Tonights puzzler.... at what point does extra range become a burden?

[Paddler Ed]

Watching the run up to Bathurst, they were talking about fuel use per lap and the refuelling strategies.

Now a quick search implies that petrol weighs 0.75kg/litre, but at what point does carrying the extra weight when we go bush stop being an advantage? I have a 65ish litre stock tank, so full it weighs about 45kg - which won't make much difference, but a really big long range tank (say 160L, which weighs 120kg full) will start to impact.

Theoretically at what point does that extra weight start to imoact impact on the range of the vehicle? We know that extra weight affects fuel economy, but how much diffeeence does an extra 100kg ish make to fuel economy?

With that difference known, we should be able to work out what impact the extra fuel has, and then see if that negates the benefit of the extra range...

Does any of that make sense?

[rags]

Carrying the 180lts standard in my last Prado never effected my range but the 65 litres in my old triton certainly did. Now days I settle for 150lts in my current prado which travels as far if not further due to better economy than the last model.
Also makes those fuel docket deals worth while

[Joff]

Carrying the 180lts standard in my last Prado never effected my range but the 65 litres in my old triton certainly did. Now days I settle for 150lts in my current prado which travels as far if not further due to better economy than the last model.
Also makes those fuel docket deals worth while

270ltrs in my cruiser and the there us no ill effect. Maybe in girly cars it might be an issue, though ill never know   

[achjimmy]

270ltrs in my cruiser and the there us no ill effect. Maybe in girly cars it might be an issue, though ill never know   

Joff Iam thinking about a long range tank, I have the option between 270 or 220 with 50 of water, only penalty is its a heavier tank and obviously water is heavier too. keen on your or anybodies thoughts.

[Hairs]

I carry full tanks as much as possible, 90lt main 45lt sub.
I use from each alternatively, so over the time(11 years) I have owned the 80(1HDT 91), I haven't worked out if it is better to carry less weight.
I just live with.
I know putting on a roof rack, basket, Awning, Rear Draws(80 kilo with gear), Fridge and recovery gear as well as spares and tools added more Lt/100km,
 
Plan is steel rear bar with wheel carrier, they'll add heaps. 

[patroldude]

270ltrs in my cruiser and the there us no ill effect. Maybe in girly cars it might be an issue, though ill never know   

Ha ha your all over it mate. Have 215L in the patrol - 145L Main tank and 70L reserve. Get around 1100Ks per tank, which runs in around 17L / 100Ks Happy as

So to answer the OPs question, I don't think it really matters. People will carry enough to get them from A to B, where ever they might be


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[jk]

We have the ability to carry 260lt in our 100 Series and I've never thought about it     .  But I guess it's no different to having two fat friends in the back seat    LOL .

The point I think, is that you rarely fill them up completly unless on a big trip where fuel is expensive, hard to get, out in the desert or fuel in your local area is very cheap and your looking to save a few bucks.

But I can tell you it hurts when you fill them up and hand over $350+   

[tombie]

I'd say lack of range is more of a burden...
If you can carry enough to get between fuelling stops plus a margin then you're good to go..


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[McGirr]

I always use the formula below regarding how much fuel to carry

Mark

[Joff]

Joff Iam thinking about a long range tank, I have the option between 270 or 220 with 50 of water, only penalty is its a heavier tank and obviously water is heavier too. keen on your or anybodies thoughts.

I'd always go for range over water under there. I dont like those two part tanks. I prefer a stainless tank inside the back where  it stays relatively cool and you need no pump. Well baffled thou cos sloshing is annoying

[prodigyrf]

Might depend if you're driving uphill or downhill like when I was driving solo regularly between Adelaide and Canberra and could notice the fuel difference, although head winds could easily conceal that difference.

