Fuel planning >> worst-case requirement

More
03 Nov 2012 07:11 #1 by dandjcr
dandjcr created the topic: Fuel planning >> worst-case requirement
Forum Home > On the Road > Fuel planning >> worst-case requirement

OKA4WD.com
Administrator
Posts: 412
From Tony Lee:

One of the things on my to-do list is to add some extra fuel capacity so I can do the usual trips (that one buys an OKA to do) without hanging jerrycans all over the back.
I have some figures gleaned from various personal web sites, but would appreciate any info that would help plan how much extra capacity I should add.
I guess there is one particular route that has the worst combination of distance between fuel supplies and low-speed/high-consumption terrain and that might serve as the benchmark for me to work on.
Thanks
Tony
April 18, 2010 at 10:49 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From Peter_n_Margaret:

Hi Tony (XT123.......
We carry 280L in the "main" tanks and plan our re-fuelling based on 25L per 100km for most 'tough' routes, although the average consumption has never exceeded about 22L/100km over the full capacity. Our trip averages are 17-18L/100k or around 19 and a bit, towing a boat.
On 'normal' desert roads a planning figure of 20L/100km leaves a safety margin.
Frankly 200-250L is plenty. With your weight and frontal area, you should be even better off than we are.
It is easy to confuse range with saving a few $$s and with 280L we can often skip the most expensive places.
Cheers,
Peter (XT196)
April 18, 2010 at 10:50 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From Tony Lee:

Thanks Peter.
The supplementary question is of course - (without going stupid and driving around Uluru a thousand times) - what is the longest stretch of desert road without a fuel stop.
April 18, 2010 at 10:51 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From David Ribbans:

Tony,
Following on from Peter's reply, we routinely get 7 km/l (14l/100km) from our Oka (but we rarely go over 80 kph which is when fuel consumption rises) and the worst we ever got was 4.4 km/l (22l/100km) when we were in the top end sand dunes of the CSR in low ratio for seven days. Gravel roads don't seem to affect consumption, deep sandy tracks do.
We have two standard 105 Litre side tanks plus 50-60 L in a rear tank plus we can carry two jerry cans if necessary, which we have never used. I reckon 250 L is about optimum and gives a 1200 km safe range. Spreading fuel over several tanks is a good safety feature as you never know when one will leak (or some gets stolen as happened to us in Kununurra, lost 40 litres).
Fuel cost when you are very remote is seldom a consideration, availability is more important. If you pass by an expensive place, murphy's law says the next one will be even more expensive and/or they will have run out. In the desert, fuel can be more important than water. With fuel you can go and find water, the reverse isn't true.
The longest desert trek we've had without fuel is from Kunawaritji (Well 33 on the CSR) down the Gary Highway/Gunbarrel Highway/Great Central Road to Warburton. 800 kms and we never saw a single vehicle or person in five days.
Coober Pedy to Ilurlka on the Anne Beadell comes in a close second at 750 km.
Third would probably be Well 33 via the CSR to Georgia Bore, then via Rudall River on the Talawana Track to Newman which seemed like a very long way (700 km).
Unless you go somewhere really off the track that's probably about as far as there will be without fuel.
April 18, 2010 at 10:54 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From Tony Lee:

That's encouraging. Even at 22L/100km - your absolute worst figures - 800km requires 176L which gives a reasonable margin in 210L tanks. Add another 40L and there should be plenty.
I'm going all-diesel (plus solar of course) with cooking, heating and hot water, but I intend having a separate 20L tank filled via a superfine filter from the main tank for that (because of crappy diesel quality overseas) so I will have to factor that in to the calculations if I start pinching fuel out of the main tank.
April 18, 2010 at 10:55 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From David Ribbans:

Tony, we've never let our side tanks get below around 10-15 litres. At that level you can't trust the gauges or the pick up level, or the muck that might be floating around in the bottom of the tank, so 210 L might only be 180 L of useable fuel.
I'd hate to have to learn how to bleed the system sitting on the side of the road somewhere remote.
April 18, 2010 at 10:56 PM Flag Quote & Reply

OKA4WD.com
Administrator
Posts: 412
From Tony Lee:

Current bus has approx 700Litre tank and being US manufacture, has the pickup on the right side of the transversely-mounted tank. No fuel gauge.
Missed a critical fuel stop once and then the next fuel outlet was closed and according to the dipstick, the tank was bone dry. Spent the next 50km driving on the wrong side of the road so the fuel would be on the pickup side. Apparently sometimes impossible to get it bled so I was happy to get to the next SS still running.
Always wondered why getting low on fuel would cause special problems with muck/water in the bottom of the tank. Tank bottoms rarely have a drain well to trap the water, the pickup is always right at the bottom anyway, the fuel is always sloshing around and every time the tank is filled, it always stirs it all up.
I guess if there was stuff floating on the surface ...
April 18, 2010 at 10:58 PM Flag Quote & Reply

Hal Harvey
Site Owner
Posts: 510
Just in case anybody was ever wondering whether the original XT/LT tank really was the stated 105-litre capacity, I can confirm that it is. I'm dumb enough to risk the bleeding thing and ran one bone dry recently - the fuel gauge was in the red, but not below it - and then switched tanks while it was trying to run on air, recovered OK, carried on to the next servo where I filled the dry tank up to the filler lip - 105 litres on the dot.
I believe NT tanks are bigger (longer).
--
Hal

April 18, 2010 at 11:03 PM Flag Quote & Reply

Peter_n_Margaret
Member
Posts: 198
I usually run the fuel out before switching tanks.
No problem.....

Cheers,
Peter
--
Cheers Peter, OKA196 Motorhome. www.oka4wd.com/xt196.htm



April 19, 2010 at 8:57 AM Flag Quote & Reply

Dean & Kaye Howells
Member
Posts: 79
From Tony Lee:
Current bus has approx 700Litre tank .......
Is this a mis-print ? with this much fuel who cares ?

Deano:)
April 19, 2010 at 6:55 PM Flag Quote & Reply

Hal Harvey
Site Owner
Posts: 510
Dean & Kaye Howells at 05:25AM on Apr 19, 2010
From Tony Lee:
Current bus has approx 700Litre tank .......
Is this a mis-print ? with this much fuel who cares ?

Deano:)
Not a misprint I reckon - if you read Tony's profile it says: "Betty and I are officially collectors of motorhomes - have a 40' self-converted MC8 tag axle bus in Oz, a small ClassC in Germany and a 35' Airsteam Cutter in the US" ... plus the OKA... so we can guess he wasn't talking about the OKA at the time! Interesting people.
--
Hal

April 19, 2010 at 7:03 PM Flag Quote & Reply

Tony Lee
Member
Posts: 540
The bus - as in MCI ex Ansett Pioneer - gets a whopping 2.4km per litre so it needs a big tank to get across the Nullarbor without refuelling. No fuel gauge either and a major, major problem to bleed it if it does run empty so that adds to the uncertainty. Was much more pleasant to pay the Visa card after the trip across in the OKA than it was in the MCI
--
Tony

picasaweb.google.com/114611728110254134379

April 29, 2010 at 5:38 AM

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum