When is a litre of fuel not a litre of fuel?

[Hypnovan]

I received this info in an e-mail today. I don't know how true it is but it's not as if doing any of this will make anything worse. If you have any thoughts on this, do let us know.

hv

"Here at Marian Hill Pipeline where I work in Durban, we deliver about 4 million litres in a 24 hour period thru the pipeline. One day is diesel; the next day is jet fuel, and petrol, LPR and Unleaded. We have 34 storage tanks here with a total capacity of 16,800,000 litres. Only buy or fill up your car in the early morning when the ground temperature is still cold.
Remember that all Service Stations have their storage tanks buried beneath the ground. The colder the ground the more dense the fuel. When it gets warmer petrol expands, so buying in the afternoon or evening .......... your litre is not exactly a litre. In the petroleum business, the specific gravity and the temperature of the petrol, diesel, jet fuel, ethanol and other petroleum products play an important role. A one degree rise in temperature is a big deal in this business but the Service Stations do not have temperature compensation at the pumps.
When you are filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages; low, middle and high. In slow mode you should be pumping on low speed, thereby minimising the vapours that are created while you are pumping. All hoses
at the pump have a vapour return. If you are pumping on the fast rate, some of the liquid that goes into your tank becomes vapour. Those vapours are being sucked up and back into the underground storage tank so you're getting less worth for your money. One of the most important tips is to fill up when your tank is HALF FULL . The reason for this is, the more fuel you have in you tank, the less air occupying its empty space. Petrol evaporates faster than you can imagine. Petroleum storage tanks have an internal floating roof. This roof serves as zero clearance between petrol and the atmosphere, so it minimises the evaporation. Unlike Service Stations, here where I work, every truck that we load is temperature compensated so that every litre is actually the exact amount.
Another reminder. If there is a fuel truck pumping into storage tanks when you stop to buy, DO NOT FILL UP. Most likely the petrol/diesel is being stirred up as the fuel is being delivered and you might pick up some dirt that normally settles on the bottom.

Hope this will help you get the most value for your money. Remember to always fill your car when the tank shows 'half'. Always fill up in the early morning. Always fill up in slow mode. "

[Gadders]

Mmmmm,interesting one that Hypnovan.

[vwjon]

well for the most part what rot!

go out when its frosty, dig a hole in your garden, 10ft deep is it frozen? nope!! if the ground was on fire and you dug the same hole will the ground at 10ft deep be hot??? no way! fuel tanks are burried deep so the surface temp doesnt make any differance to the fuel going into your tank!

vapour return.....exactly how much vapour do you expect to lose? if the air temp was 40*c a litre of petrol would still take 15-20 mins to evaporate, as it only takes 5-10 mins to fill your tank you will lose a cup full to atmosphere, can you not smell it when you fill up? if the vapours were being sucked back there would be no smell!!
the return pipe is for the shut off system, when the car tank is full the fuel backs up and returns to the main tank after the lever has clicked off (you dont pay for any returned fuel)

also if the fuel down the road was 1pence per litre cheaper, a caravelle tank is 90 litres, so even if you were empty you would save 90pence or about a litre, would you save more than that if you filled up at the first station? (YES)

wether the fuel is warm or cold a litre is a litre, when its cold its just denser and depending how your vehicle is tuned depends wether it runs rich or lean, modern cars with lambda probes can adjust accordingly, but our carby and old injection systems dont.

the same does happen for diesel, remember the old days when it froze the diesel "waxed" it became so dense it started to go solid, think about any oil the warmer it is the easier it is to pour.

well thats enough for me! just my tupence worth!

[lloyd]

What a bunch of undocumented, unscientific, unsubstantiated gobbledygook.... most of which is totally false. Please know what the truth and facts are before posting things like this.

