Club 80-90 Forums

What are peoples views on driving with a full or part full water tank? What are the pro's and con's ie:- vehicle stability, fuel consumption etc.

I don't see the point unless your destination is arid or waterless

I carry enough for a three day stint when doing local VW shows

otherwise it's nearly empty, as 40 Litres of water is 40 Kilos of dead weight

I carry enough for the journey, tea etc. and fill up when I get there.
Water is weight and weight is more fuel used.
You shouldn't have any stability problems with a full tank.
Don

I generally don't either for the same reasons as above. Part filled but depends on availability in the country you are touring and wether you are wild camping in it. Greece, we kept it filled and along the way once we left France.

On the basis that we rarely stay in one place for more than one night and are not averse to a bit of wild camping we usually travel with a full tank. But anyway if you do the sums you will find that rolling resistance is almost unaffected by the difference in vehicle weight due to full or empty tank. As my driving technique precludes the use of the brakes for most of the time I do not incur the penalty born of the throttle/brake/throttle/brake driving technique seen even on motorways. Ask your four sets of wheel bearings and tyres and if they coukld speak they would back me up. If you want to save fuel change to narrow tyres pumped up good and hard and cruise on a fast tickover. I have tried tailgaating big wide lorries but it don't half get up their noses and I shouldn't think the smokeies go much on it.
Cheer
Wolfie

Citizen Smith wrote:But anyway if you do the sums you will find that rolling resistance is almost unaffected by the difference in vehicle weight due to full or empty tank.

I don't care how you drive, Gravity pulls objects to earth at 9.8ms2 and as gravity converts mass to weight, the energy needed to move mass away from the point of gravity will be exponentially higher with a larger mass
or..
up hill you'll need more energy to move more weight : thus more fuel .

Kev

Can you explain it again as in "Magnus Pyke" style

a full water tank makes less difference than a full petrol tank, and saves the cost fuel used driving to get water when you get there , and even more than the price of buying bottled water.
and a lot less than carrying a canvas
and steel poled awning........
fat "blingboy" wheels and tyres cost more in fuel than a full water tank ever will......

I just fill the water tank and carry anything and everything else I feel I could possibly need. But then mine's a heavy van anyway ... cos it's a camper.

Ian

I got rid of the big water tank under the bed (Autohomes kamper), I didn't see the point unless planning a trip across the Sahara. One of my reasons for getting rid was because it was difficult to empty and clean out so I figured it could be getting quite manky in there. I now use a smaller container which fits under the sink. This is easier to fill as I can carry it to and from the water source (still quite heavy when full though), I can easilly see how much water I've got left and I can clean it out after a trip. I haven't done wild camping but do travel with enough water fo 1 night just in case, also it's one less thing to bother with on the first night when setting up at a campsite. It's something like 25L capacity and that's enough for a weekend, I use the space under the bed for storage now.

Interesting about getting into a truck's slipstream, I was wondering about this myself as I often find it easier to sit behind rather than try to overtake as I tend to stick below 60mph anyway.

Same could be said for a full fuel tank. My guage tends to hover around the 1/4 mark for everyday use but you notice the difference on performance if its full up which is why I keep it low unless I have a long haul ahead. Chickenkoop and I are big advocates of reducing weight to keep fuel consumption down with a general rule of:

1) If you buy anything to put in the vehicle, try and make sure it has at least two uses and does actually GET used - dead weight is dead weight.
2) If you can replace a heavy board with a lightweight one - do so,
3) Remove anything you're not currently using or only use seasonally.
4) Only carry sufficient water for journey if there is a supply the other end. A two-litre pop bottle is often more than enough on the way there. Agree on portable containers - much better idea.
5) Remove gas bottles when you know you won't need them or even consider a lightweight portable single burner during winter months.

WEIGHT & USE - important whether you own a camper, day van or whatever - "If in doubt, throw it out"

These steps alone will sharpen up performance and save fuel

P.S. - loading up today for a week in Lamarsh (Suffolk) and applying above rules fastiduously! Posiibly a WIKI in this one.

The fridge weighs quite a bit too. I've now got a freestanding one which I left at home when I went to a festival last weekend. I knew I'd be able to buy milk at the site shop every night and this kept fine in a coolbag overnight. When I'm not taking my little daughter camping, I don't bother with the fridge as I don't drink milk or lager - not that she drinks much lager either.
I'd agree that weight makes little difference when you're rolling but, no matter how fastidious you are, you're still going to need to accelerate from standing and to go up hills at some point.

I find that breathing in when going uphill helps.
Seriously though, some of the suggestions here must be so marginal. I have standard kit on board that I take everywhere. The awning, for example. I really could not be fagged to take the thing in and out of the van all the time having considered whether I would or not need it on a trip. Apart from the fact I would be bound to come unstuck.
I generally start off with the water tank about half full. If I am going to a festival I fill it up as standing pipes can be few and far between. I have no idea what the arrangements are for Vanfest but I bet that with hundreds of vans in a quite small area, there will be long queues for water. I will therefore fill her up before leaving.
I will also have a suitable amount of farmhouse cider on board, though perhaps I ought to leave it behind to save on fuel.

rainman wrote:I got rid of the big water tank under the bed (Autohomes kamper), I didn't see the point unless planning a trip across the Sahara. One of my reasons for getting rid was because it was difficult to empty and clean out ........

Same here and for the same reasons, also, that tank is very poorly secured and relies on the seat bulkhead and two straps secured with 2 pop rivets to hold it in place. The more weight you carry the greater the energy required to move it , the effect of a full water tank depends on waht percentage difference it makes when compared to all the other fiitings, accessories, camping gear, unladen weight. I noticed a huge difference in performance, economy and braking force when the van was empty while refitting it . I tend to agree with Covkid, if it's not needed take it out!

Our underfloor tank is VERY securely fastened on and holds 60ltr IIRC. That lasts the 4 of us for 4 days for washing, cooking and drinking when wild camping, the same amount of time we can last with the toilet before we need to 'turn the van round' at an Aire or site. Now that means we can have 4 days of free camping which will far outweigh the cost of the fuel to transport the water.

Just my experience of course ... other opinions are available however wrong