[tk421]

Meh - I get about 1200km out of my Prado fully laden (14-15l/100km), give or take. I'd rather that range than stressing about fuel - (Maree to Alice via Oodnadatta, Binns and Old Andado Tracks without  refueling    )

The American EPA works on each additional 100lbs (45kg) reducing your economy by 1-2%.  This effect is more pronounced in smaller vehicles so lets work on 1% for my Prado. 1 litre of Diesel weighs 0.85kg so my extra 90 litres weighs 76kg fuel (90litres*0.85kg) and decreases my fuel efficiency by 1-2%. (http://www.autoblog.com/2009/10/29/greenlings-how-does-weight-affect-a-vehicles-efficiency/)

Working it out another way - A 2008 report  found that for every 100-kg reduction, the combined city/highway fuel consumption could decrease by about 0.4 L/100 km for cars and about 0.5 L/100 km for light trucks (MIT 2008).  (http://www.nrcan.gc.ca/energy/efficiency/transportation/cars-light-trucks/buying/16755)

So my AU spec Prado carries 180L diesel with its dual  tanks over standard international Spec of 90litres

Using the 2008 report figures - if I didn't have the extra tank or only half filled the car to 90litres my fuel efficiency saving would be 0.5*(100/76)=0.38. Which means my extra 90litres  diesel is costing me 0.38L/100km. But lets no forget that with each KM travelled the weight of the car is decreasing.

I'd get a better saving taking off the Pioneer Platform, awning and bullbar, or not running my aircon 

[tracker]

 MB.....It is what it is........

[gphcald]

i have 159 ltrs (1400 kms to dry tanks approx) in my 95 series Prado TD, that gets me through 2 weeks of driving  (commuting and running around) i normally have approx 45 litres at the end of the fortnight still in my tank.
I really love the ability to do Syd-Bris on one tank as well as my other long trips i save the $ by filling up at cheaper prices rather than paying the higher prices in regional areas.
Fraser last year, Filled up at Gympie, topped up just before the barge and spentr the whole week driving around, my mate in his petty 60 filled up twice at Fraser prices
Just my 2c worth

Rgds

Gerry

[Paddler Ed]

Meh - I get about 1200km out of my Prado fully laden (14-15l/100km), give or take. I'd rather that range than stressing about fuel - (Maree to Alice via Oodnadatta, Binns and Old Andado Tracks without  refueling    )

The American EPA works on each additional 100lbs (45kg) reducing your economy by 1-2%.  This effect is more pronounced in smaller vehicles so lets work on 1% for my Prado. 1 litre of Diesel weighs 0.85kg so my extra 90 litres weighs 76kg fuel (90litres*0.85kg) and decreases my fuel efficiency by 1-2%. (http://www.autoblog.com/2009/10/29/greenlings-how-does-weight-affect-a-vehicles-efficiency/)

Working it out another way - A 2008 report  found that for every 100-kg reduction, the combined city/highway fuel consumption could decrease by about 0.4 L/100 km for cars and about 0.5 L/100 km for light trucks (MIT 2008).  (http://www.nrcan.gc.ca/energy/efficiency/transportation/cars-light-trucks/buying/16755)

So my AU spec Prado carries 180L diesel with its dual  tanks over standard international Spec of 90litres

Using the 2008 report figures - if I didn't have the extra tank or only half filled the car to 90litres my fuel efficiency saving would be 0.5*(100/76)=0.38. Which means my extra 90litres  diesel is costing me 0.38L/100km. But lets no forget that with each KM travelled the weight of the car is decreasing.

I'd get a better saving taking off the Pioneer Platform, awning and bullbar, or not running my aircon 

That's what I was looking for... those sort of numbers (1-2% per 45kg weight) make sense, and what I was driving at.

For example, the guy with 210L of diesel in his 'Cruiser is going to be carrying 155L more than me (so a 3% difference approximately in fuel economy) - at what point does that extra fuel load start to impact his range?

I have 159 ltrs (1400 kms to dry tanks approx) in my 95 series Prado TD, that gets me through 2 weeks of driving  (commuting and running around) I normally have approx 45 litres at the end of the fortnight still in my tank.
I really love the ability to do Syd-Bris on one tank as well as my other long trips I save the $ by filling up at cheaper prices rather than paying the higher prices in regional areas.
Fraser last year, Filled up at Gympie, topped up just before the barge and spent the whole week driving around, my mate in his petty 60 filled up twice at Fraser prices
Just my 2c worth

Rgds

Gerry

I can get fuel cheaper in some regional areas than I can on the Central Coast, and whilst we did a 1700km round trip out towards Cobar, we never paid more than 1.20/L for diesel (and that was with no dockets). I don't always believe that regional is more expensive; I can get 95 for 1.27 at the moment here in Northern Inland NSW compared to ~1.40 around the Central Coast (NSW has great app/website run by the government)

[GeoffA]

At around a grand for a tank, it'll take a LONG time before you come out ahead.

