Towing with half a tank

[fourwinns6]

I have a 70 gallon fresh water tank and rarely use 50.Been told that I should only tow empty if possible and fill where I'm camping if possible or tow full to avoid sloshing thus eliminating possible sway.Experienced sway with a half a tank once and added 2 anti friction sway control bar's immediately and haven't had any issues since but I am Leary to try a half tank from past experience.Any rule of thumb as to traveling with a 1/2 a tank?

[fourwinns6]

My tank rest's on the rear axle and travels back almost 5 feet,sloshing & sway are a concern but I hate to haul 644 pounds of water only to dump maybe 250 of it for a lighter drive home.Which I seem to do every time we camp.Seem's like a waste of water to me but???

[elivi8]

I travel with a full tank of water every time. The absolute last thing that I want to do when I get to my destination is to find water. I camp to relax and enjoy. I don't want to run around.

Just fill it and have fun!

Ryan

[jimmyinsd]

in the fire service we have the full/empty rule for all non baffled water tender trucks (1000 gallons +) but the smaller tanked trucks dont get the same effect. IMO the tank size and dimensions as well as location on the vehicle ( above/below the center of gravity, all play into the safety factor of traveling with a partial load of water on.

our tank is approx 12" tall 18" wide and 3' long ( 35 gallons IIRC), i wouldnt worry at all about the sloshing effect from that tank being half full. the additional weight on the tongue of my TV is more of a concern for me.

but the most important thing IMO is what you feel, if you arent comfortable, dont do it.

best of luck.

[dadmomh]

We rarely tow with more than maybe 5 gallons tops. Two main reasons....we always camp with water at the site and we have a Pur filter that mounts on the faucet - improves the taste and water quality considerably. The other reason is that water weighs 8.3# per gallon x a bunch of gallons = more weight and even worse mpg. That 5 gallons or so will get us through bathroom stops along the way and that's about all we need. Only on extended trips do we tow with anything in the grey or black....same reason. Grey is almost always dumped before we head out regardless.

[JJBIRISH]

I haul with full tanks but for no other reason than to have plenty of water with me… but you are not going to get a lot of side to side sway from a half full tank in a RV…

Due to its low mounting and small size in a Partially filled RV fresh water tank, the shifting of the water would cause minimal sway force… enough of the water would quickly fill the one side of the tank and begin working against the sideways push of the remaining water acting like its own shock absorber in some respects… so there would be weight shifting but about the only shifting that would matter would be the initial water hitting against the flat side of the tank followed by the self dampening of the rest… the problem would be small and tank baffling would be almost no help in a small tank…

In a tank truck or tank trailer with loads on a higher centre of gravity and a long cylindrical tank the liquid in much higher volumes with longer distances of travel, baffles would make a big difference because even though the same amount of weight is being shifted it is being shifted shorter distances and again it begins to self dampen against the baffles…

I only have a 40 gal fresh water tank in the far rear of my trailer and if the shifting on the water can be felt or cause sway, that’s where it would show the most, I have never noticed it full or half full…

[rbtglove]

Have always towed with fresh tank at least 1/3 to 1/2 full and sometimes full when headed to a no water campground. Tank in both TTs we've had were in front of TT no sway noticed in either case with equal-i-zer hitch.

[GilliedogKiwi]

We sometimes tow with the 86 gal fresh water tank about 1/4 full in case we want water while on the road to our destination. We have never had a problem with sway and we use a Reese Straight Line Dual Cam Weight distribution hitch. It is fantastic.

http://www.reeseprod.com/content/products.aspx?lvl=2&parentid=1600&catID=1665∂=0

Even with bad cross winds we have not experienced sway when driving and have seen other trailers swaying all over the place.

We also put a water filter inline from the water source to the tank when filling at ALL fill up places. Its amazing how the filter takes out all the minerals and gunk from the water.

One person mentioned about putting some water in the black tank and towing to get it clean - we also put in some Calgon liquid and that helps the stuff slide off the sides of the black tank. Its just a water softener liquid.

Angela and Gary

[Supercharged]

fourwinns6 wrote:
I have a 70 gallon fresh water tank and rarely use 50.Been told that I should only tow empty if possible and fill where I'm camping if possible or tow full to avoid sloshing thus eliminating possible sway.Experienced sway with a half a tank once and added 2 anti friction sway control bar's immediately and haven't had any issues since but I am Leary to try a half tank from past experience.Any rule of thumb as to traveling with a 1/2 a tank?

Or is that half tanked.

[hammer21661]

dclaarjr wrote:

Old-Biscuit wrote:
We travel with at least 1/3 tank all the time......great for roadside stops and is enough just in case.

I do this as well. Not only for the reason expressed here, but I have also stopped at places where I wouldn't let the dog near the water let alone use it in my TT. I like to make sure I always have good water available.

I leave the house with the camper full of water just in case the water is bad or the camp ground gets flooded and I have to sleep in the parking lot like my buddy did a week and a half ago. I bring back what I don't use weather it is 1/3 or 1/2 whatever. I always use my water first though,well most of the time.

[dclaarjr]

Old-Biscuit wrote:
We travel with at least 1/3 tank all the time......great for roadside stops and is enough just in case.

I do this as well. Not only for the reason expressed here, but I have also stopped at places where I wouldn't let the dog near the water let alone use it in my TT. I like to make sure I always have good water available.

[DutchmenSport]

I agree with the above... either 100% full or 100% empty. A full tank has no room to slosh. A partial tank will always have shifting water (like at an ocean beach), waves in the tank beating around. If 100% full, there's nothing to "slosh".

Now, your black tank? If you want a good cleaning? Fill it 1/2 full and go for a drive! it will beat everything loose.

[Old-Biscuit]

We travel with at least 1/3 tank all the time......great for roadside stops and is enough just in case.

[Reader1]

At one time DH worked for a company that hauled water and also knew how the military hauled water. His believe is you travel full or empty. I can't explain it - Sorry.

[Gdetrailer]

Sort of depends on WHERE your tank is located.

If the tank is FORWARD of the axles then you may not have enough tongue weight when partly empty. If tank is on or behind the axles towing with a full tank or partial tank may be adding too much weight behind the wheels basically reducing tongue weight.

In any case, one must remember that these tanks DO NOT have "baffles" in them so when towing with a half full tank you WILL experience sloshing effect from the water in the tank.

This can be substantial in your case especially with 50 gallons moving around in a 70 gallon tank. You will have about 400 lbs of water slamming back and forth, this would feel like hitting three big deer at the same time over and over again.

It is for that reason as to why you should either fully fill the tank or only put a few gallon in it. A full tank will not have much if any room for the water to move so it cancels out any potential slamming effect.

I would recommend filling it full and not worry about the extra 20 gallon you don't use..