Outer Limits 4x4 Board

Has anyone ever worked out how muck the extra weight from say long range fuel tanks (full) to standard tank and stopping makes to your km/lts. I often drive Adelaide Melbourne non stop in my 4.2 gutd and just wondered if i really gain. I'm going to Perth next June and could go Adelaide Ceduna in one hit and probably Ceduna/ Kalgoorlie non stop.

Can't say for sure, but I have a friend with dual tanks in his Troopy who keeps just a few litres in the second tank and never fills them both unless travelling a long way simply because the extra 90 litres is an extra 90Kgs to lug around town for no reason.

I used to keep my LongRanger on my Zook only half full unless going off-road, and that was even more relevant than the friend's turbo diesel troopy, because the zook was only a little 1.3litre, so an extra 40Kgs of fuel was noticeable.

Petrol is about 0.7 times the weight of water, so for 100 litres of fuel, the weight would be 70kg plus the weight of the tank (??20kg)

I think you mist my point, I was wondering how much fewer ks would you get lugging around say 100lts of fuel in a long rangr tank against the standard tank size and having to stop the extra times on a trip.

numbnuts wrote:I think you mist my point, I was wondering how much fewer ks would you get lugging around say 100lts of fuel in a long rangr tank against the standard tank size and having to stop the extra times on a trip.

How much difference does carrying an extra person plus their gear make (ie 90kg)????

Is the question you are asking really about fuel consumption or extra weigh???

its about how much extra weight afects fuel consumption

I have no figures to go by, but I'd assume a GU td would pretty much laugh at the extra weight - especially if it is only say 90Kgs - but having to stop and refuel more often would be a benefit I'd consider worth the extra bit of fuel you'd use.
You can avoid having to go into towns and just keep on going on the freeway, and with more fuel on board you can be a bit fussier about how much you pay for your fuel and drive on if it's too expensive.

And of course, if it's ME we're talking about, the less times I stand at a counter looking at chocolates and cold drinks etc, the better for my wallet there too.

numbnuts wrote:I think you mist my point, I was wondering how much fewer ks would you get lugging around say 100lts of fuel in a long rangr tank against the standard tank size and having to stop the extra times on a trip.

Interesting question. From my experience:

Both OEM 75l and long range 120l tanks I could lift by myself, so I doubt if either were more than 30kg. Very rough guess, for larger tank with thicker material, say an extra 20kg.

Extra fuel capacity of 45 litres (barely 2 jerry cans ) at a specific gravity of 737kg/m^3 (http://www.simetric.co.uk/si_liquids.htm) means an extra 33 kg.

So, worst case, I have maybe an extra 50kg on board. When we did the Cape, we left with a vehicle full of grog and water, but on our return had significantly less of both. A dozen wine (15kg), 2 cartons of beer cans (20kg), maybe 30l of water less on board (30kg.) So, returned at least 65kg lighter (haven't considered all the food we were no longer carrying.)

Going up, Brisbane to Rockhampton, fuel consumption was 13.9l/100km (travelling afternoon/evening with aircon.) Returning, 12.9l/100km (travelling afternoon with aircon, stopped overnight, next morning was raining - cool, no aircon.) Rockhampton to Townsville 13.8l/100km (evening/morning, some aircon), returning 13.6l/100km (evening/morning, some aircon.)

So, if the weight made a difference to the economy, it's not much.

You also need to think carefully about how much extra weight you're really carrying. You are carrying the extra weight of the tank at all times, but you're only carrying extra fuel for part of the time. In my case, once I've taken 45 litres out of my long range tank, I'm effectively carrying a full standard tank - from there on, there's no difference in the weight of fuel on board. So I might travel an extra 300-350km with a full tank, and during that distance, I'm carrying an extra 30 or so kg of fuel, which is steadily decreasing.

So, removing 65kg from my load didn't make a huge difference to my economy. The extra 20 or so kg of tank will make less difference, and the extra fuel is only really "extra" for maybe 300km in every 800km.

Now, when I get rich again, and put in a 55l auxiliary, that's probably an extra 30kg of tank and 40kg of fuel. I'll do those sums if and when it happens.

So. Did anybody actually read all that?

Yup

thanks for that, so basically it makes no difference except being able to pick and choose your fuel stops. So my way of thinking is I'm better of with the 280lts i have and can save sometimes up to 40cents a litre by filling in major towns on some outback trips.

thanks for that, so basically it makes no difference except being able to pick and choose your fuel stops. So my way of thinking is I'm better of with the 280lts i have and can save sometimes up to 40cents a litre by filling in major towns on some outback trips.

-Scott- wrote:

numbnuts wrote:Interesting question. From my experience:.....................
.............
So, if the weight made a difference to the economy, it's not much.................
So. Did anybody actually read all that?

Bloody hell, that was a flamin awesome answer!!!

Can't ask for better info than that. Sounds like you really knew the subject, and answered it superbly.

If all questions got answered that well we'd all be really happy little campers.

And yes, I read it, and found it very informative.

Ezookiel wrote:

-Scott- wrote:

numbnuts wrote:Interesting question. From my experience:.....................
.............
So, if the weight made a difference to the economy, it's not much.................
So. Did anybody actually read all that?

Bloody hell, that was a flamin awesome answer!!!

Can't ask for better info than that. Sounds like you really knew the subject, and answered it superbly.

If all questions got answered that well we'd all be really happy little campers.

And yes, I read it, and found it very informative.

Problem is, it would still get asked three times a week