Got this off my mum today:

PETROL TIPS - info!! (MUST READ)


With Petrol expected to reach £2 per litre by end of 2011 these tips that I received from a friend might come in handy.


TIPS ON PUMPING PETROL


I don't know what you guys are paying for petrol.... I am paying up to £1.35 to £1.50 per litre. My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every Litre:


Here at the Shell Pipeline where I work , we deliver about 4 million litres in a 24-hour period .. One day is diesel the next day is jet fuel, and petrol, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 Litres.


Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the petrol, when it gets warmer petrol expands, so buying in the afternoon or in the evening....your litre is not exactly a litre. In the petroleum business, the specific gravity and the temperature of the petrol, diesel and jet fuel, ethanol and other petroleum products plays an important role.


A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.


When you're 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. You should be pumping on low mode, thereby minimizing 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 to 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 Petrol tank is HALF FULL. The reason for this is the more Petrol you have in your tank the less air occupying its empty space. petrol evaporates faster than you can imagine. petrol storage tanks have an internal floating roof. This roof serves as zero clearance between the Petrol and the atmosphere, so it minimizes 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 petrol truck pumping into the storage tanks when you stop to buy Petrol, DO NOT fill up; most likely the petrol is being stirred up as the Petrol is being delivered, and you might pick up some of the dirt that normally settles on the bottom.


To have an impact, we need to reach literally millions of Petrol buyers. It's really simple to do.


I'm sending this note to about thirty people. If each of you send it to at least ten more (30 x 10 = 300)...and those 300 send it to at least ten more (300 x 10 = 3,000) and so on, by the time the message reaches the sixth generation of people, we will have reached overTHREE MILLION consumers !!!!!!! If those three million get excited and pass this on to ten friends each, then 30 million people will have been contacted!


If It goes one level further, you guessed it..... THREE HUNDRED MILLION PEOPLE!!!


Again, all you have to do is send this to 10 people. How long would it take?



What do you reckon? BS or reasonable?

So if I fill up my petrol tank on a winters morning, then park it back in my heated garage at home, the massive expansion caused by the change in density will cause petrol to come gushing out of my tank? I don't quite think so........

Also this has been debunked on Piston heads a couple of times. The 1st time in its original American form with gallons, Fahrenheit and dollars

i only run on diesel so i dont care

but ive heard some of that before

well its logical. i doubt vapour loss at high pumping speed is going to be worth more than a couple of pence if that. temperature is prolly the most important thing. as for half full tank, what u save, your going to lose by lugging extra weight around, and more.

well when we fill an aircraft from outside storage tanks 7000kg, if we leave it full it will overflow in the hanger as it warms up, but the volume is slightly more than a cars tank, i would think the drive back from the petrol station even a mile would make space for any expansion

Seems they are at it again :-)
Semi reasonable sounding Drivel.

Well the part about storage tanks and floating covers is true enough, eliminating vapour space is a big deal, you can have vapour recovery systems in the correct circumstances.

Whether all that has any carry over to fuel saving I don't know. Evaporation of fuel is all to do with surface area and I don't think you will see major savings by alterning your petrol filling technique.

If you want to know anything about storage tanks, I can probably help its the day job

I used to store a million litres of fuel in an above ground bulk fuel installation and on a hot summers day you could gain 40-50mm per tank with was a few hundred litres. Now the under ground BFI has a fairly constant temperature and maybe fluctuates a mm or so.
Most of that advise has a tiny bit of credibility but is mainly shull-bit.

The Interwebs says yes (regarding density changes)

quote:

---

For every five-degree (Celsius) change in temperature, figure about a 0.5-percent change in density.

---

I pump upto 50,000 L a day and as owelly and others are saying there is fact behind the claims but for the average car its crap.

it's a chain letter, designed to get on your computer. The information might be true, but the $ savings will probably be negligible. I am willing to bet large sums on this!

While most storage tanks are indeed below ground, the temperature at dawn will be the same as the temperature at midday. Winter / summer will also have very little effect. It's the reason ground source heat pumps work, the temperature below ground is pretty much constant!!

This is like when Colin Chapman used to cool the fuel for his cars.

They still do in Moto GP

tony

quote:

---

Originally posted by Marcus
While most storage tanks are indeed below ground,

---

I can't think I've ever seen an above ground storage tank for a forecourt service station outside the MoD and most of those are decommissioned.
Unless we're talking about huge BFI facilities, which don't sell in twenty quids worths, then the time of day or weather will have a undetectable differance. Ihmo of course.