Water Tanks

Good Morning, do members carry a full tank of water whilst touring? I'm of the opinion that driving with 60 litres of water can't help fuel consumption?

I travel with about half a tank. Fuel consumption due to extra weight will be negligible,  compare the weight of the water against the total weight of the vehicle.
When arriving on site, I don't wish to be fetching water , I stopped caravanning years ago.

Usually do, 60kg is less than the weight of my passenger and negligible impact on fuel consumption in terms of a 3500kg vehicle, that said I have weighed van fully loaded with full fuel and fresh water to ensure I am below my 3500kg limit.

I like convenience of arriving on site and not having to visit service point, and having water in case our plans change, otherwise I would have bought a caravan.

60 Litres of water weighing 60 kg's? Don't think so?

I litre weighs 1kg so 60l weighs 60kg. Check G**gle if you need convincing

When you start a journey you can never be sure where you will end up (breakdowns, diversions, etc) or whether their will be water available when you arrive - even major campsites have the occasional service failure. So I usually start with a full fresh water tank and an empty toilet cassette. In the past I have drained water from my tank to help another who travelled without water.

Always full fresh, empty grey, empty cassette, full diesel.
In that way we are covered through to Plan Z!!
If you want to calculate the extra fuel used be sure to use a calculator with lots of zeros in the % scale!!!

I would have thought that EVERYONE would know that 1ltre of water weighs 1kg, critical sometimes to know the basics ! 

VDYBDUB wrote:I would have thought that EVERYONE would know that 1ltre of water weighs 1kg, critical sometimes to know the basics ! 

I was educated in imperial measurements,  a gallon of water weighs 10 lbs.

Back to the OP: There have been perhaps half a dozen threads on this subject in the time that I've been on the forum, and none have ended in consensus.

Very roughly, the forum seems to be divided into two. I'm in the camp that travels the initial leg of a longish journey with fresh water tank empty, and 5l of fresh water in a water carrier inside the van. On a long trip - for example from SE England to Scotland - this can mean ~60 kilos less load for several hundred miles.

Once at the first campsite I then half-fill the tank and continue the holiday with roughly half-full tank. If I know I'm heading off-grid for more than one night, I fill the tank completely at the last on-grid site.

In fairness to the other point of view, I suspect that the actual cost savings in fuel are probably pennies, or tens of pennies, over the course of a 2-week holiday!

It's also worth saying that my van does not have a shower, which means very moderate water usage.

I agree with Ian H,plus full fridge,beer that is ! !   

I always start off with the fresh tank full and waste empty.

On a van weighing, say, 3500kg worrying about any extra fuel used by carrying 60kg of water seems pointless.

A pint of water weighs a pound and a quarter but, yes, 1 litre = 1kg. Anyway, the whole point of a Motorhome is to be self sufficient. People choose one brand over another because it has larger tanks (I believe) so why would you not fill it unless you are on a meter at home and can get it free at first stop (joke!). 
A serious point though, some (mainly Continental) motorhomes have such low user payloads that the manufacturers advise travelling with 25% water on board. Hymer and other have been guilty of this. Pretty disgraceful to have a 100 litre tank but only be able to travel with 25 litres on board.

I agree always travel with a full tank of fresh water you will not know the difference, what I have found though is when I arrive at destination I now have a tank full of not just warm but hot water. On the Broadway the silencer runs directly in front of the fresh water tank about 3 inches away and the heat of the exhaust plus air flow heats the water. I am thinking of getting a sheet of aluminium heat shield material and mounting just infront of the tank.

Windsurf1 wrote:60 Litres of water weighing 60 kg's? Don't think so?

Sorry to continue the Mick take, but if it didn't weigh 1kg/ltr your windsurfer would sink!!!!

I think our van loses water as we travel. I assume it sloshes about and comes out of the vent holes on top of the tank. We seem to have less water at the end of a journey than we did at the start. Is this a problem others have encountered, or is it just us? Our van is a 2006 Pollensa on a Transit base vehicle - if that is any help.

I think it depends on how the motorhome is used.  If like us you only use campsites with a plentiful supply of free fresh water, there is no point carrying more water than you need for the journey i.e. a few litres for which we have a small container.  We always leave home with a completely empty fresh water tank and water system as I will have drained it all down at the end of the previous trip.  On arrival at our first pitch I fill the fresh water tank, usually with a water barrel, and fill the hot water tank and prime the system.  We don't normally use the motorhome for day trips so we expect to remain on the pitch until the end of our stay.  I run down the fresh water tank so the morning we leave the pitch there will only be a small amount of water left in the tank.  If there is more than I need for the journey I use some to flush the waste water tank and pipes.  I don't drain the hot water tank or the rest of the water system until I leave the last pitch of our trip and head home.  My motives for travelling with a minimum of water is to save weight which improves fuel economy and handling and makes the van less sluggish.  I believe it's also advantageous to start on each pitch with the freshest water possible.