Long range tanks are necessary for remote desert use, but that's about it.
The benefits are debatable anywhere else.

 

[doc evil]

270ltrs in my cruiser and the there us no ill effect. Maybe in girly cars it might be an issue, though ill never know   

Well said there Joffsta...............Who gives a toss, when the tanks are full (300 odd litres) means I'm outta here and on my way bush......................

[austastar]

Hi,
    If and when I get to do the Simpson or similar, my plan is a bit different.
Buy a couple of Jerry cans at the last decent town, fill them at the last decent roadhouse use them to do the distance, leave them at the next roadhouse once done.
Even giving them away to be sold second hand is way cheaper than a long range tank.

Cheers

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[Joff]

Hi,
    If and when I get to do the Simpson or similar, my plan is a bit different.
Buy a couple of Jerry cans at the last decent town, fill them at the last decent roadhouse use them to do the distance, leave them at the next roadhouse once done.
Even giving them away to be sold second hand is way cheaper than a long range tank.

Cheers

Sent from my GT-N5110 using Tapatalk

Sounds great until you have to do it a few times. No one who does big outback trips and has LR tanks would ever go backwards on purpose.

[Joff]

At around a grand for a tank, it'll take a LONG time before you come out ahead.

Long range tanks are necessary for remote desert use, but that's about it.
The benefits are debatable anywhere else.

 

'Necessary' for remote desert? They are not even 'necessary' there either as plenty can testify, but neither is most of the other stuff we all bolt onto our rigs. I once traveled part of the Canning with a mate who carried enough home made bio-diesel to do his trip (Newman, Wiluna, Kunawarritji, Newman) without a fuel stop. He carried it all in 20ltr plastic cube drums in the back of his 80 (Doc will remember Tim's 80 loaded with fuel). Every night he'd pull them all out and stack them so he could sleep in the back.

And, not everyone looks at things like long range tanks in terms of financial return on investment either. The minute you get to a fork in the road and you can turn away from the fuel browser instead of having your journey dictated by where the next fuel is then you have "come out ahead". If you want to do this one 20ltr jerry at a time then go nuts but if not then LR tanks are a good investment in your sanity. If you equate everything in terms of financial ROI then you would never leave home on a decent trip.

 

[Bird]

Sounds great until you have to do it a few times. No one who does big outback trips and has LR tanks would ever go backwards on purpose.

I had a long range tank in the GQ.. no way I'd spend $1000+ again to gain 40 ltrs (got it through a mate who worked at ARB at the time)... 2-3 jerrys at $20ea will suffice.

Patrols have 96l std in the main, and 146l swapped to a Long range tank.. the price just doesn't make sense.

[GeoffA]

.....And, not everyone looks at things like long range tanks in terms of financial return on investment either....

I don't, but Paddler Ed's post ahead of mine seemed to be going down that path...

[Rumpig]

I had a long range tank in the GQ.. no way I'd spend $1000+ again to gain 40 ltrs (got it through a mate who worked at ARB at the time)... 2-3 jerrys at $20ea will suffice.

Patrols have 96l std in the main, and 146l swapped to a Long range tank.. the price just doesn't make sense.

unless you have a vehicle like Joff does which only has a 45 litre sub tank as standard, that gets replaced with a 180 litre tank, bringing it to 270 litre capacity....every vehicle is different, and thus there is no one answer for all.

[Joff]

I had a long range tank in the GQ.. no way I'd spend $1000+ again to gain 40 ltrs (got it through a mate who worked at ARB at the time)... 2-3 jerrys at $20ea will suffice.

Patrols have 96l std in the main, and 146l swapped to a Long range tank.. the price just doesn't make sense.

If all I was getting was 40ltrs in a vehicle like that then neither would I but I bet you wouldn't take it out if it were there to save on weight would you?

[The punter]

The answer to this question involves differential calculus, but I cant remember how to do it!