Driving with fresh water tank full - is it OK?

[AWCHIEF]

Originally Posted by Friday

I like to tow full, because I bought a trailer to use it's features. People that don't pee in their toilets or use their ovens confuse me... Just tow a $4000 cargo trailer and put a queen bed in it then...

I have some friends that did just that. They bought a used race car hauler for under 2k, put another couple of grand in it in electrical and plumbing systems. Did all the work themselves and have a first rate hard walled tent. All the comforts of home without the cost of a factory built TT. A plus is that it is watertight with never a leak and if anything breaks they don't have to spend many hours and thousands of dollars to have it fixed.

[Bluto]

Originally Posted by Fly at Night

What if you don't particularly like the taste of water? Could you not fill your fresh-water tank with your favourite beverage? (I like iced tea with pear cider). Then you would have your "ballast" and your favourite beverage on tap to boot.

Would work at an RV park where you can use the site tap for water to make coffee etc., and the communal shower to keep clean.

Better yet, just go where the water tastes like wine.

Canned Heat - Going Up The Country [HQ MUSIC] - YouTube

[Ag&Au]

Originally Posted by Fly at Night

What if you don't particularly like the taste of water? Could you not fill your fresh-water tank with your favourite beverage? (I like iced tea with pear cider). Then you would have your "ballast" and your favourite beverage on tap to boot.

Would work at an RV park where you can use the site tap for water to make coffee etc., and the communal shower to keep clean.

This post's very existence makes me wonder what you put in yours. Personally, I don't want to flush my toilet with 12 year old scotch.

Ken

[Mikethefixit]

When we leave home our fresh water is aways full from our well so we know where the water is comming from. As you can see our AS is a 77 and the tank aint fell out of it yet.

[bovk]

Thanks to all for your insight! I did not expect the result - a majority is for towing with fresh water tank full, there are no concerns about structural problems, loads and so on. Since I have only 20 gal tank, about 170 lbs I am not going to worry abut this and keep it full. Way more convenient on the road and so on. I thought that the post from Andy was funny but then I remembered how much water I needed to refill the cooling system after changing water pump on the road. So again, it is good to have all the water we can carry.

[bovk]

Originally Posted by Inland RV Center, In

Your Airstream is designed to tow with full water.

The biggest reason is that it lowers the center of gravity, making the trailer more stable on curves.

Next reason, and perhaps the best reaso, is what would you do, if your tow vehicle blew a water hose??

Easy answer, the trailer has the water ready for use.

Tape up the broken hose with duct tape, refill the radiator, put the cap back onBUT, do not tighten the cap. You may have to stop every few miles to continue, until you can get the break repaired, but guess where you can get all that water, without any outside assistance.

Safe traveling towing a trailer, has many little kind of things that most people never think of.

But, one big one is, ALWAYS FULL OF WATER.

The loss in fuel economy is so small that it's difficult to even measure.

Andy

Good point Andy,
I just remembered how much water it took to refill the cooling system of the TV after changing the water pump on the road.

Thanks to all for replies, I am going to keep the tank full for all the good reasons above.

[CaddyGrn]

We always begin with a full tank of water, but we are often camping in places that do not have hookups... the only time we do not is in the dead of winter if we are camping to avoid freezing lines and other obvious problems. We always keep the water as full as we can until we return home (just for safety if we break down, or just want another cup of coffee!) then we empty the tank and rinse and refill when we begin our next journey.

[Jim Flower]

I drag the Airstream around because I don't like hotels for business trips or pleasure trips. The airstream is simply more comfortable and has my stuff in it. It is always prepared with full water, propane, and empty holding tanks. It has provided sanctuary during floods, power failures, relative invasion, and numerous Jeep malfunctions. And, frequently, on extended trips, unplanned diversions to no mans land. I rarely use camp ground water hook ups, but always fill up before I leave and empty the holding tanks. Never let your guard down and always be prepared to take full advantage of the best contraption made to allow one to travel well.

[Matt Kline]

Can't do that; she's my brain.....according to her.

[dznf0g]

Originally Posted by Inland RV Center, In

Your Airstream is designed to tow with full water.

The biggest reason is that it lowers the center of gravity, making the trailer more stable on curves.

Next reason, and perhaps the best reaso, is what would you do, if your tow vehicle blew a water hose??

Easy answer, the trailer has the water ready for use.