I received this info in an e-mail today. I don't know how true it is but it's not as if doing any of this will make anything worse. If you have any thoughts on this, do let us know.

hv

"Here at Marian Hill Pipeline where I work in Durban, we deliver about 4 million litres in a 24 hour period thru the pipeline. One day is diesel; the next day is jet fuel, and petrol, LPR and Unleaded. We have 34 storage tanks here with a total capacity of 16,800,000 litres. Only buy or fill up your car in the early morning when the ground temperature is still cold.
Remember that all Service Stations have their storage tanks buried beneath the ground. The colder the ground the more dense the fuel. When it gets warmer petrol expands, so buying in the afternoon or evening .......... your litre is not exactly a litre. In the petroleum business, the specific gravity and the temperature of the petrol, diesel, jet fuel, ethanol and other petroleum products play an important role. A one degree rise in temperature is a big deal in this business but the Service Stations do not have temperature compensation at the pumps.
When you are filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages; low, middle and high. In slow mode you should be pumping on low speed, thereby minimising the vapours that are created while you are pumping. All hoses
at the pump have a vapour return. If you are pumping on the fast rate, some of the liquid that goes into your tank becomes vapour. Those vapours are being sucked up and back into the underground storage tank so you're getting less worth for your money. One of the most important tips is to fill up when your tank is HALF FULL . The reason for this is, the more fuel you have in you tank, the less air occupying its empty space. Petrol evaporates faster than you can imagine. Petroleum storage tanks have an internal floating roof. This roof serves as zero clearance between petrol and the atmosphere, so it minimises the evaporation. Unlike Service Stations, here where I work, every truck that we load is temperature compensated so that every litre is actually the exact amount.
Another reminder. If there is a fuel truck pumping into storage tanks when you stop to buy, DO NOT FILL UP. Most likely the petrol/diesel is being stirred up as the fuel is being delivered and you might pick up some dirt that normally settles on the bottom.

Hope this will help you get the most value for your money. Remember to always fill your car when the tank shows 'half'. Always fill up in the early morning. Always fill up in slow mode. "

[Gadders]

Calm down,they'll be here soon

[lloyd]

Only 47 minutes!

[Gadders]

got other things 2 do with my time,sorry.And ur point is???

[lloyd]

got other things 2 do with my time,sorry.And ur point is???

vwjon stated the facts, not the ficton posted by HV.
Point was for HV... If you don't know what it was, read his posts.

If you've got other things to do with your time, what you here for? Just boosting your post count?

[Mocki]

I received this info in an e-mail today. I don't know how true it is but it's not as if doing any of this will make anything worse. If you have any thoughts on this, do let us know.

"

to be fair, he did say he didnt know if it was true, some of it is, most of it isnt......

the temp of the tank is important, but the pipes are not as far below ground, and are affected by temp.......

Petrol storage contiainers do have "floating ceilings"

Filling faster does discharge more vapour

and petrol and diesel are expensive, so maybe it is worth a try......

[lloyd]

Your statements are true Steve. But very very little volume change between station tank and vehicle tank..... if any. meters are just behind the hose out of pump box. Some also have meters at ground level at bottom of pump box.

Too much is way out in left field. I've managed stations selling 30-50k/week keeping records of what tankers loaded at depot, dropped into tanks, and what pumps recorded out of tanks into vehicles. In cold weather the tankers lost gallons from depot to station tanks... in hot weather they gained. I'm talking 35 to -30 C range. These differences would balance back within half a day in station tank. Volumes recorded at depot and pumped into vehicles was very very close.... only a few gallons different in 10000 at most. This could easily be accounted for in tanker retaining a little because of different positions while discharging. All fuel had to be accounted for... for sales and for environmental reasons... so had to keep very accurate counts of everything.

[Gadders]

Fair point Lloyd,crossed wires as for getting posts up,not that sad.
Nice to hear whats correct though.

[lloyd]

Was only teasing Duane. A little knowledge goes a long way sometimes. I'm no fuel expert, but once in awhile I manage to say something that can be helpful.

[kevtherev]

I'm no fuel expert, but once in awhile I manage to say something that can be helpful.

yeah like... "my round?"

once in a while

[Hypnovan]

Thanks for being your usual balanced self Mocki. I knew I could rely on you. It's was interesting to learn which parts you believed were true.

Lloyd thanks for sharing your experience of running a filling station with us. After you regained the plot - not sure what that was about though i'm always willing to listen - you made quite a lot of sense. Which version I am going to believe doesn't depend on what I choose to believe without evidence, does it? As I said, in the bit you chose to pretend not to read, was that it wouldn't do any harm to try what was being suggested. I like trying out new ideas until i'm satisfied that they either work or don't.

thanks guys,

hv

[Mocki]

im not sure i like the way you like to make out you are analizing people .
you could easily end up pissing people off with that mate..........

try being yourself , and not who you think you are behind the keyboard