.

1: i have not noticed an issue with sloshing in the tank at partial fill (30 gallons when full).

2: I HIGHLY recommend NOT dumping water on the roads/highway while driving. in the state of Minnesota, you can and will get pulled over for an "unsecured load". we had our fresh tank full with water coming out the vent tube and a state trooper was kind enough to stop us and let us know and gave us a warning for unsecured load.

[Tombstone1881]

Originally Posted by Draggo

I always carry about 5-10 gallons in the tank for bathroom stops when we have a site that has water hookup. If it's a park with no water on the site then I will fill the tank at home so I don't have to mess around with it there. I figure it's less than 300 lbs additional weight total so it's not going to have that big of an effect on my mileage and I'm towing with a 3/4 ton so I'm not concerned about the weight in general on it.

If my spec sheets are to be believed, my PUP's tank is 20g, adding about 170 lbs. maybe? Based on what you're all telling me, that's not a significant enough amount to override the convenience factor(s).

As my Dad used to say; "A difference that makes no difference, is no difference."

Originally Posted by Draggo

I will say though that I do plan on adding additional supports under the tank this year just to make sure it's solid when traveling after reading horror stories of people having their tanks fall out.

Say what, now? Are you messing with me? Is that an actual thing that can happen? Who builds these things?

[flyerdp]

Originally Posted by Tombstone1881

Here's my first noob question;

*SNIP*

the other side is that adding that behind the axle will reduce the tongue weight, and that is a good thing.

*SNIP*

No, this is not really a good thing and will likely lead to dangerous trailer sway. FWIW on my HW 276 and my former PUP the freshwater tank was centered over the axle. The waste and grey tanks are to the rear.

[Rhumblefish]

I typically roll empty, fill up with the nearest potable water, often at the campsite. For me, it's about stress on the system, and I haven't reinforced/added support under the tank ... yet. So I'm always hitting the dump station on the way out (though this past weekend I did have to run up the road a short piece to get to a Love's)

There's no baffles, but the tanks are flat and low. For my 235S, that's up to ~60 gallons of Mother Nature's Finest means up to ~480 of weight to slosh around, but mounted thusly against a 6,000 lb trailer with 4 tires on the ground, it's not as much of an impact as, say, wind resistance at 60 mph. Still, my fresh tank is axle forward.... and rear loading to reduce tongue weight is a sucker play.

I've heard a lot of different ways that people get rid of their excess fresh, everything from running it into the black and gray tanks (seems slow, but takes advantage of your tankage), to dumping on site (which can potentially leave a mud puddle for the next camper). With a big enough valve, you can dump a lot of water pretty fast. I typically get to the road and then pull my fresh tank dunk valve wide open. Tank's done in minutes on a hard surface built to deal with water runoff.

Just my .02. Your mileage may vary.

[Reverse_snowbird]

We tend to run dry with a couple of gallons of water riding in containers in the shower for toilet flushing and hand washing. However, we usually camp where there are water hookups.

In out tt, we hauled water and found that we usually came home with almost as much water as we took. We'd dump the remainder in our driveway when we got home. You DO NOT want to dump water on the ground at a campsite. It's bad manners for the next camper and the water may erode the base of the campsite.

[Tombstone1881]

Originally Posted by Rhumblefish

....my fresh tank is axle forward....

Turns out mine is also, so the whole question is rendered moot.

Note to self: Make sure your question actually applies to your rig.

My FWT is only 20g, so that's generously 160-175 lb.

Originally Posted by Rhumblefish

...and rear loading to reduce tongue weight is a sucker play...

It definitely can be, if you don't know what you're doing. I'm an experienced trailer jockey, but these RVs are new to me, and their weight distribution varies wildly, even without accounting for gear. Trying to dial in that perfect 60/40 isn't easy when you aren't certain of your baseline.

"A man's got to know his limitations." - Clint Eastwood, Magnum Force (1973)

[rfifer]

I'm going to off that "dreaded" reply - It Depends... When we had our pup (HW277), the roof was down and we really could not open it to access the interior until we got to where we were going. So bathroom breaks in the pup just didn't happen. When we got to the campsite, we would hook up the fresh water supply with a filter in the line. Now that we have gone to a larger TT, we do stop and enter the trailer for lunch, bathroom breaks, etc. As such, we did not keep any water in the FW tank of the pup. In the TT, we keep it about 1/2 to 2/3 full. I have never run with the FW drain open on the way home, but I will empty the tank so that it has truly fresh water when we start off.