Tape up the broken hose with duct tape, refill the radiator, put the cap back onBUT, do not tighten the cap. You may have to stop every few miles to continue, until you can get the break repaired, but guess where you can get all that water, without any outside assistance.

Safe traveling towing a trailer, has many little kind of things that most people never think of.

But, one big one is, ALWAYS FULL OF WATER.

The loss in fuel economy is so small that it's difficult to even measure.

Andy

Part of this is anything but true! I won't argue with the stability and convenience benefits (I travel with water when it makes sense), but GM engineering has evaluated that a 10% reduction in curb weight reduces fuel consumption by 6.5%.

You will have to do the math for your particular rig, but accelerating and moving mass DOES COST FUEL! Worth it? Only you can answer that for your own situation.

[TG Twinkie]

30 gallons of water weighs @ 240 pounds. Considering your TV and trailer weight is some 10-11,000 pounds. I doubt that you will see any difference in the mileage when towing with a full FW tank.

[AWCHIEF]

I haved towed with both full and empty water tanks and have seen no measurable differance in fuel usage.

[dznf0g]

Do the math, it comes out to tenths of an MPG based on GCW, Mileage towing,amount of water capacity, anything in black and gray. Higher GCW, less of an effect on a percentage basis.

It is a hard number based in fact....thus the effort to reduce mass through lighter high strength steel and composites. Automakers wouldn't do it...more expensive....if it didn't matter. But 2016 CAFE requires it. Lighter cars and trucks save fuel consumption in the formula stated.

Again, you decide if it is worth it. But to say it has no effect is a disservice and flies in the face of physics.

[dznf0g]

Originally Posted by TG Twinkie

30 gallons of water weighs @ 240 pounds. Considering your TV and trailer weight is some 10-11,000 pounds. I doubt that you will see any difference in the mileage when towing with a full FW tank.

That is true in some cases, but I have 59 gallons + 6 in the HWH + a couple in the lines X 8.2# = 549#s.

BUT, 549# affects a solo 5500# vehicle which gets 17.5 mpg in a more impactful way than 549# affects my 16,000 GCW rig at 9.5 mpg (6.0 liter gas engine comparison)

The math is the math

[Phoenix]

In the desert southwest, we always tow with a full fresh water tank; and we also carry a portable, 7-gallon emergency supply. Water is as important as fuel when traveling in 115-118+ degree weather. Besides, you never know when you'll find a good boondocking spot; and an empty tank will cut your camping time short.

[Inland RV Center, In]

Originally Posted by dznf0g

Do the math, it comes out to tenths of an MPG based on GCW, Mileage towing,amount of water capacity, anything in black and gray. Higher GCW, less of an effect on a percentage basis.

It is a hard number based in fact....thus the effort to reduce mass through lighter high strength steel and composites. Automakers wouldn't do it...more expensive....if it didn't matter. But 2016 CAFE requires it. Lighter cars and trucks save fuel consumption in the formula stated.

Again, you decide if it is worth it. But to say it has no effect is a disservice and flies in the face of physics.

What math?

I understand that GM is a huge Corporation, BUT, what do they know about the aerodynamics of an Airstream trailer??

I totally disagree with their math, as that is not what my many thousands of miles of towing experience demonstated.

My first hand experience showed that is near impossible to tell the difference of mileage when towing an Airstream, with 60 gallons of water, or none, under normal conditions. Normal is not mountain climbing.

Perhaps GM was refering to flat fronted trailers.

Andy

[dznf0g]

This is strictly a weight calculation. 500 pounds of water doesn't care if it is in a square box or a torpedo. Mass is mass. Certainly the aerodynamics of an AS holds a lower drag coefficient.....that has nothing to do with mass penalties.

[BAB]

I bought my Airstream to allow maximum comfort when I travel. When I stay with friends, I spend the night in my own bed. I use my own bathroom and my own shower. Some of us use our trailers for different purposes, but I always fill my water tank before I leave home. If I know I've got campground reservations I may not fill every day, but for my money, I can do without just about anything but water!

[dznf0g]

And I do too, sometimes. For me convenience or time of arrival at the next stop dictates a full tank when I leave home. Other times it is just 10 gallons or so...for the potty and watering the dog, etc. I don't worry about the "slosh" factor in the flatlands....in the mountains probably should be full or empty.
I also do realize the convenience comes with a bit of a price in fuel consumption.....well worth it sometimes for me.

[Frank's Trailer Works]

if I were worried about mpg I would not tow anything and drive a hybrid.