Needless to say, I always travel with completely empty grey and black water tanks.

I always thought carrying half a tank of water was bad form as it sloshes about and causes more stresses.
There is no straight answer, if heading to a club site I probably wouldn't bother to take a tank of water with me, heading off in to the boonies then its a tank of water plus two jerry cans of 25L each. Might cost a few cents extra to carry it but if you are stuck in the a*se end of nowhere without water that is a money well spent.
Our van weighs 3880kgs laden and will out drag many city cars so the difference the extra water makes to performance and cost is negligible, if I wanted to save money on fuel I would just back off a few clicks. On a small van of course it may be a different story.

Slow-Lane wrote:I think our van loses water as we travel. I assume it sloshes about and comes out of the vent holes on top of the tank. We seem to have less water at the end of a journey than we did at the start. Is this a problem others have encountered, or is it just us? Our van is a 2006 Pollensa on a Transit base vehicle - if that is any help.

Your van will have vent holes in the top four corners of the tank.  It would have had nylon inserts in each hole that were pushed up by water surges and sealed the hole but they will have gone and the water surges out when you brake. When I had a van with a tank of that type, I had those four holes sealed and a new vent taken up to the filler. The work was done by the as service centre st Willersey probably in 2005 , and that solved the problem.

Peter Brown wrote:

Slow-Lane wrote:I think our van loses water as we travel. I assume it sloshes about and comes out of the vent holes on top of the tank. We seem to have less water at the end of a journey than we did at the start. Is this a problem others have encountered, or is it just us? Our van is a 2006 Pollensa on a Transit base vehicle - if that is any help.

Your van will have vent holes in the top four corners of the tank.  It would have had nylon inserts in each hole that were pushed up by water surges and sealed the hole but they will have gone and the water surges out when you brake. When I had a van with a tank of that type, I had those four holes sealed and a new vent taken up to the filler. The work was done by the as service centre st Willersey probably in 2005 , and that solved the problem.

Many thanks for the information. I'll plan making a similar change to ours.  We don't normally travel with much in the tank, but on occasions when one does want to arrive somewhere with a tank of water it's annoying to find quite a bit of it's gone on arrival.

groundhog wrote:I always thought carrying half a tank of water was bad form as it sloshes about and causes more stresses.

That's true - I had forgotten about that aspect.

You get two unwanted effects - one being the extra stress on both tank and mountings under heavy braking, and the other being the "weight transfer" effect on cornering, where the water mass hits the side or end of the tank a few fractions of a second after you turn into a corner. With half a tank being 30 kilos (typically) it won't be a big effect, but it's still something that most drivers would probably not anticipate.

Though I suppose you  could argue that if a tank is not safe to cope with the stresses of a 30kg load moving about, it probably wouldn't be safe carrying a static 60kg load either!

As others have already said, there's no clear right or wrong - just pros and cons on each side...

Roopert wrote:

groundhog wrote:I always thought carrying half a tank of water was bad form as it sloshes about and causes more stresses.

That's true - I had forgotten about that aspect.

You get two unwanted effects - one being the extra stress on both tank and mountings under heavy braking, and the other being the "weight transfer" effect on cornering, where the water mass hits the side or end of the tank a few fractions of a second after you turn into a corner. With half a tank being 30 kilos (typically) it won't be a big effect, but it's still something that most drivers would probably not anticipate.

Though I suppose you  could argue that if a tank is not safe to cope with the stresses of a 30kg load moving about, it probably wouldn't be safe carrying a static 60kg load either!

As others have already said, there's no clear right or wrong - just pros and cons on each side...

i agree with Roopert and there is a recent documented case on this Forum of a member whose water tank dropped off when they were touring!  I also think it depends on the type of van.  A PVCs' handling is much better than coachbuilts which are rear heavy and front light.  Carrying large volumes of water in a coachbuilt exacerbates this.  Most of us have FWD so the more we can lighten the rear axle and shift weight to the front the better.

The failure point on each of the tank brackets was the corner that, over the years, several technicians bent to get access to the top of the tank without completely dropping it - nobody will be doing that again and I don't plan to lose another tank, I do still travel with it full.

Peter Brown wrote:The failure point on each of the tank brackets was the corner that, over the years, several technicians bent to get access to the top of the tank without completely dropping it - nobody will be doing that again and I don't plan to lose another tank, I do still travel with it full.

I thought you might bite