View Full Version : Tankering

6th Dec 2007, 21:44
One has noticed that the price of fuel appears to be creeping up. Therefore one is taking advantage of cheaper petrol stations/money off vouchers and putting lots of juice in at once.

Anyone know at what point taking fuel on increases weight to the point that fuel burn to carry said fuel increases so that it is not economical to carry so much? I Think. Sorry, not well worded but cider is kicking in.

6th Dec 2007, 21:59
I think it would depend on the size of carrier and journey involved, a difficult science unless you are in the business.

Anyways yes for sure fuel price has increased dramatically over recent days.

6th Dec 2007, 22:02
You should buy the dehydrated petrol as that's by far the cheapest to carry around.

6th Dec 2007, 22:07
Ah, Aaaaaaaaaaaaaaaargh

That'll explain why me local garage is offering discounted lightweight fuel, but does it work in an Audi diesel? Anyways WTF is LPG, really?

Howard Hughes
6th Dec 2007, 22:07
Surely tankering in your average car sized tank shouldn't hurt your economy!

Lets take a tank size of around 60 litres (around 48 kg of fuel). Now my car burns around an extra .1 litre per 100klms for every extra person that I carry. Given that the average person weighs approximately twice the tank of fuel, that means that for each 100 klms I burn an extra .05 of a litre!

My tank generally gives me around 600klms of travel from a full tank, so 6 x .05 = .3 of a litre extra fuel consuption if the tank is full, now of course this doesn't take into consideration the fact that the weight penalty reduces as fuel is burnt.

Now fuel in Australia is pushing $1-50 per litre, so it costs me an extra 45c over the entire tank full, which means that if I can save more than 1c per litre, it is well worth filling up.

Although this is only a very simple summary, it is definately worth filling your tank especially if you are making a considerable saving per litre.

Cheers, HH.:ok:

6th Dec 2007, 22:10
Adding the required aviation touch...

If memory serves, there was a frequent poster to the Corporate threads on a US-based aviation forum who had built an Excel spreadsheet that helped analyze the costs/benefit of tankering. He was giving it away for free to interested professionals.

Con-Pilot would likely know who I'm talking about and how to reach the fellow.

6th Dec 2007, 22:37
I'm sure you offer a fine reference, and thanks for the aviation related balance.

My fuel costs have gone through the roof recently and it is difficult to pass this on to customers in anyway shape or form.

The question at the back of my mind is how is this driven? I'm + 40 years now so my memory isn't what it was. I thought a couple of weeks ago we were discussing oil reaching the "mythical" $100/barrel, I thought we peaked at 99 and a little. Today, I can't be doing with the searching, but I think around the $96/barrel mark.

The punters, and this means most economies that rely on transiting goods, are in she sh!t because here in the UK prices continue to rise.

It is tough at the minute in all respects, still not sure about the base rate decrease announced today :hmm:

6th Dec 2007, 23:24
but I think around the $96/barrel mark.

No, down to 88 USD a barrel today.

6th Dec 2007, 23:36
Looking at a fixed-point price of any commodity is deceptive. The basic element time must be factored in.

To do this (and you can play this game on Yahoo finance), we would look at the price chart of the commodity over time and lay moving averages onto it.

I might pick a 200-day exponential moving average as a slow oscillator, and a 50-day EMA as the faster oscillator. Are these two moving averages converging or diverging over time? Is the slower (long-term) oscillator above the faster (near-term) one, etc?

Even with the recent retraction in price from the recent high for, lets say, West Texas Sweet Crude (WSI), the faster oscillator is above and accelerating away from the slower. Thus, the long term price trend continues upwards.

7th Dec 2007, 03:03
Anyways WTF is LPG, really?

It depends, really.

In some parts of the world it is mostly propane; in others a mix of propane and butane with a few other goodies thrown in. Depands on the required vapour pressure. Around here it is normally about 95% butane, 4% propane and 1% iso butane.

Burns 'cleaner' than 'petrol' and diesel but can have higher CO emissions than diesel in some applications.

Bet that doesn't help.

7th Dec 2007, 10:15
Personally I have taken to only filling my car to about two thirds when I refuel - extra weight=extra burn! It also makes me feel better when I look at what I am paying.

7th Dec 2007, 10:49
But you also need to factor in the cost of your own time and inconvenience in additional visits to the fuel station, if you don't fill the tank completely. One thing I look for in choosing a car is the size of the tank - the bigger the better.

7th Dec 2007, 11:03
In the early days of my motoring I only bought small quantities of fuel (and only when it was essential). Then there was the 'fuel crisis' where supplies became uncertain and I took to carrying two cans which I would keep filled (together with the tank) from whatever sources were available (though most would only sell a minimum quantity - as well as a maximum). Once the crisis was over I returned to buying only when necessary, though in quantities sufficient to avoid frequent visits.
My current vehicle will travel 600 miles on a tankful, so I tend to fill it when it gets low and do this when I can get the cheapest offer (usually the big supermarket in town) rather than the local garages. Because I (usually) buy in large quantities it's worth going a few miles out of my way to buy at the lower price (sometimes several pence per litre).