[kawac14]

The yellow sticker on the door jam of my single axle MicroLite 19fbs shows a maximum cargo carry capacity (dry) of 553 lbs. With a full load of water (357 lbs--including hot water) I would be left with under 200 lbs. of capacity for propane, battery, clothes, food and beer, etc. Therefore, to carry an average amount of stuff and not be overweight, we usually travel with about 5 gallons, saving us about 250 lbs for the other things.

[BjceyzF]

Originally Posted by Tombstone1881

Here's my first noob question;

Do you roll with your Fresh Water Tank full or empty? The reason I ask, is there seems to be two schools of thought on it.

On the one hand, you're adding 8 lb/g of overall weight, and needlessly adding weight doesn't seem like a best practice. On the other hand, you have different fingers. No, the other side is that adding that behind the axle will reduce the tongue weight, and that is a good thing. Plus, there's the convenience of not having to fill the thing up from jerry cans on site.

I travel with a few gallons, enough to use the bathroom between destinations. Some postings here report that the weight of a full tank of water over bumpy roads can break the supports under the fresh water tank.

Moving weigh behind the axle can be dangerous. See:

https://youtu.be/i2fkOVHAC8Q

Some recommend that the tongue weight be 10%-15% the weight of the trailer.

[Portagie1968]

Originally Posted by Reverse_snowbird

We tend to run dry with a couple of gallons of water riding in containers in the shower for toilet flushing and hand washing. However, we usually camp where there are water hookups.

In out tt, we hauled water and found that we usually came home with almost as much water as we took. We'd dump the remainder in our driveway when we got home. You DO NOT want to dump water on the ground at a campsite. It's bad manners for the next camper and the water may erode the base of the campsite.

We have a gallon in the shower also and a gallon in the black tank.

[MT_Camper]

I have a bumper pull toy hauler and for the most part my SxS comes with us camping whether we plan to use it or not. There's way less sway running down the road when I'm hauling it with water in the tanks. The campgrounds we regularly visit that have a water fill station at the entrance have super low water pressure so it takes longer to fill the trailer anyways and by that time I just want to be setup ASAP.

[DannyLori]

I believe it all depends on the type of RV you have. I find no difference at all pulling with a 30-35 gallon tank full or empty. I have a 30ft 5th wheel.

[MisterVick]

I don't have enough head room on my GVWR to be able to travel with water - so I don't.

I wouldn't leave a drain open on the road. I am concerned about getting pulled over because some well meaning public servant "thinks" it might be gray water. Just better to avoid the hassle.

[JimMorrell]

If I'm going to be dry camping, I fill my fresh water tank before leaving home! If not, I put just enough in the tank to handle things while I'm on the road (both ways). I've never had the problem, but some people have reported their fresh water tanks falling to the pavement when traveling full. I have only had well known manufacturers' products and not had that problem. If you have a cheaper unit, you might want to check out the suspension of the tank before running full.

[Rhumblefish]

Originally Posted by Tombstone1881

It definitely can be, if you don't know what you're doing. I'm an experienced trailer jockey, but these RVs are new to me, and their weight distribution varies wildly, even without accounting for gear. Trying to dial in that perfect 60/40 isn't easy when you aren't certain of your baseline.

It's easy to get too focussed on a couple of measurements (GVWR, tongue weight and 10-15%) and forget all about what is really at work when we tow: "Polar Moment of Inertia" ain't an Ursus Maritimus ... but sure can be a Bear.

I post this video ALL the freakin time, and it's definitely worth a watch, all the way through:

https://www.youtube.com/watch?v=JeEEC5eVNCk

Lots going on, but the takeaway is that while distributed weight might make the numbers work, it's a bad practice in reality, drastically reducing stability.

Hope this helps (and sorry to everyone who's already seen that video - and me posting it - over and over again).

[Stovebolt]

Originally Posted by Tombstone1881

Here's my first noob question;

Do you roll with your Fresh Water Tank full or empty? The reason I ask, is there seems to be two schools of thought on it.

On the one hand, you're adding 8 lb/g of overall weight, and needlessly adding weight doesn't seem like a best practice. On the other hand, you have different fingers. No, the other side is that adding that behind the axle will reduce the tongue weight, and that is a good thing. Plus, there's the convenience of not having to fill the thing up from jerry cans on site.

So what's the experienced opinion? It seems to me like a bit of a trade-off.

Related question #1; If your FWT is only partially full, how much does that water sloshing around affect the handling? Do these tanks have baffles inside to mitigate that? I ask this because I've pulled a half-full 1000g tank trailer, and you could really feel that liquid moving.

Related question #2; The fella that sold me this thing said that when he leaves a site, he opens the draincock and then just heads on home, dribbling water all the way. By the time he's back, the tank is empty. Is that a thing, or was he punking me?

I carry a full fresh water tank. I have softened filtered water from home. They were made to carry water.