7th Dec 2007, 12:07
Two items:

1) The cost of money - Buying too much too soon CAN mean paying interest charges. If you pay bills on time it's no problem, of course.

2) In-town stop-start driving means you are accelerating and braking the extra fuel, thus burning more (and braking more). Steady-state highway driving is much less dependent on extra vehicle weight.

7th Dec 2007, 15:09
Methinks you tankering too much fermented apple juice Paracab! Don't get the idea that I think that to be a bad thing :ok:

7th Dec 2007, 15:26
As I'm used to filling up Jerry cans for the aeroplane, I now fill them up with the car whenever I have a Tesco discount voucher. If I don't use it for flying I transfer it to my wife's car, the lawnmower or to top mine up later on. So far, the most I have paid for petrol is 96.9p (yesterday).

I'm not sure if Tesco are happy with me doing it. Once, the cashier expressed surprise at the capacity of my tank as I paid for 85 litres. However, I see on another thread that maybe I shouldn't be using Tesco stuff in the aeroplane because of the alcohol content.:confused:

7th Dec 2007, 15:33
Off-topic slightly, but fuel burn for long-range aeroplanes like the Airbus 340, plotted as consumption per km, follows a steeply descending curve over short distances then flattens out, bottoming out at about 5,500km then rising again slightly as the fuel penalty for carrying the extra fuel kicks in. So on a sector of 11-12,000km, say London-Singapore, you would burn less fuel by stopping half way to refuel (in theory at least).

Don't think that applies to cars, the weight of a full tank is a much smaller proportion of the all up weight. My guess is that you would run out of fuel before you reached the lowest point in the curve.

7th Dec 2007, 16:10
I believe that UK law restricts you to two two-gallon containers (even when stored in your garage):-
The Petroleum Spirit (Motor Vehicles etc.) Regulations 1929 and the Petroleum Spirit (Plastic Containers) Regulations 1982 limit the amount of petrol that can be kept in a domestic garage or within six metres of a building (e.g. most domestic driveways). The limit is a maximum of two suitable metal containers each of a maximum capacity of ten litres or two plastic containers (which have to be of an approved design) each of a maximum capacity of five litres. These limits also apply to any containers kept in a vehicle parked in the garage or on the driveway (but not to the internal fuel tank of the vehicle). Under no circumstances should the petrol containers be stored in the home itself.

However, :-
Petrol filling stations may have their own internal policy on the types and numbers of containers they are prepared to fill - frequently one or two 5 litre plastic and/or one or two 10 litre metal. This is a decision made by the filling station operator and is not a legal requirement.
Petrol filling stations usually have to abide by a licence condition to allow only 'suitable' containers to be filled. This is usually interpreted as metal containers up to a maximum size of 23 litres or plastic containers up to a maximum size of 5 litres. A licence condition has the same effect as a legal requirement. The licence condition does not limit how many containers one customer may fill.

7th Dec 2007, 18:50
I get mine delivered by the Postie: :E


7th Dec 2007, 19:10
What a great, easy to use site that PetrolDirect is. Just ordered me 200 litres white diesel. Can't believe it's that cheap. :E

Standard Noise
7th Dec 2007, 20:11
One has 93 litre fuel tank and two 20 litre jerry cans. One finds it beneficial when using Tesco's 5 penny off coupons. One likes to obtain VFM.

Julian Hensey
10th Dec 2007, 11:14
Very funny when you do a google search and it reveals the truth...

Petrol Direct - http://www.petroldirect.com/ (http://www.petroldirect.com/)

Spoof mail-order retailer of petroleum products.

10th Dec 2007, 12:37
Very funny when you do a google search and it reveals the truth...

Petrol Direct - http://www.petroldirect.com/ (http://www.petroldirect.com/)

Spoof mail-order retailer of petroleum products.

So, did you fall for it?:E

10th Dec 2007, 12:55
Once read a (presumably spoof) suggestion that when Safeway were doing a '15p off a litre if you spend 100' offer (and the vouchers didn't have a limit on them) that it would pay Tesco/Sainsburies/Asda to send someone to buy 100 worth of stuff then send a tanker round to the pumps.

Don't know if it is coincidence but any of that type of voucher I have had lately has had a 'max 50 litres' or some such on it.

Out Of Trim
10th Dec 2007, 18:15
I've been tankering fuel in my car recently, due to the frequent price rises and I think many more will be doing so too! Very soon.

New Fuel protests have been organised and will begin next Saturday 15th December at 10:00 am at a fuel depot/refinery near you. Just read about it on Sky News.. Nothing about it on auntie BBC:}

Here we go again..